HEART   September 19, 2011
NORMAL   250 to 300 gms. in females   300 to 350 gms. in males   right ventricular thickness 0.3 to 0.5 cm.   left ven...
MYOCARDIUM   Composed of branching and anastomosing striated    muscle cells (cardiac myocytes)   Cardiac myocytes have ...
Myocardium   SARCOMERE – functional intracellular contractile    unit of the cardiac muscle.   Shorter sarcomere have co...
Myocardium    Atrial myocytes are generally smaller in     diameter and less structured than ventricular     myocytes.  ...
Myocardium   Specialized excitatory and conduction myocytes    regulate the heart’s rate/rhythm     SA Node - Sinoatrial...
Blood Supply   Heart generates energy exclusively by the    oxidation of substrates so it relies heavily on    adequate f...
Blood supply   Three major epicardial arteries:     Left anterior descending (LAD)     Left circumflex (LCX)     Right...
Blood Supply   Blood flows during diastole when the    microcirculation is not compressed by the    contraction.   Anter...
Blood supply   Functionally the right and left coronary arteries    behave as end arteries   Collateral circulation – us...
Valves   Maintain unidirectional blood flow   Normally are thin and translucent   Free margins of AV valves are attache...
Effects of Aging     Brown atrophy - lipofuscin deposits     Basophilic degeneration - gray blue deposits      (?glucan)...
Cardiovascular Dysfunction   Loss of blood   Disorders of cardiac conduction   Obstructed flow   Regurgitant flow   P...
Congestive Heart Failure   Heart unable to maintain an output sufficient for    the metabolic requirements of the body. ...
Congestive heart failure   Factors that affect cardiac response to hemodynamic    burden:     Frank-Starling  Mechanism ...
Congestive heart failure   Most instances are the result of progressive    deterioration of myocardial contractile functi...
Cardiac Hypertrophy      Normal myocytes = 15 µm in diameter.      Hyperplasia cannot occur in an adult heart.      Pat...
Cardiac Hypertrophy   In many cases heart failure is preceded by cardiac    hypertrophy   There is an increase in the ra...
Cardiac Hypertrophy   The pattern of hypertrophy reflects the nature of    the stimulus:     Pressureoverloaded ventricl...
Cardiac hypertrophy constitute atenuous balance between adaptivecharacteristics and potentiallydeleterious structural and
Physiologic hypertrophy inducedby regular strenuous exercise seems tobe an extension of normal growth andhave minimal or n...
Congestive heart failure ischaracterized by diminished cardiacoutput (forward failure) or dammingback of blood in the veno...
Congestive heart failure    Morphologic changes of CHF are distant from the heart and are produced by the hypoxic and cong...
Congestive heart failure   Left-sided and right-sided failurecan occur independently but failure ofone side cannot exist f...
Left Sided Heart Failure   Most often caused by:    1.   Ischemic heart disease    2.   Hypertension    3.   Aortic and m...
Left Sided Heart Failure   Left ventricle is usually hypertrophied & often    dilated.   Secondary enlargement of the at...
Lungs - Left sided heart failure.   Pulmonary congestion and edema   Lung changes include:    1. Perivascular and inters...
Kidney - Left sided heart failure.   Reduction in renal perfusion which activate renin-    angiotensin-aldosterone system...
Brain - Left sided heart failure.    Hypoxic encephalopathy withirritability, loss of attention span andrestlessness which...
Right sided Heart failure.   Usually a consequence of left sided    heart failure.   Pure right sided heart failure occu...
Right sided Heart failure. LUNGS – minimal congestion LIVER     slightly            increased in size and weight     “...
Right sided Heart failure. KIDNEY – congestion BRAIN- hypoxic encephalopathy Subcutaneous edema on dependent  portions ...
In many cases of frank cardiacdecompensation, the patientpresents with biventricularcongestive heart failure.
TYPES OF HEART DISEASE   ISCHEMIC HEART DISEASE   HYPERTENSIVE HEART DISEASE   VALVULAR HEART DISEASE   NON-ISCHEMIC M...
18. heart part 1   basic & congestive heart failure
18. heart part 1   basic & congestive heart failure
18. heart part 1   basic & congestive heart failure
18. heart part 1   basic & congestive heart failure
18. heart part 1   basic & congestive heart failure
18. heart part 1   basic & congestive heart failure
18. heart part 1   basic & congestive heart failure
18. heart part 1   basic & congestive heart failure
18. heart part 1   basic & congestive heart failure
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18. heart part 1 basic & congestive heart failure

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18. heart part 1 basic & congestive heart failure

  1. 1. HEART September 19, 2011
  2. 2. NORMAL 250 to 300 gms. in females 300 to 350 gms. in males right ventricular thickness 0.3 to 0.5 cm. left ventricular thickness 1.3 to 1.5 cm. Hypertrophy vs. dilatation. cardiomegaly
  3. 3. MYOCARDIUM Composed of branching and anastomosing striated muscle cells (cardiac myocytes) Cardiac myocytes have 5 major components:  Cell membrane  Sarcoplasmic reticulum  Contractile elements  Mitochondrion  nucleus
  4. 4. Myocardium SARCOMERE – functional intracellular contractile unit of the cardiac muscle. Shorter sarcomere have considerable overlap of actin and myosin with consequent reduction in contractile forces (Frank-Starling mechanism) Cardiac myocytes account for 90% of the volume of the heart but only 25% of the total cells (other cells – endothelial cells and connective tissue cells)
  5. 5. Myocardium  Atrial myocytes are generally smaller in diameter and less structured than ventricular myocytes.  Some atrial cells have distinctive electron dense granules – specific atrial granules.  Storage site of atrial natriuretic peptides, that can induce vasodilatation, natriuresis, suppression of renin-angiotensin-aldosterone axis and fall in arterial pressure.
  6. 6. Myocardium Specialized excitatory and conduction myocytes regulate the heart’s rate/rhythm  SA Node - Sinoatrial pacemaker  AV Node  Bundle of His  Right and left bundle branches
  7. 7. Blood Supply Heart generates energy exclusively by the oxidation of substrates so it relies heavily on adequate flow of oxygenated blood. Epicardial coronary arteries are 5-10 cm. long, 2-4 mm in diameter that run along the external surface of the heart Intramural arteries – penetrate the myocardium
  8. 8. Blood supply Three major epicardial arteries:  Left anterior descending (LAD)  Left circumflex (LCX)  Right coronary artery (RCA)
  9. 9. Blood Supply Blood flows during diastole when the microcirculation is not compressed by the contraction. Anterior descending branch of the left coronary artery - apex, anterior surface of the left ventricle and anterior 2/3 of the interventricular septum Right coronary artery - right ventricular free wall, adjacent half of the posterior wall of the left ventricle & posterior third of interventricular septum.
  10. 10. Blood supply Functionally the right and left coronary arteries behave as end arteries Collateral circulation – usually with little blood coursing through them
  11. 11. Valves Maintain unidirectional blood flow Normally are thin and translucent Free margins of AV valves are attached to chordae tendinae which are attached to papillary muscles Lined by endothelium and composed of a dense collagenous core (fibrosa) and loose connective tissue (spongiosa)
  12. 12. Effects of Aging  Brown atrophy - lipofuscin deposits  Basophilic degeneration - gray blue deposits (?glucan)  fewer myocytes, increased collagen and variable deposits of amyloid.  Reduced left ventricular cavity  calcification of mitral annulus
  13. 13. Cardiovascular Dysfunction Loss of blood Disorders of cardiac conduction Obstructed flow Regurgitant flow Pump failure  Contractile dysfunction (systolic failure)  Inadequate filling.
  14. 14. Congestive Heart Failure Heart unable to maintain an output sufficient for the metabolic requirements of the body. Occurs either because of a decreased myocardial capacity to contract or because or an inability to fill the cardiac chambers with blood. Most due to systolic dysfunction.
  15. 15. Congestive heart failure Factors that affect cardiac response to hemodynamic burden:  Frank-Starling Mechanism  Myocardial hypertrophy with or without cardiac chamber dilation  Activation of neurohumoral systems  Release of norepinephrine by adrenergic cardiac nerves  Activation of renin-angiotensin-aldosterone system  Release of atrial natriuretic peptide
  16. 16. Congestive heart failure Most instances are the result of progressive deterioration of myocardial contractile function (systolic dysfunction). The most frequent causes are hypertension and IHD Diastolic dysfunction – when heart cannot fill properly (e.g. massive left ventricular hypertrophy, fibrosis etc.)
  17. 17. Cardiac Hypertrophy  Normal myocytes = 15 µm in diameter.  Hyperplasia cannot occur in an adult heart.  Pattern of hypertrophy reflects the stimulus:  concentric hypertrophy in pressure over-loaded ventricles ex. HPN or aortic stenosis.  Eccentric hypertrophy in volume over-loaded ventricles ex. mitral regurgitation.
  18. 18. Cardiac Hypertrophy In many cases heart failure is preceded by cardiac hypertrophy There is an increase in the rate of protein synthesis, the amount of protein in each cell, the size of the myocyte, the number of sarcomeres and mitochondria – consequently the total mass and size of the heart.
  19. 19. Cardiac Hypertrophy The pattern of hypertrophy reflects the nature of the stimulus:  Pressureoverloaded ventricles develop concentric hypertrophy (reduced cavity diameter)  Volume overloaded ventricles develop hypertrophy accompanied by dilation (increased ventricular diameter).
  20. 20. Cardiac hypertrophy constitute atenuous balance between adaptivecharacteristics and potentiallydeleterious structural and
  21. 21. Physiologic hypertrophy inducedby regular strenuous exercise seems tobe an extension of normal growth andhave minimal or no deleterious effect.
  22. 22. Congestive heart failure ischaracterized by diminished cardiacoutput (forward failure) or dammingback of blood in the venous system(backward failure)
  23. 23. Congestive heart failure Morphologic changes of CHF are distant from the heart and are produced by the hypoxic and congestive effects of the failing circulation.
  24. 24. Congestive heart failure Left-sided and right-sided failurecan occur independently but failure ofone side cannot exist for long withouteventually straining the other –producing global heart failure.
  25. 25. Left Sided Heart Failure Most often caused by: 1. Ischemic heart disease 2. Hypertension 3. Aortic and mitral valvular diseases 4. Non-ischemic Myocardial diseases.
  26. 26. Left Sided Heart Failure Left ventricle is usually hypertrophied & often dilated. Secondary enlargement of the atrium is frequently present.
  27. 27. Lungs - Left sided heart failure. Pulmonary congestion and edema Lung changes include: 1. Perivascular and interstitial transudate 2. Progressive edematous widening of alveolar septa. 3. Accumulation of edema fluid in alveolar spaces. “heart-failure cells”
  28. 28. Kidney - Left sided heart failure. Reduction in renal perfusion which activate renin- angiotensin-aldosterone system inducing retention of salt and water with consequent expansion of the interstitial fluid and blood volume. Acute tubular necrosis. Pre-renal azotemia.
  29. 29. Brain - Left sided heart failure. Hypoxic encephalopathy withirritability, loss of attention span andrestlessness which may evenprogress to stupor and coma.
  30. 30. Right sided Heart failure.  Usually a consequence of left sided heart failure.  Pure right sided heart failure occurs in Cor pulmonale i.e.. Right ventricular pressure overload induced by intrinsic diseases of the lung or pulmonary vasculature.
  31. 31. Right sided Heart failure. LUNGS – minimal congestion LIVER  slightly increased in size and weight  “nutmeg” appearance
  32. 32. Right sided Heart failure. KIDNEY – congestion BRAIN- hypoxic encephalopathy Subcutaneous edema on dependent portions of the body
  33. 33. In many cases of frank cardiacdecompensation, the patientpresents with biventricularcongestive heart failure.
  34. 34. TYPES OF HEART DISEASE ISCHEMIC HEART DISEASE HYPERTENSIVE HEART DISEASE VALVULAR HEART DISEASE NON-ISCHEMIC MYOCARDIAL DISEASE CONGENITAL HEART DISEASE

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