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Samir rafla principles of cardiology pages 1 61 .. revised


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Part one of my book Principles of Cardiology revised)

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Samir rafla principles of cardiology pages 1 61 .. revised

  1. 1. Principles of Cardiology pages 1-61 ELECTROCARDIOGRAPHY Prof. Samir Rafla The electrocardiogram (ECG) is a graphic representation of the electrical activity generated by the heart during the cardiac cycle. The electrical activity starts from the SA node, bundle of His, right and left bundles, Purkinje fibers to stimulate the ventricles. Waveforms: The waveforms and intervals of the ECG are: The P wave = atrial depolarization. The QRS complex = ventricular depolarization. The Q wave is the initial downward deflection, the R wave is the initial upward deflection, and the S wave is the second downward deflection. The interval from the beginning of the P wave to the beginning of the Q wave is the PR interval. The T wave = ventricular repolarization. The interval from the end of ventricular depolarization to the beginning of the T wave is termed the ST segment. The interval from the onset of ventricular depolarization to end of T is the QT interval. STANDARD APPROACH TO THE ECG: Normally, standardization is 1.0 mV per 10 mm, and paper speed is 25 mm/s (each horizontal small box = 0.04 sec) Heart Rate: divide 1500 by number of small boxes between each QRS. Rhythm: Sinus rhythm is present if every P wave is followed by a QRS, PR interval > 0.12 s, and the P wave is upright in leads I, II, and III. Intervals: PR (0.12 - 0.20 s). QRS (0.06 - 0.10 s). QT 0.43 s; ST-T WAVES: ST elevation : Acute MI, coronary spasm, pericarditis (concave upward), LV aneurysm. ST depression: Digitalis effect, strain (due to ventricular hypertrophy), ischemia, or nontransmural MI. Tall peaked T: Hyperkalemia; acute MI ("hyperacute T"). Inverted T: Non-Q-wave MI, ventricular "strain" pattern, drug effect (e.g., digitalis), hypokalemia, hypocalcemia, increased intracranial pressure (e.g., subarachnoid bleeding).
  2. 2. 2 FIG: The magnified ECG wave is presented with the principal time intervals indicated. Fig: The pathways of Conduction.
  3. 3. 3 RHEUMATIC FEVER Introduction. Classified as a connective tissue or collagen vascular disease, rheumatic fever (RF) is the leading cause of acquired heart disease in children and young adults. a. In many developing countries the incidence of acute RF approaches or exceeds 100 per 100.000, whereas in the Unites States it is estimated to be less than 2 per 100.000. b. Rheumatic fever is more common among population at high risk for streptococcal pharyngitis, those in close contact with school age children, and persons of low socioeconomic status. It occurs commonly between the ages of 5 and 18 years and is rare before 5. Rheumatic fever affects both sexes equally, except for Sydenham’s chorea, which is more prevalent in females after puberty. The clinical manifestations of RF develop after a silent period of approximately 3 weeks following a tonsillopharyngitis caused by a group A streptococcal infection (GAS). Diagnostic criteria 1. The Jones criteria, are designed to aid in the diagnosis of the first episode of RF. Rheumatic fever can be diagnosed when a previous upper airway infection with GA- Streptococci is detected in conjunction with either two major manifestations, or one major and two minor manifestations. Major manifestation includes arthritis, carditis, chorea, erythema marginatum, and subcutaneous nodules. Minor manifestations include: fever, arthralgias, history of tonsillitis 1-3 weeks before the arthralgia, history of rheumatic heart disease; high C-reactive protein, high erythrocyte sedimentation rate, raised antistreptolysin O titer above 200 Todd’s units or prolonged PR interval on electrocardiogram (ECG). Major manifestations: 1. Carditis: affecting 41% to 83% of patients. It can be defined as pancarditis affecting the endocardium, myocardium, and pericardium: The main clinical manifestations include increased heart rate, murmurs, cardiomegaly, rhythm disturbances, pericardial friction rub, and heart failure. Congestive heart failure is rare in the acute phase; if present, it usually results from myocarditis. The most characteristic component of rheumatic carditis is a valvulitis (endocarditis) involving the mitral and aortic valves. Pericarditis may cause chest pain, friction rubs, and distant heart sounds.
  4. 4. 4 2. Arthritis. This is the most common manifestation of RF. It is present in around 80% of the patients and has been described as painful, asymmetric, migratory, and transient; it involves large joints, such as knees, ankles, elbows, wrists, and shoulders. It improves markedly with the use of salicylates within 48 hours of treatment. Monoarthritis, oligoarthritis, and involvement of small joints of the extremities are less common. The arthritis of RF is benign and self- limiting (Lasting 2 to 3 weeks) and does not result in permanent sequelae. 3. Sydenham’s chorea. This extrapyramidal disorder is characterized by purposeless and involuntary movements of face and limbs, muscular hypotonia, and emotional lability. 4. Subcutaneous nodules. 5. Erythema marginatum. Minor manifestations: 1. Fever is encountered during the acute phase of the disease. 2. Arthralgia is defined as pain in one or more large joints without objective findings of inflammation on physical examination. 3. Other clinical manifestations of RF include abdominal pain, epistaxis, acute glomerulonephritis. These are not included as diagnostic criteria for the diagnosis of RF. Laboratory examination and diagnostic testing. 1. Neither throat culture nor rapid antigen test, if positive; differentiate between recent infection associated with RF and chronic carriage of pharyngeal GAS. 2. Antistreptolysin O is the most commonly available test. Elevated or rising ASO titers provide solid evidence for recent GAS infection. A greater than two-fold rise in ASO titers compared with convalescent titers is diagnostic. 3. Increased sedimentation rate. 4. Increased C reactive protein CRP/ 5. The most common finding in the electrocardiogram is the presence of P-R prolongation and sinus tachycardia. Therapy:
  5. 5. 5 Patient with the diagnosis of rheumatic activity should initially receive a full course of antibiotic to ensure proper eradication of the organism. A. Arthritis: Anti-inflammatory medications are generally recommended for 3 weeks for symptomatic relief. 1. Pain resolves within 24 hours of starting therapy with salicylates. 2. If pain persists after salicylate treatment, the diagnosis of RF is questionable. 3. The recommended dose of salicylate is 100 mg/kg per day, given in 4 divided doses. Toxic effects such as anorexia, nausea, vomiting, and tinnitus should be avoided. B. Carditis 1. Strenuous physical activity should be avoided. 2. Congestive heart failure should be treated with appropriate therapy. 3. In patients with significant cardiac involvement, corticosteroids are preferred over salicylates. The recommended dose is 1 to 2 mg/kg per day, (maximum of 60 mg/day as Prednisolone). Commonly, therapy is needed for more than one month in patients with cardiac involvement. Therapy should be continued until there is sufficient clinical and laboratory evidence of disease inactivity. 4. The gradual reduction in steroid doses is important to avoid relapses. Use of salicylates (75 mg/kg per day) while tapering corticosteroids may reduce the likelihood a relapse. Summary: Jones Criteria of Rheumatic Fever Major Criteria Minor Criteria Migratory polyarthritis Fever Carditis Arthralgia Chorea High sedimentation rate Subcutaneous nodules Positive C reactive protein Erythema Marginatum Prolonged PR interval Prevention: The most important step in the treatment of RF is the eradication of GAS infection. Penicillin is the agent of choice. A. best results are achieved with a single intramuscular dose of penicillin G benzathine. b. The oral antibiotic of choice is penicillin V (phenoxymethyl penicillin) (see Table for dosage information). Patients allergic to
  6. 6. 6 penicillin: oral erythromycin can be used. The recommended dosage is erythromycin for 10 days. The maximal dose of erythromycin is 1 g/day. Table: Duration of therapy for secondary prevention of rheumatic fever Disease state Duration of therapy RF + carditis + residual valvular disease At least 10 years post episode and at least until age 40. Lifelong prophylaxis may be required RF + carditis without valvular disease 10 years or beyond adulthood, whichever is longer. RF without carditis 5 years or until age of 21, whichever is longer. RF, rheumatic fever. VALVULAR HEART DISEASE MITRAL STENOSIS ETIOLOGY AND PATHOLOGY: Two-thirds of all patients with mitral stenosis (MS) are females. MS is generally rheumatic in origin. Pure or predominant MS occurs in approximately 40% of all patients with rheumatic heart disease. The valve leaflets are diffusely thickened by fibrous tissue and/or calcific deposits. The mitral commissures fuse, the chordae tendineae fuse and shorten. The valvular cusps become rigid, and these changes in turn, lead to narrowing at the apex of the funnel-shaped valve. Other rare causes of mitral stenosis: Atrial myxoma, ball valve thrombus, congenital and calcific-atherosclerortic disease. PATHOPHYSIOLOGY: In normal adults the mitral valve orifice is 4 to 6 cm2 . When the mitral valve opening is reduced to 1 cm2 , a left atrial pressure of approximately 25 mmHg is required to maintain a normal cardiac output. The elevated left atrial pressure, in turn, raises pulmonary venous and capillary pressures, reducing pulmonary compliance and causing exertional dyspnea. Pulmonary hypertension results from (1) the passive backward transmission of the elevated left atrial pressure, (2) pulmonary arteriolar constriction, (reactive pulmonary
  7. 7. 7 hypertension), and (3) organic obliterative changes in the pulmonary vascular bed. In time, the resultant severe pulmonary hypertension results in tricuspid and pulmonary incompetence as well as right-sided heart failure. SYMPTOMS AND COMPLICATIONS: - Dyspnea, hemoptysis. - Orthopnea and paroxysmal nocturnal dyspnea. Pulmonary edema develops when there is a sudden surge in flow across a markedly narrowed mitral orifice. The cardiac cycle: Simultaneous electrocardiogram and pressure obtained from the left atrium, left ventricle, and aorta, and the jugular pulse during one cardiac cycle. When moderately severe MS has existed for several years, atrial arrhythmias as flutter and fibrillation occur. Hemoptysis results from rupture of pulmonary-bronchial venous connections (apoplexy) secondary to pulmonary venous hypertension. Frank hemoptysis must be distinguished from the bloody sputum that occurs with pulmonary edema, pulmonary
  8. 8. 8 infarction, and bronchitis, three conditions that occur with increased frequency in the presence of MS. Recurrent pulmonary emboli, sometimes with infarction are an important cause of morbidity and mortality late in the course of MS, occurring most frequently in patients with right ventricular failure. Pulmonary infections, i.e., bronchitis, broncho- pneumonia, and lobar pneumonia, commonly complicate untreated MS. Infective endocarditis is rare in pure MS but is not uncommon in patients with combined stenosis and regurgitation. Summary: Causes of hemoptysis in mitral stenosis: - Bronchitis - Congestion - Pulmonary edema - Pulmonary embolism, infarction - Pulmonary apoplexy Thrombi and emboli: Thrombi may form in the left atrium, particularly in the enlarged atrial appendage of patients with MS. If they embolize, they do so most commonly to the brain, kidneys, spleen, and extremities. Embolization occurs much more frequently in patients with atrial fibrillation. Rarely, a large pedunculated thrombus or a free- floating clot may suddenly obstruct the stenotic mitral orifice. Such “ball valve” thrombi produce syncope, angina, and changing auscultatory signs with alterations in position, findings that resemble those produced by a left atrial myxoma. PHYSICAL FINDINGS: Inspection: In advanced cases there is a malar flush. When fibrillation is present, the jugular pulse reveals only a single expansion during systole (c-v wave) (systolic venous pulse). Palpation: Left parasternal lift along the left sternal border signifies an enlarged right ventricle. In patients with pulmonary hypertension, the impact of pulmonary valve closure can usually be felt in the second and third left intercostal spaces just left of the sternum (Diastolic shock). A diastolic thrill is frequently present at the cardiac apex, particularly if the patient is turned into the left lateral position. Auscultation: The first heart sound (S1) is generally accentuated and snapping. In patients with pulmonary hypertension, the pulmonary component of the second heart
  9. 9. 9 sound (P2) is often accentuated, and the two components of the second heart sound are closely split. The opening snap (OS) of the mitral valve is most readily audible in expiration at, or just medial to, the cardiac apex but also may be easily heard along the left sternal edge. This sound generally follows the sound of aortic valve closure (A2) by 0.05 to 0.12; that is, it follows P2; the time interval between A2 closure and OS varies inversely with the severity of the MS. It tends to be short (0.05 to 0.07 s) in patients with severe obstruction, and long, (0.10 to 0.12 s) in patients with mild MS. The intensities of the OS and S1 correlate with mobility of the anterior mitral leaflet. The OS usually precedes a low-pitched, rumbling, diastolic murmur, heard best at the apex with the patient in the left lateral recumbent position. In general, the duration of the murmur correlates with the severity of the stenosis. In patients with sinus rhythm, murmur often reappears or becomes accentuated during atrial systole, as atrial contraction elevates the rate of blood flow across the narrowed orifice (presystolic accentuation). Associated lesion: With severe pulmonary hypertension, a pansystolic murmur produced by functional tricuspid regurgitation may be audible along the left sternal border. Characteristically, this murmur is accentuated by inspiration, and should not be confused with the apical pansystolic murmur of mitral regurgitation. In the presence of severe pulmonary hypertension and right ventricular failure, a third heart sound may originate from the right ventricle. The enlarged right ventricle may rotate the heart in a clockwise direction and form the cardiac apex, giving the examiner the erroneous impression of left ventricular enlargement. Under these circumstances, the rumbling diastolic murmur and the other auscultatory features of MS become less prominent or may even disappear and be replaced by the systolic murmur of functional tricuspid regurgitation which is mistaken for mitral regurgitation. When cardiac output is markedly reduced in a patient with MS, the typical auscultatory findings, including the diastolic rumbling murmur, may not be detectable (silent MS). ECG findings: The P wave is wide and may be notched which suggests left atrial enlargement. It becomes tall and peaked in lead II and upright in lead V1 when severe pulmonary hypertension.
  10. 10. 10 Echocardiogram: Two-dimensional echo-Doppler echocardiography for estimation of the transvalvular gradient and of mitral orifice size, the presence and severity of accompanying mitral regurgitation, the extent of restriction of valve leaflets, their thickness, and the subvalvular changes. Transthoracic and transesophageal echo are needed to verify presence of atrial thrombi.
  11. 11. 11 X-Ray chest: Straightening of the left border of the cardiac silhouette, prominence of the main pulmonary arteries, dilatation of the upper lobe pulmonary veins, and backward displacement of the esophagus by an enlarged left atrium. Summary of signs of mitral stenosis: - Mid-diastolic rumbling murmur with presystolic accentuation; - Snappy first sound; - Opening snap; - Diastolic thrill. DIFFERENTIAL DIAGNOSIS: The apical middiastolic murmur associated with aortic regurgitation (Austin Flint murmur) may be mistaken for MS. However, in a patient with aortic regurgitation, the absence of an opening snap or presystolic accentuation if sinus rhythm is present points to the absence of MS. Tricuspid stenosis, a valvular lesion that occurs very rarely in the absence of MS, may mask many of the clinical features of MS. MANAGEMENT: Penicillin prophylaxis of beta-hemolytic streptococcal infections and prophylaxis for infective endocarditis are important. In symptomatic patients, some improvement usually occurs with restriction of sodium intake and maintenance doses of oral diuretics. Digitalis glycosides usually do not benefit patients with pure stenosis and sinus rhythm, but they are necessary for slowing the ventricular rate of patients with atrial fibrillation and for reducing the manifestations of right-sided heart failure in the advanced stages of the disease. Small doses of beta-blockers (e.g., atenolol 25 mg/d) may be added when cardiac glycosides fail to control ventricular rate in patients with atrial fibrillation. Particular attention should be directed toward detecting and treating any accompanying anemia and infections. Hemoptysis is treated by measures designed to diminish pulmonary venous pressure, including bed rest, the sitting position, salt restriction, and diuresis. Anticoagulants should be administered continuously in those with atrial fibrillation. If atrial fibrillation is of relatively recent origin in a patient who’s MS is not severe enough to warrant surgical treatment, reversion to sinus rhythm pharmacologically or
  12. 12. 12 by means of electrical countershock is indicated. Usually this should be undertaken following 3 weeks of anticoagulant treatment. Conversion to sinus rhythm is rarely helpful in patients with severe MS, particularly those in whom the left atrium is especially enlarged or in whom atrial fibrillation is chronic. Mitral valvotomy by balloon or surgical mitral valvotomy, is indicated in the symptomatic patient with pure MS whose effective orifice is less than approximately 1.3 cm2 (or 0.8 cm2 / m2 of body surface area). Mitral valve replacement by prosthetic valve is resorted to only if the valve is heavily calcified and associated with incompetence. Percutaneous balloon valvuloplasty is an alternative to surgical mitral valvuloplasty in patients with pure or predominant rheumatic stenosis (it is now the first choice). Young patients without extensive valvular calcification or thickening or subvalvular deformity are the best candidates for this procedure. Contraindications of balloon mitral valvotomy: 1. presence of left atrial thrombi, 2. presence of combined mitral incompetence and stenosis, and 3. heavily calcified mitral cusps. MITRAL REGURGITATION ETIOLOGY: 1- Chronic rheumatic heart disease is the cause of severe mitral regurgitation (MR). 2- MR also may occur as a congenital anomaly. 3- MR may occur in patients with infarction involving the base of a papillary muscle. 4- MR may occur with marked left ventricular dilatation. 5- Massive calcification of the mitral annulus of unknown cause, presumably degenerative, which occurs most commonly in elderly women. 6- Systemic lupus erythematosus, rheumatoid arthritis, are less common cause. 7- Mitral prolapse.
  13. 13. 13 Acute MR occur 1- secondary to infective endocarditis involving the cusps or chordae tendineae, 2- in acute myocardial infarction with rupture of a papillary muscle or one of its heads, 3- as a consequence of trauma, 4- or following apparently spontaneous chordal rupture. MITRAL REGURGITATION: SYMPTOMS: Fatigue, exertional dyspnea, and orthopnea are the most prominent complaints in patients with chronic, severe MR. Hemoptysis and systemic embolism also occur less frequently in MR than in MS. Right-sided heart failure, with painful hepatic congestion, ankle edema, distended neck veins, ascites, and tricuspid regurgitation, may be observed in patients with MR who have associated pulmonary vascular disease and marked pulmonary hypertension. In patients with acute, severe MR, left ventricular failure with acute pulmonary edema and /or cardiovascular collapse is common. PHYSICAL FINDINGS: Palpation: A systolic thrill is often palpable at the cardiac apex, the left ventricle is hyperdynamic, and the apex beat is often displaced laterally. Auscultation: The first heart sound is generally absent, soft (muffled), or buried in the systolic murmur. A low-pitched third heart sound (S3) occurring 0.12 to 0.17 sec after aortic valve closure, i.e. at the completion of the rapid-filling phase of the left ventricle, is an important auscultatory feature of severe MR. A fourth heart sound is often audible in patients with acute, severe MR of recent onset who are in sinus rhythm. A systolic murmur of at least grade III/VI intensity is the most characteristic auscultatory finding in severe MR. It is usually holosystolic (pansystolic). In MR due to papillary muscle dysfunction or mitral valve prolapse, the systolic murmur commences in midsystole. In patients with ruptured chordae tendineae the systolic murmur may have a cooing or “sea gull” quality; in patients with a flail leaflet the murmur may have a musical quality. Summary: Signs of mitral incompetence: - Harsh pansystolic murmur over apex propagated to axilla. - Muffled first heart sound. - Systolic thrill over apex.
  14. 14. 14 Electrocardiogram: In patients with sinus rhythm there is evidence of left atrial enlargement (P mitrale), but right atrial enlargement also may be present when pulmonary hypertension is severe. Chronic, severe MR with left atrial enlargement is generally associated with atrial fibrillation. Echocardiogram: Doppler echocardiography and color Doppler flow echocardiography imaging are the most accurate noninvasive techniques for the detection and estimation of MR. The left atrium is usually enlarged. Findings which help to determine the etiology of MR can often be identified; these include vegetations associated with infective endocarditis, incomplete coaptation of the anterior and posterior mitral leaflets, and annular calcification, as well as left ventricular dilation, aneurysm, or dyskinesia. The echocardiogram in patients with mitral valve prolapse is described below. Roentgenogram: The left atrium and left ventricle are the dominant chambers; in chronic cases, the former may be massively enlarged and forms the right border of the cardiac silhouette. Pulmonary venous congestion, interstitial edema, and Kerly B lines are sometimes noted. TREATMENT: Medical: The non surgical management of MR is directed toward restricting those physical activities that regularly produce dyspnea and excessive fatigue, reducing sodium intake, and enhancing sodium excretion with the appropriate use of diuretics. Vasodilators and digitalis glycosides increase the forward output of the failing left ventricle. Angiotensin-converting enzyme inhibitors are given in chronic MR. The same considerations as in patients with MS apply to the reversion of atrial fibrillation to sinus rhythm. Surgical treatment should be offered to patients with severe MR whose limitations do not allow them to perform normal household activities despite optimal medical management. Surgery is indicated when the end systolic diameter of the left ventricle by echo exceeds 50 mm. MITRAL VALVE PROLAPSE Mitral valve prolapse (MVP), also termed the systolic click-murmur syndrome, is a common, but highly variable, clinical syndrome. It is a frequent finding in patients who have the typical features of the Marfan syndrome. The posterior leaflet is usually more affected than the anterior, and the mitral valve annulus is often greatly dilated.
  15. 15. 15 MVP may be associated with thoracic skeletal deformities. MVP is common in females between the ages of 6 and 30 years. Most patients are asymptomatic and remain so for their entire lives. Arrhythmia, most commonly ventricular premature contractions and paroxysmal supraventricular and ventricular tachycardia, have been reported and may cause palpitations, light-headedness, and syncope. Many patients have chest pain which is difficult to evaluate. PHYSICAL EXAMINATION: Auscultation: the most important finding is the mid-or late (nonejection) systolic click, which occurs 0.14 s or more after the first heart sound. Systolic clicks may be followed by a high-pitched late systolic murmur, heard best at the apex. A useful echocardiographic definition of MVP is systolic displacement (in the parasternal view) of the mitral valve leaflets into the left atrium > 3 mm. Thickening of the mitral valve leaflets is present. Doppler studies are helpful in revealing and evaluating accompanying MR. Treatment: The management of patients with MVP consists of reassurance of the asymptomatic patient without severe MR or arrhythmias; prevention of infective endocarditis with antibiotic prophylaxis in patients with a systolic murmur and the relief of the atypical chest pain by beta blockers. AORTIC STENOSIS Aortic stenosis (AS) occurs in one-fourth of all patients with chronic valvular heart disease; approximately 80 percent of adult patients with symptomatic valvular AS are male. Etiology: 1. AS may be congenital in origin, 2. secondary to rheumatic inflammation of the valve, 3. degenerative calcification of the aortic cusps of unknown cause. PATHOPHYSIOLOGY: A peak systolic pressure gradient exceeding 50 mmHg or an effective aortic orifice less than approximately 0.5 cm2 /m2 of body surface area i.e., less than approximately one-third of the normal orifice, is generally considered to represent critical obstruction to left ventricular outflow. SYMPTOMS: AS is rarely of hemodynamic or clinical importance until the valve orifice has narrowed to approximately one-third of normal, i.e., to 1 cm2 in adults. Exertional dyspnea, angina pectoris, and syncope are the three cardinal symptoms. Angina pectoris reflects an imbalance between the augmented myocardial oxygen
  16. 16. 16 requirement by the hypertrophied myocardium and the un-accompanying increase in coronary blood flow. Orthopnea, paroxysmal nocturnal dyspnea, and pulmonary edema, i.e., symptoms of left ventricular failure, also occur only in the advanced stages of the disease. PHYSICAL FINDINGS: A palpable double systolic arterial pulse the so-called bisferiens pulse, excludes pure or predominant AS and signifies dominant or pure aortic regurgitation or obstructive hypertrophic cardiomyopathy. Palpation: The apex beat is usually sustained and displaced laterally, reflecting the presence of left ventricular hypertrophy. A systolic thrill is generally present at the base of the heart in the suprasternal notch, and along the carotid arteries. Auscultation: Harsh ejection systolic murmur over aortic area propagated to carotids. The sound of aortic valve closure, the second sound is very weak or even absent with tight aortic stenosis. Frequently, a fourth heart sound is audible at the apex in many patients with severe AS and reflects the presence of left ventricular hypertrophy and an elevated left ventricular enddiastolic pressure; a third heart sound generally occurs when the left ventricle dilates and fails. The murmur of AS is characteristically an ejection systolic murmur loudest at the base of the heart, most commonly in the second right intercostal space. It is transmitted along the carotid arteries. Occasionally, it is transmitted downward and to the apex and may be confused with the systolic murmur of MR. Summary: Signs of aortic stenosis: 1. Harsh ejection systolic murmur over aortic area propagated to carotids. 2. Weak or absent second heart sound (aortic component) 3. Systolic thrill over aortic area, suprasternal notch and carotids. 4. Strong sustained apex, Electrocardiogram: This reveals left ventricular hypertrophy in the majority of patients with severs AS. Echocardiogram: The key findings are left ventricular hypertrophy. The transaortic valvular gradient can be estimated by Doppler echocardiography. Congestive heart failure was considered to be the cause of death in one-half to two- thirds of patients. Among adults dying with valvular AS sudden death, which
  17. 17. 17 presumably results from an arrhythmia (ventricular tachycardia or fibrillation) occurred in 10 to 20 percent and at an average age of 60 years. TREATMENT: All patients with moderate or severe AS require careful periodic follow-up. In patients with severe AS, strenuous physical activity should be avoided even in the asymptomatic stage. Digitalis glycosides, sodium restriction, and the cautious administration of diuretics are indicated in the treatment of congestive heart failure, but care must be taken to avoid volume depletion. In the majority of adults with calcific AS and critical obstruction, replacement of the valve is necessary. Percutaneous balloon aortic valvuloplasty is an alternative to surgery in children and young adults with congenital aortic stenosis. It is not commonly employed in elderly with severe calcific aortic stenosis because of a high restenosis rate. Electrocardiogram (ECG), left ventricular, and aortic pressure curves in a patient with aortic stenosis. There is a pressure gradient across the aortic valve during systole
  18. 18. 18 Fig. Abnormal sounds and murmurs associated with valvular dysfunction displayed simultaneously with left atrial (LA), left ventricular (LV), and aortic pressure tracings. AVO, aortic valve opening; E, ejection click; MVO, mitral valve opening; OS, opening snap of the mitral valve. . AORTIC REGURGITATION ETIOLOGY: Approximately three-fourths of patients with pure or predominant aortic regurgitation (AR) are males; females predominate among patients with AR who have associated mitral valve disease. Causes: 1- In approximately two-thirds of patients with AR the disease is rheumatic in origin, resulting in thickening, deformation and shortening of the individual aortic valve cusps, changes which prevent their proper opening during systole and closure during diastole. 2- Acute AR also may result from infective endocarditis, which may attack a valve previously affected by rheumatic disease, a congenitally deformed valve, or rarely a normal aortic valve, and perforate or erode one or more of the leaflets. 3- Patients with discrete membranous subaortic stenosis often develop thickening of the aortic valve leaflets, which in turn leads to mild or moderate degrees of AR. 4- AR also may occur in patients with congenital bicuspid aortic valves. 5- Aortic dilatation, i.e., aortic root disease, widening of the aortic annulus and separation of the aortic leaflets are responsible for the AR. 6- Syphilis and ankylosing rheumatoid spondylitis may lead to aortic dilatation, aneurysm formation, and severe regurgitation.
  19. 19. 19 7- Cystic medial necrosis of the ascending aorta, associated with other manifestations of the Marfan syndrome, idiopathic dilatation of the aorta, and severe hypertension all may widen the aortic annulus and lead to progressive AR. 8- Occasionally, AR is caused by retrograde dissection of the aorta involving the aortic annulus. History: Patients with severe AR may remain asymptomatic for 10 to 15 years. Sinus tachycardia during exertion may produce particularly uncomfortable palpitations. Exertional dyspnea is the first symptom of diminished cardiac reserve. This is followed by orthopnea, paroxysmal nocturnal dyspnea, and excessive diaphoresis. Chest pain occurs frequently, even in younger patients, due to diminished coronary filling during diastole. Nocturnal angina may be a particularly troublesome symptom. The anginal episodes can be prolonged and often do not respond satisfactorily to sublingual nitroglycerin. Late in the course of the disease, evidence of systemic fluid accumulation, including congestive hepatomegaly, ankle edema, and ascites, may develop. PHYSICAL FINDINGS: Peripheral signs: Arterial pulse: A rapidly rising “water- hammer” pulse, which collapses suddenly as arterial pressure falls rapidly during late systole and diastole, and capillary pulsations, an alternate flushing and paling of the root of the nail while pressure is applied to the tip of nail, are characteristic of free AR. A booming, “pistol-shot” sound can be heard over the femoral or brachial arteries, and a to - fro murmur is audible if the femoral artery is lightly compressed with a stethoscope. The arterial pulse pressure is widened, with an elevation of the systolic pressure and a depression of the diastolic pressure. The severity of AR does not always correlate directly with the arterial pulse pressure, and severe regurgitation may exist in patients with arterial pressures in the range of 140/60. Palpation: The apex beat is strong and displaced laterally and inferiorly. The systolic expansion and diastolic retraction of the apex are prominent and contrast sharply with the sustained systolic thrust characteristic of severe AS. In many patients with pure AR or with combined AS and AR, palpation or recording of the carotid arterial pulse reveals it to be bisferiens, i.e., with two systolic waves separated by trough.
  20. 20. 20 Auscultation: A third heart sound is common, and occasionally, a fourth heart sound also may be heard. The murmur of AR is typically a high-pitched, blowing, decrescendo early diastolic murmur which is usually heard best in the third left intercostal space. Unless it is trivial in magnitude, the AR is usually accompanied by peripheral signs such as a widened pulse pressure or a collapsing pulse. On the other hand, with the Graham steel murmur of pulmonary regurgitation, there is usually clinical evidence of severe pulmonary hypertension, including a loud and palpable pulmonary component to the second heart sound. A midsystolic ejection murmur is frequently audible in AR. It is generally heard best at the base of the heart and is transmitted to the carotid vessels. This murmur may be quite loud without signifying organic obstruction; it is often higher pitched, shorter, than the ejection systolic murmur heard in patients with predominant AS. A third murmur which is frequently heard in patients with AR is the Austin Flint murmur, a soft, low-pitched, rumbling middiastolic or presystolic bruit. It is probably produced by the displacement of the anterior leaflet of the mitral valve by the aortic regurgitant stream. Both the Austin Flint murmur and the rumbling diastolic murmur of MS are loudest at the apex, but the murmur of MS is usually accompanied by a loud first heart sound and immediately follows the opening snap of the mitral valve, while the Austin Flint murmur is often shorter in duration than the murmur of MS, and in patients with sinus rhythm the latter exhibits presystolic accentuation. Summary: Signs of aortic incompetence over the heart: - Soft blowing early diastolic murmur over aortic area propagated to apex. - Austin-Flint murmur (diastolic murmur over mitral area). Echocardiogram: Essential for detection of severity and cause of AR. TREATMENT: Although operation constitutes the principal treatment of aortic regurgitation, and should be carried out before the development of heart failure, the latter usually respond initially to treatment with digitalis, salt restriction, diuretics, and vasodilators, especially angiotensin-converting enzyme inhibitors.
  21. 21. 21 In patients with severe AR, careful clinical follow-up and noninvasive testing with echocardiography at approximately 6-month intervals are necessary. Operation is to be undertaken at the optimal time, i.e., after the onset of left ventricular dysfunction but prior to the development of severe symptoms. Valve replacement is indicated if the LV dilates to 50 mm in systole and 65 to 70 mm in diastole. ACUTE AORTIC REGURGITATION: Infective endocarditis, aortic dissection, and trauma are the most common causes of severe, acute AR. TRICUSPID STENOSIS It is generally rheumatic in origin and is more common in women than in men. It does not usually occur as an isolated lesion or in patients with pure MR but is usually observed in association with MS. Hemodynamically significant TS occurs in 5 to 10 percent of patients with severe MS; rheumatic TS is commonly associated with some degree of regurgitation. SYMPTOMS: Since the development of MS generally precedes that of TS, many patients initially have symptoms of pulmonary congestion. Amelioration of the latter should raise the possibility that TS may be developing. Fatigue secondary to a low cardiac output and discomfort due to refractory edema, ascites, and marked hepatomegaly are common in patients with TS and / or regurgitation. Severe TS is associated with marked hepatic congestion, often resulting in cirrhosis, jaundice, serious malnutrition, anasarca, and ascites. The jugular veins are distended, and in patients with sinus rhythm there may be giant “a” waves. On auscultation, the pulmonic closure sound is not accentuated, and occasionally, an OS of the tricuspid valve may be heard approximately 0.06 s after pulmonic valve closure. The diastolic murmur of TS has many of the quality of the diastolic murmur of MS, and since TS almost always occurs in the presence of MS, the less common valvular lesion may be missed. The murmur is augmented during inspiration, and it is reduced during expiration. Surgical treatment of the tricuspid valve is not ordinarily indicated at the time of mitral valve surgery in patients with mild TS. On the other hand, definitive surgical relief of the TS should be carried out, preferable a the time of mitral valvotomy, in patients with moderate or severe TS who have mean diastolic pressure gradients
  22. 22. 22 exceeding 4 to 5 mmHg and tricuspid orifices less than 1.5 to 2.0 cm2 . TS is almost always accompanied by significant tricuspid regurgitation. TRICUSPID REGURITATION Most commonly, tricuspid regurgitation (TR) is functional and secondary to marked dilatation of the right ventricle and the tricuspid annulus. Functional TR may complicate right ventricular enlargement of any cause, including inferior wall infarcts that involve the right ventricle, and is commonly seen in the late stages of heart failure due to rheumatic or congenital heart disease with severe pulmonary hypertension, as well as in ischemic heart disease, cardiomyopathy, and cor pulmonale. It is in part reversible if pulmonary hypertension is relieved. Rheumatic fever may produce organic TR, often associated with TS. Endomyocardial fibrosis, infective endocarditis may produce TR. The clinical features of TR result primarily from systemic venous congestion and reduction of cardiac output. The neck veins are distended with prominent V waves, and marked hepatomegaly, ascites, pleural effusions, edema, systolic pulsations of the liver and positive hepato-jugular reflux are common. A prominent right ventricular pulsation along the let parasternal region and a blowing holosystolic murmur along the lower left sternal margin which may be intensified during inspiration and reduced during expiration or the Valsalva maneuver are characteristic findings; AF is usually present. Summary: Signs of tricuspid regurgitation - Pansystolic murmur over tricuspid area increases with inspiration. - Systolic neck vein pulsations Echocardiography and Doppler: for detection of severity of TR, estimation of pulmonary pressure and search for vegetations of infective endocarditis. Treatment of the underlying cause of heart failure usually reduces the severity of functional TR. In patients with mitral valve disease and TR due to pulmonary hypertension and massive RV enlargement, effective surgical correction of the mitral valve abnormality results in lowering of the pulmonary vascular pressure and gradual
  23. 23. 23 reduction or disappearance of the TR. Tricuspid valvuloplasy by De Vega procedure and Carpentier ring can be done. Pulmonary Stenosis: See congenital pulmonary stenosis Pulmonary Regurgitation Dilatation of the pulmonary artery in cases of pulmonary hypertension may produce pulmonary regurgitation. This is called Graham Steel murmur. It is differentiated from the early diastolic murmur of aortic regurgitation by the associated signs of pulmonary hypertension, and by Doppler study. CONGENITAL HEART DISEASE Congenital heart malformations remain one of the most frequent birth defects, with a live-born prevalence of about 8 per 1000 live-born infants in western countries. Etiology of congenital heart disease: It is generally an abnormal form of cardiac development in the first 6-8 weeks of intrauterine life. It is either due to exposure of the fetus in this period to injurious teratogenic factor or to abnormal chromosomal structure. Some causes could be identified as: 1- Drugs e.g. thalidomide, excess alcohol intake, anticonvulsant drugs. 2- Exposure to radiation e.g. X-rays and gamma rays. 3- Hereditary diseases: Diseases caused by chromosomal abnormalities eg Turner syndrome, Down syndrome or mongolism. 4- Maternal infections e.g. German measles in the first trimester of pregnancy. Congenital heart diseases in the adults could be classified into: I- Left or right ventricular outflow obstruction: Aortic stenosis, pulmonary stenosis, coarctation of aorta. II- Left to right shunts: ASD, VSD and PDA. III- Cyanotic heart disease: Fallot’s tetralogy and other cyanotic congenital diseases.
  24. 24. 24 LEET TO RIGHT SHUNT When there is a congenital communication between both sides of the heart, e.g. atrial or ventricular septal defects or patent ductus arteriosus the blood always flows from the left side (left atrium, left ventricle or aorta) to right side (right atrium, right ventricle or pulmonary artery). This is because the pressure in all left-sided chambers is higher than in right-sided chambers. EFFECTS: 1- Left to right shunt results in pulmonary plethora (increased vascularity in the lung). If the shunt is very big heart failure may occur but this is rare. 2- In mild to moderate cases the pulmonary vessels dilate to accommodate the excessive blood flow. Mild cases are well tolerated but if the shunt is excessive the pulmonary vessels react by vasoconstriction. Pulmonary arteriolar vasoconstriction causes pulmonary hypertension which results in right ventricular hypertrophy. 3- Pulmonary hypertension causes rise of pressure in the chambers of the right side of heart. Ultimately the pressure in the right side exceeds that of the left side and the blood starts to flow across the defect in the reverse direction, i.e. right to left shunt (reversed shunt). The patient becomes cyanosed. Emboli originating in the venous side may be shunted across the defect to the arterial side and settle in organs such as the brain or limbs. This is paradoxical embolism. Closure of the defect at this stage is useless and dangerous. This situation of a congenital defect + reversed shunt is called Eisenmenger’s syndrome. Eisenmenger’s syndrome is not an independent congenital heart disease. It is the end result of big left to right shunt. At this stage the clinical picture is that of central cyanosis with severe pulmonary hypertension. ATRIAL SEPTAL DEFECT In the presence of a defect in the atrial septum the right atrium receives blood both from the normal venous return and the left atrium, the right atrium dilates. This results in: Dilatation and hypertrophy of the right ventricle (volume overload), dilatation of the pulmonary artery, and pulmonary plethora. If the defect is big and uncorrected pulmonary arteriolar vasoconstriction progressively occurs and results in pulmonary hypertension usually at age 20-30 years. When the pressure in the right atrium exceeds
  25. 25. 25 that in the atrium the shunt becomes reversed (Eisenmenger’s syndrome) and the patient becomes cyanosed. Clinical features: 1- Atrial septal defect is more common in females. When the left to right shunt is very big pulmonary plethora may predispose to repeated chest infections in infancy. Otherwise there are no symptoms for many years. Ultimately heart failure occurs. 2- Atrial fibrillation occurs in late cases. 3- Right ventricular dilatation and hypertrophy cause a hyperdynamic impulse in the third and fourth spaces to the left of the sternum and precordial bulge. 4- Excessive flow across the tricuspid valve may produce a third heart sound and short mid-diastolic murmur at the tricuspid area. 5- Excessive blood flow at the pulmonary valve may produce pulsations, dullness and an ejection systolic murmur in the pulmonary area. 6- The specific auscultatory sign of atrial septal defect is wide fixed splitting of the second heart at the pulmonary area. The pulmonary component of the second sound is delayed because the right ventricle takes a long time o empty the excessive volume of blood it receives. The splitting dose not vary with respiration because: although inspiration causes increase in venous return, yet the resulting rise in right a trial pressure causes proportionate decrease in the left to right shunt so that the right ventricular output is constant and the time relation between aortic and pulmonary components of the second sound remains constant. 7- Progressive pulmonary hypertension occurs in big defects and result in Eisenmenger syndrome. At this stage the clinical picture consists of: Central cyanosis, signs of pulmonary hypertension, and signs or right ventricular hypertrophy. X-RAY PICTURE: 1- Plethoric lung fields. 2- Dilatation of the right atrium, right ventricle and pulmonary artery. 3- Marked pulsation of the pulmonary artery and its branches seen during screening (hilar dance). ELECTROCARDIOGRAPHIC FEATURES: The characteristic sign is incomplete right bundle branch block with rSr' pattern in V1 lead. Signs of right ventricular hypertrophy also appear when pulmonary hypertension develops. Atrial fibrillation occurs in late cases. ECHOCARDIOGRAPHY WITH DOPPLER: Must be done for every patient with suspected congenital heart disease. In A.S.D. it shows the septal defect and dilated right
  26. 26. 26 ventricle and abnormal movement of the interventricular septum characteristic of volume overload on the right ventricle. Cardiac catheterization may be done in some cases. COMPLICATIONS: 1- Pulmonary hypertension and reversal of shunt. 2- Right ventricular failure. 3- A trial fibrillation. TREATMENT: Small defects can be left alone. Large defects should be closed surgically or by percutaneous insertion of occluder (device that occludes the ASD) . VENTRICULAR SEPTAL DEFECT 1- In the presence of a defect in the septum, the right ventricle receives both the normal venous and the shunted blood. If the defect is big right ventricular hypertrophy occurs. 2- This excessive blood flows in the pulmonary artery and the pulmonary circulation and then returns to the left atrium and the left ventricle. This causes: Dilatation of the pulmonary artery, pulmonary plethora, dilatation of the left atrium, dilatation and hypertrophy of the left ventricle. 3- If the shunt is very big excessive flow may cause heart failure in infancy. 4- If the shunt is large the pulmonary vessels react by vasoconstriction causing pulmonary hypertension and reversal of shunt (Eisenmenger syndrome). 5- Small V.S.D. does not cause pulmonary hypertension and may close spontaneously. Clinically, the murmur is very loud (Roger’s disease). CLINICAL PICTURE: The specific signs of V.S.D. are: 1- A characteristic pansystolic murmur best heart in the third and fourth left intercostal spaces just lateral to the sternum, usually accompanied by a thrill. 2- With large shunts the increased flow across the mitral valve may cause a third sound and a mid-diastolic flow murmur at the apex. The clinical course depends upon the size of the defect: 1- Small ventricular septal defect: many defects close spontaneously. 2- Moderately large defect:
  27. 27. 27 1st- Progressive pulmonary hypertension and low cardiac output e.g. fatigue, syncope on exercise, pulsations and palpable loud second heart sound in the pulmonary area, right ventricular hypertrophy, etc. 2nd- When the pressure in the right ventricle equals that in the left ventricle no blood will flow across the defect and the murmur diminishes disappears. The patient becomes cyanosed on crying. 3rd- When the shunt is reversed the patient becomes cyanosed. X-RAY PICTURE: Is normal in cases with small defects. Large defects result in: pulmonary plethora (overfilled large and tortuous pulmonary arteries), large main pulmonary artery, left and right ventricular enlargement, left atrial enlargement. ECHOCARDIOGRAPHY WITH DOPPLER: Can show the size of cardiac chambers. The defect can sometimes be shown by two-dimensional echo. Color Doppler is very helpful in showing the blood flow through the defect. Detection of the site of the defect, the magnitude of the shunt and the degree of pulmonary hypertension can be assessed by this non-invasive method. CARDIAC CATHETERISATION AND ANGIOGRAPHY: Is done in some cases. COMPLICATIONS: Infective endocarditis, pulmonary hypertension, and heart failure. DIFFERENTIAL DIAGNOSIS: A pansystolic murmur at the sternal border can be caused by tricuspid or mitral incompetence in addition to the ventricular septal defect. Sometimes the murmur of pulmonary stenosis is heard at the third intercostal space but it is usually ejection in type and its maximal intensity is in the second space. Other causes of systolic murmur at left sternal border are hypertrophic obstructive cardiomyopathy, subaortic membrane and aortic stenosis. TREATMENT: 1- To prevent infective endocarditis all patients must receive an antibiotic prophylaxis before performing minor procedures that may causes bacteremia, e.g. dental extraction, delivery, etc. 2- Small ventricular septal defects should be left alone. Many of them close spontaneously. 3- Surgical closure is indicated if the defect is moderate or large in size, provided that the pulmonary pressure is normal or moderately elevated. Surgical closure is contraindicated if pulmonary pressure is severe (Eisenmenger’s syndrome). PATENT DUCTUS ARTERIOSUS
  28. 28. 28 The ductus arteriosus is normally present in the fetus. It connects the aorta (at the junction of the arch with the descending aorta) with the pulmonary artery (at the junction of the main pulmonary artery with its left branch). It normally closes. During the first month after birth: Effects: 1- The blood flows through the duct from the aorta to the pulmonary artery, i.e. left to right shunt. 2- As the pulmonary artery receives blood both from the shunt and the right ventricle, pulmonary artery dilatation and pulmonary plethora occur. 3- If the shunt is big pulmonary vasoconstriction and hypertension occurs. When the pressure in the pulmonary artery equals that of the aorta the shunt will first become confined to the systole only and then ceases altogether. The murmur, accordingly, will first become only systolic and finally will be completely inaudible. 5- When the pressure in the pulmonary artery exceeds that of the aorta, the shunt will be reversed and cyanosis occurs (Eisenmenger’s syndrome). CLINICAL FEATURES: Patent ductus arteriosus is commoner in females. Its characteristic signs are: 1- A continuous (machinery) murmur that occupies both systole and diastole because the pressure in the aorta exceeds that of the pulmonary artery all through the cardiac cycle. It is best heard in the first and second left intercostal spaces. There may be continuous thrill in the same area. 2- With large ductus, the increased flow across the mitral may cause a mid-diastolic murmur. When the pressure in the pulmonary artery exceeds that of the aorta, right to left shunt occurs and cyanosis appears (Eisenmenger’s syndrome). The deoxygenated blood will flow from the pulmonary artery across the ductus down the descending aorta. The lower limbs will be cyanosed while the upper limbs remain pink (differential cyanosis). X-RAY PICTURE: X-ray is normal in cases with small ductus. In moderate to large ductus the following signs appear: Pulmonary plethora, enlargement of the left atrium, left ventricle and the aorta. Hilar dance seen in the hilum by screening. Differential diagnosis: Other causes of continuous murmur as aorto-pulmonary window, in coarctation of the aorta, mammary softle, rupture sinus of Valsalva, venous hum...
  29. 29. 29 TREATMENT: Prophylaxis against endocarditis. Closure either surgical or with a device introduced with percutaneous, transvenous catheter. CYANOTIC HEART DISEASE - Tetralogy of Fallot. - Ebstein anomaly. - Transposition of the great arteries. - Total anomalous pulmonary venous drainage. - Truncus arteriosus. - Pulmonary arterio-venous malformation. Acquired cyanotic disease: Eisenmenger Syndrome. FALLOT’S TETRALOGY PATHOLOGY AND EFFECTS: Fallot’s tetralogy consists of: 1- Severe pulmonary stenosis which causes right ventricular hypertrophy. The pulmonary stenosis is usually infundibular but sometimes it is both valvular and infundibular.
  30. 30. 30 2- Large ventricular septal defect which makes the pressure equal in both ventricles. 3- The origin of the aorta is abnormally deviated to the right (dextroposed, dextro = right) so that it lies partly over the right ventricle (the aorta overrides both ventricles). 4- Due to the severe pulmonary stenosis and the large ventricular septal defect, the pressure in both ventricles is equal. There is rush of blood across the defect and the ventricular septal defect produces no murmur. 5- Part of the blood pumped by the right ventricle passes in the aorta (right to left shunt) causing central cyanosis. In summary Fallot’s tetralogy consists of four components (tetra =4). 1- Pulmonary stenosis. 2- Ventricular septal defect. 3- Dextroposed and overriding aorta. 4- Right ventricular hypertrophy. CLINICAL FEATURES: 1- The patient is cyanosed since birth, (usually after birth by few weeks); the degree of cyanosis depends on the severity of the pulmonary stenosis. 2- When the patient exercises, cyanosis is increased. In order to increase the blood flow to the head and brain, the child usually squats to compress the lower limbs against the abdomen and to deviate the blood from the lower to the upper half of the body. It also increases the systemic arterial resistance. As the pressure in the aorta rises, more blood will be deviated across the pulmonary stenosis to the lungs. Thus more oxygenated blood returns to the heart. 3- Chronic cyanosis and tissue anoxia results in: Dyspnea, fatigue, angina, retarded growth, polycythemia, clubbing of fingers. 4- Sometimes the muscle surrounding the outflow tract of the right ventricle goes into spasm, especially after excitement and exercise. The blood flow to the lungs decreases markedly and the oxygenation decreases resulting in attacks of severe cyanosis: cyanotic spells. If prolonged they may lead to death. 5- The characteristic cardiac signs are: A- Murmur of pulmonary stenosis (ejection systolic murmur in second left space, usually accompanied by a thrill.
  31. 31. 31 B- The second heart sound is single and consists only of the aortic component. C- Right ventricular hypertrophy. X-RAY PICTURE: 4. Right ventricular hypertrophy causes the apex to be displaced outwards and becomes separated from the diaphragm. 5. Right-sided aortic arch in some cases. 6. Pulmonary oligemia (the pulmonary artery and its branches are diminished in size due to the pulmonary stenosis. All the above factors result in a characteristic cardiac shadow: Coeur en sabot (sabot = wooden shoe). ELECTROACARDIOGRAPHIC FEATURES: Show moderate right ventricular hypertrophy. ECHOCARDIOGRAPHY WITH DOPPLER: Delineates the abnormal anatomy. Cardiac catheterization and angiography is needed for differential diagnosis. COMPLICATIONS: 1- Polycythemia causes increased viscosity of blood resulting in a tendency towards thrombosis, e.g. cerebral thrombosis. 2- Infective endocarditis 3- Brain abscess results when bacterial emboli are shunted from the venous to the arterial side and lodge in the brain (paradoxical embolism). TREATMENT: 1- Surgical correction is indicated in all cases by: Resection of the excessive stenotic infundibular muscle splitting of the fused pulmonary valve leaflets, and closure of the ventricular septal defect. 2- If he patient is too young, or the condition is too severe, an anastomosis is performed to allow blood to reach the lungs by: implanting the subclavian artery in the corresponding pulmonary artery (Blalock-Taussig operation). 3- Cyanotic attacks result from infundibular spasm and constitute an emergency. The are treated by: Put the patient in the squatting position or compress the flexed lower limbs against the abdomen, sedation, propranolol (inderal) intravenously. Propranolol is a beta-adrenergic blocker. It depresses the contractility of the infundibular muscle. LEFT VENTRICULAR OUTFLOW TRACT OBSTRUCTION - Valvular aortic stenosis: 70% of patients with valvular AS a malformation of the valve (usually a bicuspid valve).
  32. 32. 32 - Discrete subvalvular aortic membrane: Represents 8-10% of congenital AS. The magnitude of obstruction is variable. Most membranes are eventually associated with progressive aortic regurgitation and their presence may be an absolute indication for excision. There is a high recurrence rate after excision (approximately 30% and septal myotomy is often performed). COARCTATION OF THE AORTA Narrowing of the aorta usually just distal to the left subclavian artery. Coarctation may affect other parts of the aorta or the renal arteries. EFFECTS: 1- Because of the narrowing, pressure rises in the ascending aorta and the aortic arch and its branches. This results in hypertension in the upper limbs. 2- Pressure and flow decreases in the descending aorta and its branches producing ischemia in the abdominal organs and the limbs. 3- Ischemia of the kidneys results in release of renin which raises the blood pressure. 4- Hypertension results in left ventricular hypertrophy and it severe results in left ventricular failure. 5- Anastomosis form between the branches of the aorta proximal and distal to the obstruction. The most important of these connect the subclavian artery through its internal mammary branch to the intercostal arteries which arise from descending aorta. The intercostal arteries become enlarged and tortuous and erode the lower border of the ribs causing rib notching. Appreciable anastomosis develops gradually by time. That is why rib notching is not detectable except after the age of 10. Other anastomosis develops around the scapula and another connects the superior and inferior epigastric arteries. CLINICAL FEATURES: 1- In the majority of cases there are no symptoms and the essential diagnostic feature of coarctation is that the blood pressure in the upper limbs exceeds that in the lower limbs. 2- The pulse in the upper limbs, neck and suprasternal notch is strong. Pulse in the lower limbs is weak and delayed or absent.
  33. 33. 33 3- Hypertension in the upper half of the body may produce headache, epistaxis while ischemia of the lower half may produce thin, underdeveloped lower limbs and claudication in the calf. 4- Visible and palpable pulsations of dilated collateral may be felt in the intercostal areas. 5- A late systolic murmur may be heard on the back due to blood flow in the collaterals. The murmur is sometimes continuous. 6- The cardiac signs are nonspecific and include: left ventricular hypertrophy, an ejection systolic murmur heard at the aortic area. X-RAY PICTURE: 1- Signs of left ventricular hypertrophy. 2- Rib notching is the most specific sign. ELECTROCARDIOGRAPHIC SIGNS: Left ventricular hypertrophy and strain. COMPLICATIONS: 1- Hypertension in the upper half of the body may result in: cerebral or subarachnoid hemorrhage, left ventricular failure, dissection of the aorta. 2- Infective endocarditis. TREATMENT: surgical resection of the narrowed segment is indicated in moderate and severe cases preferably during childhood. Balloon dilation with expandable stent is a feasible method of treatment. All patients must have prophylaxis against endocarditis. PULMONARY STENOSIS Pulmonary stenosis may be caused by: Congenital fusion of pulmonary valve cusps (congenital valvular pulmonary stenosis). EFFECTS: 1- In both valvular and infundibular stenosis the pressure in the right ventricle rises, this causes hypertrophy of the right ventricle (pressure over-load). Consequently the right atrium hypertrophies. When the stenosis is severe the output of the right ventricle and the cardiac output are reduced. The pulmonary blood flow is reduced, i.e. pulmonary oligemia. CLINICAL FEATURES:
  34. 34. 34 1. Mild cases are as asymptomatic, in severe cases low cardiac output occurs and results in fatigability, syncope on effort, small volume pulse, cold extremities, etc. 2. An ejection systolic murmur is caused by passage of blood through the stenosed valve. It is best heard over the pulmonary area. It may be preceded by an ejection click. 3. The pulmonary component of the second heart sound is faint and delayed due to prolonged contraction of the right ventricle. 4. There is usually a systolic thrill over the pulmonary area. 5. Right ventricular hypertrophy produces a sustained impulse in the third and fourth intercostal spaces just to the left of the sternum and pulsation in the epigastrium. Forceful right atrial contraction causes a large wave in the neck veins (the a wave). X-RAY PICTURE: 1. Pulmonary oligemia occurs in moderate to severe cases and results in reduced pulmonary vascular markings). 2- Right ventricular enlargement is proportional to the severity of the stenosis. Right atrial enlargement may also occur. 3. Post-stenosis dilatation of the pulmonary artery is seen. ECG FEATURES: Right ventricular hypertrophy. ECHO FEATURES: Right ventricular hypertrophy, the stenosed pulmonary valve. TREATMENT: Either percutaneous transvenous balloon dilatation (the standard treatment, first option) or surgical removal of the valve by open-heart surgery. Interventions In Congenital Heart Diseases (therapeutic procedures that are used in treatment without surgery but through catheterization): - Pulmonary stenosis balloon dilatation. - Aortic stenosis balloon dilatation. - Coarctation of the aorta balloon dilatation and stent insertion. - Atrial septal defect insertion of Amplatzer occluder through catheter. - Patent ductus arteriosus occlusion by insertion of coil. - Other procedures. DIAGNOSIS AND MANAGEMENT OF SYNCOPE AND HYPOTENSION
  35. 35. 35 Syncope is a sudden and transient loss of consciousness with associated loss of postural tone. The occurrence of syncope is 3% in men ad 3.5% in women in the general population. As a general role, the incidence of syncope increases with age. Hypotension: When systolic blood pressure (SBP) is less than 90 mmHg or reduction of SBP of 30 mmHg or more from baseline. Patients with transient episode of altered consciousness (presyncope) and those with complete loss of consciousness (syncope) are classified into 3 broad categories: cardiac syncope, noncardiac syncope, and syncope of undetermined etiology. Among all patients with syncope associated with cardiac disease, sudden cardiac death is extremely high. Table: Causes of Syncope Circulatory (reduced cerebral blood flow) A. Inadequate vasoconstrictor mechanisms 1. Vasovagal (vasodepressor) 2. Postural hypotension 3. Primary autonomic insufficiency 4. Sympathectomy (pharmacologic, due to antihypertensive medications such as methyldopa and hydralazine, or surgical ) 5. Carotid sinus syncope 6. Diseases of the central and peripheral nervous system, including autonomic nerves) B. Hypovolemia 1. Blood loss – gastrointestinal hemorrhage. 2. Addison’s disease C. Mechanical reduction of venous return 1. Valsalva maneuver. 2. Cough; Micturition. 3. Atrial myxoma, ball valve thrombus. D. Reduced cardiac output 1. Obstruction to left ventricular outflow: aortic stenosis, hypertrophic subaortic stenosis. 2. Obstruction to pulmonary flow: pulmonary stenosis, primary pulmonary hypertension, pulmonary embolism. 3. Myocardial: massive myocardial infarction with pump failure. 4. Pericardial: cardiac tamponade E. Arrhythmias
  36. 36. 36 1. Bradyarrhythmias a. Atrioventricular (AV) block (second and third degree), with Stokes-Adams attacks b. Ventricular asystole c. Sinus bradycardia, sinoatrial block, sinus arrest, sick sinus syndrome d. Carotid sinus syncope a. Tachyarrhythmias: Supraventricular tachycardia. Episodic ventricular tachycardia Other causes of disturbances of consciousness A. Hypoglycemia B. Hypoxia C. Hypoventilation D. Transient cerebral ischemic attack E. Emotional disturbances, anxiety attack, hysterical seizures. Noncardiac Syncope Neurocardiogenic syncope: The syndrome of neurocardiogenic syncope, the common faint (also referred to as neurally mediated hypotension, vasovagal syncope, and vasodepressor syncope), is one of the most common causes of syncope. This disorder is due to abnormality in the neuro-cardiovascular interactions responsible for maintaining systemic and cerebral perfusion. Diagnostic evaluation: Head-up tilt (HUT) is essential for the diagnosis of neurocardiogenic syncope. Here we change the position of the patient from the horizontal to the vertical position. HUT at an angle of 60º to 90º for a time period of 20 to 60 min is the usual protocol. Management of syncope: First-line therapy includes counseling the patient to avoid dehydration, prolonged period of standing motionless, and situations known to trigger syncope. Volume expansion, fludrocortisone may be helpful in augmenting salt retention and volume expansion. Alpha-Agonists: Medodrine may prevent neurocardiogenic syncope due to vasoconstrictor effect that may reduce venous pooling. Orthostatic Syncope (orthostatic Hypotension): Orthostatic hypotension is a disorder in which assumption of the upright posture is associated with a fall in blood pressure. Therapy: is based on treatment of causes.
  37. 37. 37 Management of hypotension: 1- Treatment of the etiology. 2- Avoid dehydration. 3- Medodrine. 4. Mineralocorticoids as Astonin H. Cardiac Syncope It is due to severe diminution of the cardiac output Either due to severe obstructive lesion as tight mitral stenosis, atrial myxoma, aortic stenosis, obstructive cardiomyopathy or due to arrhythmia whether tachy or brady. Obstructive lesions and arrhythmias frequently coexist; indeed, one abnormality may accentuate the other. Common disorders associated with cardiac syncope are listed in table. Diagnostic evaluation of syncope associated with cardiac disease: - History & physical examination - Echocardiography & Doppler - Standard ECG - Holter monitor ( 24 h. ECG continuous recording ) - Electrophysiologic study. - Cardiac catheterization. Treatment of cardiac syncope: Obstructive Heart Disease, for patients with syncope caused by obstructive heart disease, cardiac surgery is often the treatment of choice. Arrhythmic syncope, detailed discussion of therapy for cardiac arrhythmias presented earlier. Antiarrhythmic drugs, pacemakers and ablation are available tools of management of arrhythmia. Syncope of undetermined cause: Despite careful diagnostic evaluation, the cause of syncope often cannot be defined. Sudden Cardiac Death Definition: Sudden cardiac death describes the unexpected natural death due to cardiac cause within a short period from the onset of symptoms. More recent definition focused on time interval of one hour from the symptoms leading to collapse and then to death. Incidence: SCD accounts for 300.000 to 400.000 deaths yearly in the United States. SCD is the most common and often the first manifestation of coronary heart disease (CHD) and is responsible for half the deaths from cardiovascular disease.
  38. 38. 38 Sudden Cardiac Death in the young: The most common underlying pathological conditions in people who die of SCD in the first three decades of life are myocarditis, hypertrophic cardiomyopathy, congenital coronary artery anomalies, atherosclerotic coronary heart disease, conduction system abnormalities (e.g. long QT), congenital arrhythmogenic disorders, arrhythmias associated with mitral valve prolapse and aortic dissection. About 40% of SCD in the pediatric population occur in patients with surgically treated congenital cardiac abnormalities. Risk factors for Sudden Cardiac Death (SCD): 1- Left ventricular hypertrophy (by ECG) 2- Cholesterol. 3- Hypertension. 4- Cigarette smoking. 5- Diabetes. 6- Alcohol. 7- Obesity. 8- History of coronary heart disease. 9- Age. 10- Positive family history of SCD. 11- Frequent PVCs (Premature ventricular contractions, unsustained ventricular tachycardia). Cardiac Abnormalities Associated with Sudden Cardiac Death I. Ischemic heart disease A) Coronary Atherosclerosis: - Acute myocardial infarction, - Chronic ischemic cardiomyopathy B) Anomalous origin of coronary arteries. II. Cardiomyopathies A. Idiopathic dilated cardiomyopathy B. Hypertrophic cardiomyopathy C. Hypertensive cardiomyopathy D. Arrhythmogenic right ventricular dysplasia III. Valvular heart disease: Aortic stenosis IV. Inflammatory and Infiltrative myocardial disease
  39. 39. 39 V. Congenital heart disease. VI. Primary Electrical Abnormality. A. Long Q-T syndrome B. Wolf Parkinson White syndrome (WPW). C. Idiopathic ventricular tachycardia D. Idiopathic ventricular fibrillation E. Brugada syndrome (right bundle block with raised ST in V1 to V3) VII. Drug and other toxic agents A. Proarrhythmia (Drug induced arrhythmia) B. Cocaine and Alcohol. C. Electrolyte abnormalities Treatment Options for Patients at Risk of Sudden Cardiac Death (SCD) I. Pharmacologic therapy 1- Beta blockers , Angiotensin-converting enzyme inhibitors 2- Class I antiarrhythmic drugs, 3- Class III antiarrhythmic drugs: Amiodarone, sotalol II. Device therapy 1- Automatic implantable cardioverter Defibrillator (ICD) 2- External automatic defibrillator III. Role of surgery: Revascularization IV. Catheter Ablation therapy.
  40. 40. 40 CARDIAC ARRHYTHMIAS An arrhythmia is any disturbance in the normal sequence of impulse generation and conduction in the heart. Anatomy of the conduction system: The conduction system of the heart consists of the sinus node, internodal tracts, atrioventricular node (AVN), bundle of His, bundle branches (right and left), and Purkinje fibers. Fig: The pathways of Conduction. General considerations: Normal cardiac impulses arise from the automatic (pacemaking) cells of the sinus node and are conducted through the atria to the AV junction then the His-Purkinje system to the ventricular muscle. Normally the sinus node discharges at a rate of 60-100/min.
  41. 41. 41 Mechanisms of arrhythmias A- Disturbance of impulse formation: may result from either: 1- Disturbed normal automaticity: 2- Triggered activity: Hyper-excitable focus which discharges ectopic impulses. B- Disturbance of Impulse conduction: e.g. heart block Classification of arrhythmia: Clinical classification: - Rapid, regular. Sinus tachycardia, supraventricular tachycardia, atrial flutter, ventricular tachycardia. - Rapid, irregular. Sinus arrhythmia, multiple ectopic beats whether atrial or ventricular, atrial fibrillation. - Slow, regular. Sinus bradycardia, nodal rhythm, complete heart block. - Slow, irregular. Slow atrial fibrillation. Disturbances in Sinus Rhythm Sinus tachycardia Cardiac impulses arise in the sinus node at a rate more than 100/min. Etiology: A- Physiological: Infancy, childhood, exercise and excitement. B- Pharmacological: Sympathomimetic drugs such as epinephrine and isoproterenol. Parasympatholytic drugs such as atropine. Thyroid hormones, nicotine, caffeine, alcohol. C- Pathological: Fever, hypotension, heart failure, pulmonary embolism, hyperkinetic circulatory states as anemia. Treatment: 1- Treatment of the underlying etiology. 2- Propranolol. Sinus Bradycardia Cardiac impulses arise in the sinus node at a rate less than 60/min. Etiology: A- Physiologic: Athletes, sleep, and carotid sinus compression. B- Pharmacologic: Digitalis, propranolol, verapamil and diltiazem. C- Pathologic: Convalescence from infections, hypothyroidism, obstructive jaundice, rapid rise of the intracranial tension, hypothermia and myocardial infarction (particularly inferior wall infarction).
  42. 42. 42 Treatment: 1- Treatment of the underlying etiology is usually all that is needed. 2- If the patient is hemodynamically compromised, Atropine 0.6 – 1.0 mg IV may be given and repeated every 3 hours (maximum 2.5 mg in two hours). SICK SINUS SYNDROME: This term is applied to a syndrome encompassing a number of sinus nodal abnormalities that include: 1- persistent spontaneous sinus bradycardia not caused by drugs, and inappropriate for the physiological circumstance, 2- apparent sinus arrest or exit block, 3- combinations of SA and AV conduction disturbances, or 4- alternation of paroxysms of rapid and slow atrial and ventricular rates (bradycardia-tachycardia syndrome). FIG. Normal intracardiac electrograms. PREMATURE BEATS (EXTRASYSTOLES) These are cardiac impulses of ectopic origin occurring earlier than expected in the prevailing rhythm. The ectopic focus may be: 1- Atrial resulting in atrial premature beat. 2- AV junctional (arising from bundle of His) resulting in AV junctional premature beat. 3- Ventricular resulting in ventricular premature beat.
  43. 43. 43 Etiology: A- Physiological: Emotions, exercise and fatigue. B- Pharmacological: Coffee, alcohol, tobacco, catecholamines, digitalis and hypoxia. C- Pathological: Various infections, digestive disturbances, hyperthyroidism and all cardiovascular disorders. SUPRAVENTRICULAR TACHYARRHYTHMIAS All tachyarrhythmias that originate above the bifurcation of the bundle of His are classified as supraventricular arrhythmias (SVT). The atrial rate must be 100 or more beats per minute for a diagnosis. SVTs may be separated into three groups based on duration: brief paroxysms, persistent, and chronic (permanent). Arrhythmias that are paroxysmal in onset and offset (e.g., paroxysmal SVT due to AV nodal reentry or WPW syndrome, paroxysmal atrial fibrillation, paroxysmal atrial flutter) tend to be recurrent and of short duration; i.e., seconds to hours. Persistent tachycardias (e.g., sinus tachycardia, ectopic atrial tachycardia (nonparoxysmal), multifocal atrial tachycardia, longer episodes of PSVT or atrial flutter or fibrillation) may persist for days or weeks. Longstanding or chronic SVTs (chronic atrial flutter, chronic atrial fibrillation) do not revert if untreated, often fail to revert even with attempted treatment, and if reverted will frequently recur despite therapy. Supraventricular tachyarrhythmias include; atrial tachycardia, atrial flutter, atrial fibrillation and AV tachycardias. ATRIAL FLUTTER Atrial flutter is a rapid regular atrial tachyarrhythmia that is less common than the PSVTs or atrial fibrillation. It is observed in the presence of underlying atrial abnormalities such as those secondary to mitral valve disease, congenital heart disease, cardiomyopathies, and, less frequently, coronary artery disease.
  44. 44. 44 Untreated atrial flutter usually has atrial rates between 240 and 340 per minute, commonly very close to 300 per minute. The ventricular rate in atrial flutter is usually a defined fraction of the atrial rate 2: 1 conduction generating a ventricular rate of 150 per minute and 4:1 conduction at 75 per minute. Clinically, atrial flutter may occur in brief, persistent, or chronic forms, and therapeutic approaches are influenced by the clinical pattern. Electrocardiographic Features Atrial flutter generates a defined pattern of atrial activity in the ECG. Classically, a saw- tooth pattern is identifiable in leads II, 111, and aVF. A narrow QRS complex tachycardia at a rate of 150 per minute should always lead to the consideration of atrial flutter. Carotid sinus massage will not interrupt atrial flutter but nonetheless may be very helpful in distinguishing flutter from other mechanisms, impairment of AV nodal conduction causes an abrupt change from a rate of 150 per minute to 75 per minute or less. Management of atrial flutter: - If the patient is hemodynamically compromised, D.C. cardioversion using low energies (around 50 joules) should be instituted. - Administering a Class IA antiarrhythmic agent (i.e., quinidine, procainamide, or disopyramide). IC antiarrhythmic drugs, flecainide and propafenone, are as effective, if not more effective than Class IA drugs. Class III antiarrhythmic agents (i.e., amiodarone, sotalol) may also be quite effective. In general, atrial flutter is difficult to suppress completely with drug therapy. - The ventricular rate is slowed by digitalis and/or propranolol or verapamil before antiarrhythmics are instituted to avoid very rapid rates associated with drug induced 1:1 AV conduction. - At present, catheter ablation provides the best hope of cure. FIG. A 12-lead ECG of a typical case of type 1 atrial flutter.
  45. 45. 45 FIG. A 12-lead ECG of a typical case of type 1 atrial flutter. FIG: Atrial flutter with AV block varying between 2: 1 and 4: 1. AV Nodal Reentrant Tachycardia Electrocardiographic Features: Paroxysmal SVT due to AV nodal reentry is characterized by an abrupt onset and termination and usually has a narrow QRS complex without clearly discernable P waves. The rate is commonly in the range of 150 to 250 per minute (commonly 180 to 200 bpm in adults) and with a regular rhythm. Management of PSVT Due to AV Nodal Reentry The acute attack: Vagal maneuvers serve as the first line of therapy. Simple procedures to terminate paroxysmal SVT - Carotid sinus massage: If effective the rhythm is abruptly stopped; occasionally only moderate slowing occurs - Cold water splash on face. - Performance of Valsalva's maneuver (often effective).
  46. 46. 46 Intravenous adenosine, Ca channel blockers (verapamil), digoxin or B-blockers are the choices for managing the acute episodes. Adenosine, 6 mg given intravenously, followed by one or two 6-mg boluses if necessary, is effective and safe for acute treatment. A 5-mg bolus of verapamil (isoptin) , followed by one or two additional 5-mg boluses 10 min apart if the initial dose does not convert the arrhythmia, has been an effective regimen in up to 90 percent of patients with PSVT due to AV node reentry. Intravenous digoxin, 0.5 mg infused over 10 min and repeated if necessary may convert the arrhythmia. DC cardioversion: Consider DC cardioversion before digitalis or a beta blocker is administered. Radiofrequency catheter ablation: Should be considered early in the management of patients with symptomatic recurrent episodes of AV node reentry. AV Reentrant Tachycardia PSVT Due to Accessory Pathways (The Wolff-Parkinson-White Syndrome)
  47. 47. 47 ELECTROCARDIOGRAPHIC RECOGNITION: Three basic features in the ECG of patients with the usual form of WPW syndrome caused by an AV connection: (1) Short P-R interval less than 120 msec during sinus rhythm; (2) QRS complex duration exceeding 120 msec (3) Slowly rising onset of the QRS in some leads (delta wave). The most common tachycardia is characterized by a normal QRS, by ventricular rates of 150 to 250 beats/min and by sudden onset and termination. Termination of the acute episode should be approached as for AV nodal reentry. In many patients, particularly those with a very rapid ventricular response, electrical cardioversion is the initial treatment of choice. The Wolff-Parkinson-White Syndrome ELECTRICAL ABLATION: Ablation of the accessory pathway is advisable for patients with frequent symptomatic arrhythmias that are not fully controlled by drugs. Atrial Fibrillation
  48. 48. 48 The arrhythmia is characterized by multiple electric foci in the atrium causing disorganized atrial depolarizations without effective atrial contraction. Electrical activity of the atrium can be detected on ECG as small irregular baseline undulations, called f waves, at a rate of 350 to 600 beats/min. The ventricular response is grossly irregular (irregular irregularity) and is usually between 100 and 160 beats/min. It is a common arrhythmia, occurring in 5 – 10 % of individuals over 65 years of age. It also occurs in a paroxysmal form in younger patients. The hemodynamic consequences of atrial fibrillation are due to two factors: (1) The loss of atrial systole may impair ventricular function in the noncompliant ventricle [e.g., aortic stenosis, left ventricular hypertrophy (LVH)] or the dilated ventricle with systolic dysfunction, and (2) A rapid ventricular rate will encroach upon the diastolic filling period of the left ventricle and the diastolic flow time of the coronary arteries. (3) The risk of embolism and stroke is a long-term concern of special importance. Atrial fibrillation may occur in paroxysmal, persistent, and chronic patterns. Clinical expression of atrial fibrillation: Definition Duration - Paroxysmal Minutes/hours - Short-lasting Seconds --<1 hour - Long-lasting >1 hour; -- < 48 hours - Persistent Two days -- weeks - Permanent (Chronic) Months / years Table: Causes of atrial fibrillation With structural heart disease - Rheumatic mitral valve disease - Ischemic heart disease - Hypertension - Cardiomyopathy: Dilated, Hypertrophic - Atrial septal defect, - Constrictive pericarditis, Myocarditis Without structural heart disease
  49. 49. 49 - Alcohol. Thyrotoxicosis - Acute pericarditis. Pulmonary embolism - Sick sinus syndrome, Lone atrial fibrillation Atrial Fibrillation Clinical picture Onset and offset are sudden in paroxysmal cases. Symptoms: Paroxysmal AF produces symptoms similar to those of supraventricular tachycardia. Established AF (persisting for more than two weeks) is better tolerated than the paroxysmal variety. Congestive heart failure may occur if the attack is prolonged, the ventricular rate is very rapid, or the underlying heart disease is severe. Signs: 1- Arterial pulse: a- Rate is usually 100-150/min. Slower rates may be encountered in old age and in patients receiving digitalis or beta-blockers.
  50. 50. 50 b- Rhythm shows marked (irregular) irregularity. c- Force is irregular. d- Pulsus deficit: The radial pulse rate is less than the cardiac rate counted at the apex beat. This is due to inability of the week ventricular contractions following short diastolic periods to open the aortic valve. 2- Neck veins show systolic expansion; no “a” waves are seen. 3- Auscultation reveals varying intensity of S1. 4- Exercise increases the pulse irregularity and deficit. Electrocardiogram: The P waves are replaced by irregular f waves. The QRS complexes are normal in shape but irregularly spaced. Complications: 1- Atrial thrombosis due to stagnation of blood in the fibrillating atria. The formed thrombi may embolize in the systemic and pulmonary circulations. 2- Heart failure due to loss of the atrial contribution to contractility and the cardiac output. Atrial fibrillation (AF) progressed to ventricular fibrillation (VF) Treatment of Atrial Fibrillation Pharmacologic Management of Patients with Recurrent Persistent or Permanent AF: - Recurrent Persistent AF: A) Minimal or no symptoms: Anticoagulation and rate control as needed. B) Disabling symptoms in AF: 1- Anticoagulation and rate control 2- Antiarrhythmic drug therapy
  51. 51. 51 3- Electrical cardioversion as needed, continue anticoagulation as needed and therapy to maintain sinus rhythm - Permanent AF: Anticoagulation and rate control as needed. AF management Antiarrhythmic Drug Therapy to Maintain Sinus Rhythm in Patients with Recurrent Paroxysmal or Persistent AF: A) No or minimal heart disease: 1- Flecainide, propafenone, sotalol 2- Amiodarone, dronedarone, dofetilide, Disopyramide, procainamide, quinidine 3- Consider non-pharmacological options (ablation). B) Heart disease present: a- Heart failure: Amiodarone, dofetilide 1- Coronary artery disease: Sotalol, Amiodarone, dofetilide 2- Dronedarone is allowed only in HF class I or II with precaution. 3- Vernakalant I.V. for aute AF of less than 7 days duration, with many precautions and contraindications. C) Hypertension: With 1- With LVH (septum greater than or equal to 1.4 cm): Amiodarone 2- Without this degree of LVH: - Flecainide, propafenone.
  52. 52. 52 Drugs for Pharmacologic Cardioversion of AF (Rhythm control) Drug Route of Admin. And Dosage Amiodarone Oral: 1.2 to 1.8 g /day then 200 to 400 mg /d maintenance. IV: 1.2 g /d IV continuous or in divided doses, then 200 to 400 mg /d maintenance Dofetilide Oral: Creatinine clearance > 60 ml/min: 500 mcg BID Flecainide Oral 200 to 300 mg IV: 1.5 to 3 mg /kg over 10 to 20 min Propafenone Oral: 450 to 600 mg IV: 1.5 to 2 mg per kg over 10 to 20 min Orally Administered Pharmacological Agents for Heart Rate Control in Patients with AF Drug Maintenance dose Digoxin 0.125 to 0.375 mg daily Metoprolol* 25 to 100 BID Propranolol 80 to 360 mg daily in divided doses Verapamil 120 to 360 mg daily in divided doses Diltiazem 120 to 360 mg daily in divided doses Anticoagulation of Patients with Atrial Fibrillation: Indications Rheumatic mitral valve disease with recurrent or chronic atrial fibrillation. Dilated cardiomyopathy with recurrent persistent or chronic atrial fibrillation. Prosthetic valves. Prior to (>3 weeks) elective cardioversion of persistent or chronic atrial fibrillation, and also for 3 weeks after cardioversion (because of atrial stunning).
  53. 53. 53 Coronary heart disease or hypertensive heart disease with recurrent persistent or chronic atrial fibrillation Atrial fibrillation in thyrotoxicosis (while awaiting long-term control; elective cardioversion) Chronic or persistent lone atrial fibrillation, age >60 years Controversial; or limited data Coronary or hypertensive heart disease with normal left atrial size, after first episode of paroxysmal atrial fibrillation Elective cardioversion of atrial fibrillation of short duration (2-3 days) with normal left atrial size Chronic or persistent lone atrial fibrillation, age <60 years Not indicated Lone atrial fibrillation, short paroxysms (<48 h) Most clinical settings associated with short paroxysms (minutes to hours) Relative contraindications Difficulty controlling prothrombin times. Dementia Malignancies, especially associated with bleeding risk Prior major bleeding events. Uncontrolled hypertension Treatment of Cardiac Arrhythmias with Catheter Ablative Techniques Radiofrequency ablation destroys tissue by controlled heat production. Catheter ablation is used to treat patients with four major tachyarrhythmias: atrial flutter/fibrillation, AV nodal reentry, accessory pathways and ventricular tachycardia. VENTRICULAR TACHYCARDIA Specific Forms of Ventricular Tachycardia Duration: Salvo (3-5 impulses) Nonsustained VT: (6 impulses, up to 29 seconds) Sustained VT: (>30 seconds) The electrocardiographic diagnosis of ventricular tachycardia is suggested by the occurrence of a series of three or more bizarrely shaped premature ventricular complexes whose duration exceeds 120 msec, with the ST-T pointing opposite to the major QRS deflection.
  54. 54. 54 The rates range from 70 to 250 beats/min. Ventricular tachycardia can be sustained, defined arbitrarily as lasting longer than 30 sec or requiring termination because of hemodynamic collapse, or nonsustained (Unsustained), when it stops spontaneously in less than 30 sec. Ventricular tachycardia (Wide QRS tachycardia) Management: Intravenous lidocaine or amiodarone, followed by an infusion of the successful drug. If the arrhythmia does not respond to medical therapy, electrical DC cardioversion can be employed. Ventricular tachycardia in a patient with right ventricular dysplasia.
  55. 55. 55 CONGENITAL LONG QT INTERVAL SYNDROME The normal QT interval is .43 sec. The congenital long QT interval syndrome, which is present persistently from childhood, is characterized by the presence of long QT intervals on the standard 12-lead ECG. The affected patients are prone to episodes of torsade de pointes (ventricular tachycardia with special polymorphic configuration), which may cause transient light-headedness or syncope or sudden cardiac death. Arrhythmias may occur at rest, under emotional stress, or with exercise. ACQUIRED LONG QT INTERVAL SYNDROME Causes: Antiarrhythmic drugs as quinidine. There is a growing list of other drugs that may prolong the QT interval, and establish susceptibility to torsade de pointes. These include the phenothiazines, certain antibiotics, pentamidine, cocaine, and terfenadine, among others. Management of Congenital Long QT Interval Syndrome: Long-term therapy includes B-adrenergic blockade. Placement of an ICD should be considered for patients with resistant arrhythmias. CARDIOVERSION AND DEFIBRILLATION Differences between cardioversion and defibrillation: Cardioversion Defibrillation Elective Emergency Synchronized Non-synchronized For AF, A. flutter, SVT, VT For V. fibrillation 50, 100, 150, 200 Joules Start by 200 Joules Need sedative first Patient is unconscious VENTRICULAR FLUTTER AND FIBRILLATION MANAGEMENT: Immediate nonsynchronized DC electrical shock using 200 to 360 joules is mandatory treatment for ventricular fibrillation. Cardiopulmonary resuscitation is employed only until defibrillation equipment is ready. Time should not be wasted with cardiopulmonary resuscitation maneuvers if electrical defibrillation can be done promptly.
  56. 56. 56 The Implantable Cardioverter Defibrillator (ICD) Apparatus (pacemaker) that gives electric shock if the patient develops ventricular fibrillation. The pacemaker is inserted in the sub-pectoral area. ICD indications A. Cardiac arrest not due to acute ischemia or infarction or reversible causes. B. Documented sustained VT with hemodynamic compromise. C. Syncope of unknown origin in structural heart disease patients with inducible sustained VT. D. Cardiomyopathy ischemic or non-ischemic with ejection fraction 30% or lower (MADIT II results). AV HEART BLOCK Heart block is a disturbance of impulse conduction that can be permanent or transient, owing to anatomical or functional impairment. The conduction disturbance is classified by severity in three categories. During first degree heart block, conduction time is prolonged but all impulses are conducted (P-R interval > 0.2 sec.). Second degree heart block occurs in three forms: Mobitz type I (Wenckebach) and type II; and persistent 2:1 block. Mobitz Type I heart block is characterized by a progressive lengthening of the conduction time until an impulse is not conducted (Fig). Mobitz Type II heart block denotes occasional (Mobitz II) or repetitive sudden block of conduction of an impulse without prior measurable lengthening of conduction time. When no impulses are conducted, complete or third degree block is present. Mobitz type I (Wenckebach) block
  57. 57. 57 Mobitz Type II second degree heart block COMPLETE AV BLOCK ELECTROCARDIOGRAPHIC RECOGNITION: Complete AV block occurs when no atrial activity conducts to the ventricles and therefore the atria and ventricles are controlled by independent pacemakers. Thus, complete AV block is one type of complete AV dissociation. The ventricular focus is usually located just below the region of block, which can be above or below the His bundle bifurcation. The ventricular rate of acquired complete heart block is less than 40 beats/min but may be faster in congenital complete AV block. CLINICAL FEATURES. Block proximal to the His bundle generally exhibits normal QRS complexes and rates of 40-60 beats/min because the escape focus that controls the ventricle arises in or near the His bundle. Causes: Surgery, electrolyte disturbances, endocarditis, tumors, Chagas' disease, rheumatoid nodules, calcific aortic stenosis, myxedema, polymyositis, infiltrative processes (such as amyloid, sarcoid, or scleroderma). In the adult, drug toxicity, coronary disease, and degenerative processes appear to be the most common causes of AV heart block. COMPLETE AV BLOCK MANAGEMENT: Temporary or permanent pacemaker insertion is indicated in patients with symptomatic bradyarrhythmias. Vagolytic agents such as atropine (novatropine 15 drops every 8 hours) are useful, while catecholamines such as isoproterenol (Allupent syrup 5 ml every 8 hours) can be used transiently to treat patients who have heart block. The use of transcutaneous pacing is preferable.
  58. 58. 58 ELECTROPHYSIOLOGIC STUDY EP study is an invasive procedure in which intracardiac electrode catheters are used to evaluate cardiac arrhythmias and to select various therapeutic options. Indications of EPS: Diagnostic:  Aborted SCD (sudden cardiac death). - Syncope of undetermined cause.  Recurrent WCT (wide complex tachycardia). - Ventricular tachycardia.  Recurrent tachycardia with WPW syndrome.  Symptomatic refractory NCT (narrow complex tachycardia). Therapeutic:  Catheter ablation for AVNRT (AV nodal reentrant tachycardia), WPW (Wolff Parkinson White syndrome), VT (Ventricular Tachycardia), Atrial fibrillation.  Acute termination of hemodynamically unstable tachycardias. CARDIAC PACEMAKERS Cardiac pacemakers are devices either implanted permanently or inserted temporarily, consisting of a pulse generator and an electrode catheter that is placed transvenously into the right ventricle and/or atrium. Small electrical impulses, generated by the pulse generator and delivered via the electrode catheter depolarize the heart. Pacemakers are widely used for treating bradyarrhythmias but can also be useful for treatment of some tachyarrhythmias. Temporary pacing is indicated for symptomatic second or third degree heart block caused by transient drug intoxication or electrolyte imbalance in the setting of an acute MI, CHB, or Mobitz II second degree AV Block. Symptomatic sinus bradycardia, AF with a slow ventricular response. Indications for permanent pacemaker implantation: Symptomatic bradycardia, due to either sinus node dysfunction or AV nodal block, in absence of a reversible cause, constitutes a class I indications for permanent pacing. Asymptomatic conditions that are also considered class I indications for permanent pacing include: 1- 3rd degree AV Block .
  59. 59. 59 2- Persistent advanced 2nd degree or 3rd degree AVB after acute MI with demonstrated block in His-Purkinje system (BBB). 3- Chronic bifascicular or trifascicular block with intermittent type II second or third degree AV Block. Pacing modalities: a four-letter alphabetic code is used to identify pacing modalities. The first initial defines the chamber that is paced (V: ventricle, A: atrium, D: dual chamber). The second identifies the chamber that is sensed (V, A, D), the third indicates the response to sensed event (I: inhibited, T: triggered, D: dual function), and the fourth when present, denotes, R: rate responsive node. VVI & DDD modes are used most commonly. VVI units pace and sense ventricle and a sensed (native) event inhibits the ventricular stimulus. DDD units, pace and sense both chambers, events sensed in the atrium inhibit the atrial stimulus and trigger a ventricular response after an appropriate interval, where as ventricle-sensed events inhibit ventricular and atrial outputs. Antiarrhythmic Drugs Class Mode of Action Drugs Indication Dose Side Effects Class IA Reduces rate of entry of sodium into the cell Quinidine (Quinidine) For supraventricular and ventricular arrhythmias including conversion of AF or A flutter, SVT, VT 600 – 1000 mg/day Prolongation of QT interval, risk of Torsade de pointes. Quinidine syncope, quinidine induced sudden death. Diarrhea, vomiting Procainamide (Pronestyl) Is effective against supraventricular and ventricular arrhythmias 2-6 mg/min IV. 350- 1000 mg q 6 h PO SLE like syndrome, prolonged QT, nausea, rash, myalgia, Disopyramid e (Norpace) Is effective against supraventricular and ventricular arrhythmias 100-400 mg q 8 h Worsening of heart failure, anticholinergic actions as urine retention. Avoid in pts with
  60. 60. 60 glaucoma Class IB Lidocaine (Zylocain) Ventricular arrhythmias only 1-4 mg/min IV (50-150 mg IV loading dose) Confusion, convulsions Mexiletine (Mexitil) Ventricular arrhythmias only 150-300 mg q 6-8 h Confusion, tremor, bradycardia, hypotension Class IC Flecainide (Tambocor) Is very effective for ventricular and supraventricular tachycardias 100-200 mg q 12 h PO Aggravation of arrhythmia (proarrhythmia), negative inotropic effect, depression of sinus node Propafenone (Rytmonorm) Has a rule in treatment of many types of arrhythmias including supraventricular arrhythmias 150-300 mg q 8-12 h Negative inotropic effect Class II Beta adrenergi c blockers e.g. Propranolol (Inderal), Atenolol, Bisoprolol, Carvedilol For premature beats atrial and ventricular, for torsade de pointes, 10-200 mg q 8 h PO Bradycardia, hypotension, heart failure, intermittent claudication, worsening of asthma, impotence Class III Prolong action potential duration Amiodarone (Cordarone) Life-threatening ventricular arrhythmias, conversion and slowing of atrial fibrillation, AVNRT, tachycardias associated with WPWs 200-400 mg q 6-8 h Corneal deposits, photosensitivity, skin pigmentation, thyroid disturbances (hypo & hyperfunction), alveolitis, liver enzyme elevation Sotalol (Betacor) Effective in supraventricular 80-160 mg x 2-3 PO Torsade de pointes,
  61. 61. 61 and ventricular arrhythmias bronchospasm in asthmatic patients Class IV Calcium antagonis ts Verapamil (Isoptin) Diltiazem Slow the ventricular rate in AF or flutter, treat and prevent AVNRT 0.1 Mg/kg IV 40-160 mg q 6-8 h PO 60-120 mg q 6-8 h PO Constipation, edema of LL, negative inotropic effect Unclas sified Activates K+ channels Adenosine (Adenocore) Is very effective for the acute conversion of paroxysmal SVT 6-18 mg IV rapidly Contraindicated in sick sinus s., or 2nd or 3rd˚ heart block. Antidote is theophylline Enhances central and periphera l vagal tone Digoxin (Lanoxin) Slow ventricular rate in AF, flutter 0.5 – 1 mg IV or 0.125 – 0.25 mg /d PO Bradycardias and tachycardias (atrial, junctional, vent. tachycardia), nausea, vomiting Note: there are new two important antiarrhythmic drugs: Dronedarone (Multaq), and Vernakalant.