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Cardiovascular System<br />C. Washington RN, MSNEd<br />
Physical Assessment<br />Vital signs wnl<br />No abnormal heart sounds<br />Strong & equal peripheral pulses<br />Even & u...
Key Points<br />Discomfort<br />Indigestion<br />Squeezing<br />Heaviness<br />Viselike<br />Transient loss of consciousne...
Key Points<br />Assess the filling volume & pressure on the right side of heart<br />Swishing sounds that develop in narro...
Diagnostic Assessment<br />No serum markers of myocardial damage<br />Serum lipids within normal ranges<br />Normal C-reac...
Key Points:  Safety<br />Assess for allergy to iodine<br />After invasive test monitor insertion site for bleeding and hem...
Key Points:  Health Promotion<br />Identify pts at risk for<br />cardiovascular disease<br />Psychological Stress<br />Fam...
Key Points:  Teaching<br />How to reduce risks of<br />Disease<br />Exercise<br />Diet modification<br />Smoking cessation...
Coronary Heart Disease<br />Atherosclerotic plaque in coronary arteries<br />May be asmptomatic<br />May lead to Angina, h...
CAD<br />Most common cause of ↓ coronary blood flow is plaque formation <br />Lipoproteins & fibrous tissue in arterial wa...
CHD:  Diagnostic Tests<br />Diagnosis based on history & risk factors<br />↑ triglyceride/LDL & ↓ HDL levels<br />Total se...
Risk Factor Management<br />Stop smoking improves HDL levels<br />↓ saturated fat & cholesterol intake<br />↑ soluble and ...
Risk Factor Management<br />Mevacor, Zocar, Lipitor- Monitor liver function & muscle pain/tenderness (may cause myopathy)<...
CAD  Nursing Diagnosis <br />Imbalanced Nutrition:  More than body requirements<br />Ineffective Health Maintanance<br />
CAD:  Assessment<br />Focus on identifying risk factors<br />Health history:  <br />CP, SOB, <br />weakness, current diet<...
CAD:  Physical Assessment<br />Weight<br />Height<br />BMI<br />Blood Pressure<br />Strenght and equality of peripheral pu...
Atherosclerosis<br />Injury-> lipoproteins collect in lining of artery <br />Macrophages go to site as part of inflammator...
Myocardial IschemiaPathophysiology<br />Oxygen supply inadequate to meet metabolic demands of cardiac cells<br />Coronary ...
Cardiac ischemia<br />Occurs when blood flow to the heart muscle (myocardium) is obstructed by a partial or complete block...
Angina<br />
Angina:  Common Causes<br />Atherosclerotic heart disease<br />Hypertension<br />Coronary artery spasm<br />Hypertrophic c...
Angina:  Pain Assessment<br />Heavy, squeezing, pressing, burning, choking, aching & apprehension<br />Substernal, radiati...
Angina:  Diagnostic Information<br />ECG:  ST depression & T wave inversion<br />Exercise stress test:  ST depression and ...
Angina:  Nursing Assessment<br />Dyspnea<br />Nausea, vomiting<br />Fatigue<br />Diaphoresis, pallor, weakness<br />Syncop...
CHD: Nonmodifiable Risk Factors<br />Age (50% 65 or older)<br />Gender (Men affected at early age)<br />Race (AA ↑ inciden...
CHD: Modifiable Risk Factors<br />Hypertension<br />Diabetes<br />
CHD: Modifiable Risk Factors<br />Hyperlipidemia <br />   LDLs = less desirable lipoproteins<br />   HDLs = highly desirab...
CAD:  Modifiable Risk Factors<br />Undesirable<br />Desirable<br />
CHD: Modifiable Risk Factors<br />
Modifiable Risk Factors<br />
CHD:  Modifiable Risk Factors<br />Physical Activity<br />
CHD:  Modifiable Risk Factors<br />
Modifiable Risk Factors<br />
Angina:  Nursing Diagnosis<br />Pain related to ……<br />Anxiety related to ….<br />
Angina:  Nursing Plans & Interventions<br />Monitor meds & instruct on proper administration<br />Assess factors causing p...
Angina:  During an attack<br />Provide immediate rest<br />Take vital signs<br />Record an ECG<br />3 NTG tablets, 5 minut...
Angina:  Physical Activity<br />Avoid isometric activity<br />Exercise program<br />Resume sexual activity after exercise ...
Angina:  Diet<br />Modify saturated fats and sodium<br />Antilipemic meds to lower cholesterol levels<br />
Angina:  Medical InterventionsPercutaneoustransluminal coronary angioplasty (PTCA)<br />
Angina:  Medical InterventionsCoronary Artery Stent<br />
Angina:  Medical InterventionsArthrectomy<br />Arthrectomy:  a cath with a collection chamber is used to remove plaque tha...
Inadequate Oxygenation & Tissue Perfusion:  Assessment<br />Report pain:<br />Chest<br />Shoulder<br />Arm <br />Jaw<br />...
Peripheral Vascular Disease<br />Can be due to arterial or venous pathology<br />
PVD:  Predisposing factors<br />Arterioclerosis<br />Advanced age<br />H/O DVT<br />Valvular incompetence<br />Arterial<br...
PVD:  Associated Diseases<br />Raynaud disease<br />Buerger disease<br />Diabetes<br />Acute occlusion<br />Varicose veins...
PVD:  Skin Assessment<br />Smooth <br />Shiny<br />Loss of hair<br />Thickened nails<br />Brown pigment around ankles<br /...
PVD:  Color<br />Pallor on elevation<br />Rubor when dependent<br />Cyanotic when dependent<br />Arterial<br />Venous<br />
PVD:  Temperature/Pulses<br />Cool<br />Pulse decreased or absent<br />Warm<br />Pulse normal<br />Arterial<br />Venous<br />
PVD:  Pain Assessment<br />Arterial<br />Sharp<br />Increases with walking and elevation<br />Intermittent claudication<br...
PVD:  Ulcers<br />Very painful<br />Occur on lateral lower legs, toes, heels<br />Demarcated edges<br />Necrotic<br />Not ...
PVD:  Nursing Diagnosis<br />Ineffective tissue perfusion<br />Activity intolerance<br />Impaired skin integrity<br />Risk...
PVD:  Noninvasive Treatment<br />Stop smoking<br />Topical antibiotic<br />Saline dressing<br />Bedrest, immobilization<br...
PVD:  Surgery<br />Embolectomy<br />Endarterectomy<br />Arterial bypass<br />Percutaneoustransluminal angioplasty<br />Amp...
PVD:  Nursing Plans & Interventions<br />Monitor extremities color, temp sensation, pulse quality<br />Schedule activities...
PVD:  Teach<br />Change position frequently<br />Wear nonrestricitve clothing<br />Avoid crossing legs<br />Keep legs in d...
PVD:  PreOp & PostOp Care<br />Maintain affected extremity in a level position (if venous)<br />Slightly dependent positio...
Key Points:  Vascular Problems<br />Take vital signs<br />Assess peripheral pulses<br />Assess capillary refill<br />Check...
Electrocardiogram (ECG)<br />Reflection of the heart&apos;s electrical circuit and its activity. <br />
Coronary Circulation <br />The heart derives its arterial supply from the coronary sinuses which lie either side of the ro...
Right Coronary Artery<br /><ul><li>Supplies the right side of the heart via the Right Main),
Supplies the inferior border (via Right Marginal branch)
Supplies the posterior surface (via Right Posterior Descending branch).
It also supplies the Sinoatrial node and Atrioventricular node in 90% and 65% of people respectively.
Impairment of the right coronary circulation causes inferior and posterior infarction as well as bradycardia and varying d...
The other branch of the left Main Stem, the Left Circumflex, winds around the posterior surface of the left ventricle, ana...
Impairment of the left coronary circulation causes anterior and lateral infarction
Where the left circumflex comes across to supply the territory of the right coronary artery  it may also lead to inferior ...
In Summary<br />The polarized or resting cell will carry a negative charge on the inside. When depolarized, the opposite w...
Repolarization<br />The return of electrical charges to their original state. <br />This process must happen before the ce...
Electric Circuit of the Heart:  SA Node<br />The intrinsic electrical circuit of the heart <br />‘natural pacemaker&apos;<...
Electric Circuit of the Heart:  AV Node<br />Regarded as the ‘gatekeeper&apos; or resistor in the circuit <br />Tries to m...
Electric Circuit of the Heart <br />
Electrical conduction<br />The electrical conduction through circuits causes a rapid wave of depolarization to spread acro...
Electrical conduction<br />The electrical baseline of the ECG from is known as the iso-electric line.<br />Deflections abo...
EKG Paper<br />Grid where time is measured along the horizontal axis. <br />Each small square is 1 mm in length and repres...
Calculating Heart Rate<br />When the rhythm is regular, the heart rate is 300 divided by the number of large squares betwe...
Calculating Heart Rate<br />The second method can be used with an irregular rhythm to estimate the rate. <br />Count the n...
P Wave<br />First small positive deflection before the QRS complex <br />Atrial depolarization <br />width &lt;0.12 sec<br />
PR Interval <br />Distance from start of P wave to start of QRS complex <br />Conduction time from SAN through the AV node...
Q Wave <br />First negative deflection after the P wave and before the R wave <br />Represents conduction from the opposit...
R Wave <br />First positive deflection after the P wave <br />Ventricular depolarization <br />
S Wave <br />First negative deflection after the R wave<br />Ventricular depolarization <br />
QRS Complex <br />Complex including the Q, R and S waves<br />Complete ventricular depolarization <br />&lt;0.12 seconds <...
ST Segment <br />Segment between the end of the S wave and the start of the T wave<br />First part of ventricular repolari...
T Wave <br />Positive wave after the QRS complex <br />Ventricular repolarization <br />
QT Interval<br />Start of the QRS complex to the end of the T wave<br />Ventricular depolarization and repolarization<br /...
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Cardiovascular System

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Transcript of "Cardiovascular System"

  1. 1. Cardiovascular System<br />C. Washington RN, MSNEd<br />
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  8. 8. Physical Assessment<br />Vital signs wnl<br />No abnormal heart sounds<br />Strong & equal peripheral pulses<br />Even & unlabored breathing<br />Regular heart beat<br />No pallor, cyanosis, or clubbing No syncope, fatigue, or chest pain<br />No edema<br />Can perform ADLs without dyspnea<br />
  9. 9. Key Points<br />Discomfort<br />Indigestion<br />Squeezing<br />Heaviness<br />Viselike<br />Transient loss of consciousness<br />Common in older adults<br />Cardiac Pain<br />Syncope<br />
  10. 10. Key Points<br />Assess the filling volume & pressure on the right side of heart<br />Swishing sounds that develop in narrowed arteries<br />Jugular Vein Pressure<br />Bruits<br />
  11. 11. Diagnostic Assessment<br />No serum markers of myocardial damage<br />Serum lipids within normal ranges<br />Normal C-reactive protein<br />Normal ECG<br />
  12. 12. Key Points: Safety<br />Assess for allergy to iodine<br />After invasive test monitor insertion site for bleeding and hematoma formation<br />Assess vital signs carefully<br />Report new dysrhythmias after testing<br />
  13. 13. Key Points: Health Promotion<br />Identify pts at risk for<br />cardiovascular disease<br />Psychological Stress<br />Family history<br />Diabetes<br />Hyperlipidemia<br />HTN<br />Overweight<br />Physical inactivity<br />Smoking<br />
  14. 14. Key Points: Teaching<br />How to reduce risks of<br />Disease<br />Exercise<br />Diet modification<br />Smoking cessation<br />Medications<br />Inform pt about<br />nonmodifiable risk<br />factors<br />Family history<br />Gender<br />genetics<br />
  15. 15. Coronary Heart Disease<br />Atherosclerotic plaque in coronary arteries<br />May be asmptomatic<br />May lead to Angina, heart attack, dysrhythmias, heart failure, or death<br />Cause of atherosclerotic plaque is unknown<br />May be linked to certain risk factors<br />
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  21. 21. CAD<br />Most common cause of ↓ coronary blood flow is plaque formation <br />Lipoproteins & fibrous tissue in arterial wall<br />Theory: begins with an injury to or inflammation of endothelial cells lining the artery<br />Endothelial damage promotes platelet adhesion & aggregation & attracts leukocytes to area<br />
  22. 22. CHD: Diagnostic Tests<br />Diagnosis based on history & risk factors<br />↑ triglyceride/LDL & ↓ HDL levels<br />Total serum cholesterol<br />Lipid profile (triglyceride, HDL, LDL levels, & ratio of HDL to total cholesterol (ratio 1:5; ideal 1:3)<br />NPO 10-12 hrs<br />Etoh & many meds affect results<br />
  23. 23. Risk Factor Management<br />Stop smoking improves HDL levels<br />↓ saturated fat & cholesterol intake<br />↑ soluble and insoluable fibers<br />Exercise<br />Control HTN (maintaining 140/90 mmHg)<br />Blood sugar control<br />
  24. 24. Risk Factor Management<br />Mevacor, Zocar, Lipitor- Monitor liver function & muscle pain/tenderness (may cause myopathy)<br />If taking Digoxin, monitor for digoxin toxicity<br />If at risk for MI, low dose ASA<br />
  25. 25. CAD Nursing Diagnosis <br />Imbalanced Nutrition: More than body requirements<br />Ineffective Health Maintanance<br />
  26. 26. CAD: Assessment<br />Focus on identifying risk factors<br />Health history: <br />CP, SOB, <br />weakness, current diet<br />exercise patterns, <br />Meds<br />smoking hx<br />etoh intake<br />h/o heart disease, HTN, or diabetes<br />family h/o CHD<br />
  27. 27. CAD: Physical Assessment<br />Weight<br />Height<br />BMI<br />Blood Pressure<br />Strenght and equality of peripheral pulses<br />
  28. 28. Atherosclerosis<br />Injury-> lipoproteins collect in lining of artery <br />Macrophages go to site as part of inflammatory process<br />Platelets, cholesterol, & blood stimulates smooth muscle cells & connective tissue proliferate abnormally<br />Yellow fatty streak on inner lining of artery ->fibrous plaque develops ->collagen fibers proliferate -> blood lipids accumulate ->occludes vessel lumen<br />
  29. 29.
  30. 30. Myocardial IschemiaPathophysiology<br />Oxygen supply inadequate to meet metabolic demands of cardiac cells<br />Coronary perfusion & myocardial workload critical to meeting metabolic demands<br />Oxygen content in blood is a factor<br />
  31. 31. Cardiac ischemia<br />Occurs when blood flow to the heart muscle (myocardium) is obstructed by a partial or complete blockage of a coronary artery.<br />
  32. 32.
  33. 33. Angina<br />
  34. 34. Angina: Common Causes<br />Atherosclerotic heart disease<br />Hypertension<br />Coronary artery spasm<br />Hypertrophic cardiomyopathy<br />
  35. 35. Angina: Pain Assessment<br />Heavy, squeezing, pressing, burning, choking, aching & apprehension<br />Substernal, radiating to left arm and/or shoulder, jaw, right shoulder<br />Percipitated by exercise, exposure to cold, a heavy meal, mental tension, sexual intercourse<br />Relieved by rest and/or nitroglycerine<br />
  36. 36. Angina: Diagnostic Information<br />ECG: ST depression & T wave inversion<br />Exercise stress test: ST depression and hypotension<br />Stress echocardiogram: changes in wall motion<br />Coronary angiogram: coronary spasms<br />Cardiac catheterization: detects arterial blockage<br />
  37. 37. Angina: Nursing Assessment<br />Dyspnea<br />Nausea, vomiting<br />Fatigue<br />Diaphoresis, pallor, weakness<br />Syncope<br />Dysthythmias<br />
  38. 38. CHD: Nonmodifiable Risk Factors<br />Age (50% 65 or older)<br />Gender (Men affected at early age)<br />Race (AA ↑ incidence of HTN)<br />Genetic factors<br />
  39. 39. CHD: Modifiable Risk Factors<br />Hypertension<br />Diabetes<br />
  40. 40. CHD: Modifiable Risk Factors<br />Hyperlipidemia <br /> LDLs = less desirable lipoproteins<br /> HDLs = highly desirable lipoproteins<br />
  41. 41. CAD: Modifiable Risk Factors<br />Undesirable<br />Desirable<br />
  42. 42. CHD: Modifiable Risk Factors<br />
  43. 43. Modifiable Risk Factors<br />
  44. 44. CHD: Modifiable Risk Factors<br />Physical Activity<br />
  45. 45. CHD: Modifiable Risk Factors<br />
  46. 46. Modifiable Risk Factors<br />
  47. 47. Angina: Nursing Diagnosis<br />Pain related to ……<br />Anxiety related to ….<br />
  48. 48. Angina: Nursing Plans & Interventions<br />Monitor meds & instruct on proper administration<br />Assess factors causing pain (decrease these factors)<br />Teach risk factors/identify risk factors<br />
  49. 49. Angina: During an attack<br />Provide immediate rest<br />Take vital signs<br />Record an ECG<br />3 NTG tablets, 5 minutes apart<br />Emergency if no relief after NTG x 3<br />
  50. 50. Angina: Physical Activity<br />Avoid isometric activity<br />Exercise program<br />Resume sexual activity after exercise tolerated<br />Climb 2 flights of stairs without exertion<br />Take NTG before intercourse <br />
  51. 51. Angina: Diet<br />Modify saturated fats and sodium<br />Antilipemic meds to lower cholesterol levels<br />
  52. 52. Angina: Medical InterventionsPercutaneoustransluminal coronary angioplasty (PTCA)<br />
  53. 53. Angina: Medical InterventionsCoronary Artery Stent<br />
  54. 54. Angina: Medical InterventionsArthrectomy<br />Arthrectomy: a cath with a collection chamber is used to remove plaque that is trapped in the chamber<br />Coronary laser therapy<br />
  55. 55.
  56. 56.
  57. 57. Inadequate Oxygenation & Tissue Perfusion: Assessment<br />Report pain:<br />Chest<br />Shoulder<br />Arm <br />Jaw<br />Back<br />abdomen<br />Indigestion<br />Diaphoresis<br />Nausea<br />Vomiting<br />Anxious behavior<br />Palpitations<br />Fatigue<br />Disorientation/confusion<br />
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  59. 59.
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  61. 61.
  62. 62. Peripheral Vascular Disease<br />Can be due to arterial or venous pathology<br />
  63. 63. PVD: Predisposing factors<br />Arterioclerosis<br />Advanced age<br />H/O DVT<br />Valvular incompetence<br />Arterial<br />Venous<br />
  64. 64. PVD: Associated Diseases<br />Raynaud disease<br />Buerger disease<br />Diabetes<br />Acute occlusion<br />Varicose veins<br />Thrombophlebitis<br />Venous stasis ulcers<br />Arterial<br />Venous<br />
  65. 65. PVD: Skin Assessment<br />Smooth <br />Shiny<br />Loss of hair<br />Thickened nails<br />Brown pigment around ankles<br />Arterial<br />Venous<br />
  66. 66. PVD: Color<br />Pallor on elevation<br />Rubor when dependent<br />Cyanotic when dependent<br />Arterial<br />Venous<br />
  67. 67. PVD: Temperature/Pulses<br />Cool<br />Pulse decreased or absent<br />Warm<br />Pulse normal<br />Arterial<br />Venous<br />
  68. 68. PVD: Pain Assessment<br />Arterial<br />Sharp<br />Increases with walking and elevation<br />Intermittent claudication<br />Rest pain when hortizonal; relieved by dependent position<br />Persistant aching, full feeling, dull sensation<br />Relieved when horizonal (elevate and use TEDs)<br />Venous<br />
  69. 69. PVD: Ulcers<br />Very painful<br />Occur on lateral lower legs, toes, heels<br />Demarcated edges<br />Necrotic<br />Not edematous<br />Slightly painful<br />Occur on medial legs, ankles<br />Uneven edges<br />Superficial<br />Marked edema<br />Arterial<br />Venous<br />
  70. 70. PVD: Nursing Diagnosis<br />Ineffective tissue perfusion<br />Activity intolerance<br />Impaired skin integrity<br />Risk for infection<br />Pain<br />
  71. 71. PVD: Noninvasive Treatment<br />Stop smoking<br />Topical antibiotic<br />Saline dressing<br />Bedrest, immobilization<br />Fibrinolytic agents if clots a problem<br />Systemic antibiotics<br />Compression dressing<br />Limb elevation<br />Fibrinolytic agents and anticoagulants<br />Arterial<br />Venous<br />
  72. 72. PVD: Surgery<br />Embolectomy<br />Endarterectomy<br />Arterial bypass<br />Percutaneoustransluminal angioplasty<br />Amputation<br />Vein ligation<br />Thrombectomy<br />Debribement<br />Arterial<br />Venous<br />
  73. 73. PVD: Nursing Plans & Interventions<br />Monitor extremities color, temp sensation, pulse quality<br />Schedule activities<br />Rest<br />Keep extremities elevated (if venous)<br />Avoid crossing legs<br />Wear nonrestrictive clothing<br />Keep extremities warm<br />Do not use electric heating pads<br />
  74. 74. PVD: Teach<br />Change position frequently<br />Wear nonrestricitve clothing<br />Avoid crossing legs<br />Keep legs in dependent position<br />Wear shoes when ambulating<br />Obtain proper foot and nail care<br />Discourage smoking (vasoconstriction & spasms of arteries)<br />
  75. 75. PVD: PreOp & PostOp Care<br />Maintain affected extremity in a level position (if venous)<br />Slightly dependent position (if arterial)<br />Assess surgical site for hemorrhage<br />Anticoagulants continued to prevent thrombosis<br />Preoperative<br />Postoperative<br />
  76. 76. Key Points: Vascular Problems<br />Take vital signs<br />Assess peripheral pulses<br />Assess capillary refill<br />Check sensation and temperature<br />Pain assessment<br />Assess ulcer<br />Elevate legs if swollen unless arterial flow is poor<br />
  77. 77. Electrocardiogram (ECG)<br />Reflection of the heart&apos;s electrical circuit and its activity. <br />
  78. 78. Coronary Circulation <br />The heart derives its arterial supply from the coronary sinuses which lie either side of the root of the aorta. <br />The left and right sinus give rise to the left and right coronary artery and their branches, <br />
  79. 79. Right Coronary Artery<br /><ul><li>Supplies the right side of the heart via the Right Main),
  80. 80. Supplies the inferior border (via Right Marginal branch)
  81. 81. Supplies the posterior surface (via Right Posterior Descending branch).
  82. 82. It also supplies the Sinoatrial node and Atrioventricular node in 90% and 65% of people respectively.
  83. 83. Impairment of the right coronary circulation causes inferior and posterior infarction as well as bradycardia and varying degrees of heart block. </li></li></ul><li>Left Coronary Artery<br />Divides into the Left Anterior Descending Branch<br /><ul><li>Supplies the anterior surface of the left ventricle & the anterior 2/3 of the interventricular septum.
  84. 84. The other branch of the left Main Stem, the Left Circumflex, winds around the posterior surface of the left ventricle, anastamoses with the Right Posterior Descending artery.
  85. 85. Impairment of the left coronary circulation causes anterior and lateral infarction
  86. 86. Where the left circumflex comes across to supply the territory of the right coronary artery it may also lead to inferior infarction. </li></li></ul><li>Depolarization <br />In a cardiac cell, two primary chemicals provide the electrical charges: sodium (Na+) and potassium (K+).<br />In the resting cell, the potassium is mostly on the inside, while the sodium is mostly on the outside. <br />This results in a negatively charged cell at rest (the interior of the cardiac cell is mostly negative or polarized at rest). <br />When depolarized, the interior cell becomes positively charged and the cardiac cell will contract.<br />
  87. 87. In Summary<br />The polarized or resting cell will carry a negative charge on the inside. When depolarized, the opposite will occur.<br />This is due to the movement of sodium and potassium across the cell membrane.<br />Depolarization moves a wave through the myocardium.<br />As the wave of depolarization stimulates the heart’s cells, they become positive and begin to contract. <br />This cell-to-cell conduction of depolarization through the myocardium is carried by the fast moving sodium ions.<br />
  88. 88.
  89. 89. Repolarization<br />The return of electrical charges to their original state. <br />This process must happen before the cells can be ready conduct again. <br />Look at the next slide diagram and note the depolarization and repolarization phases as they are represented on the ECG.<br />
  90. 90.
  91. 91. Electric Circuit of the Heart: SA Node<br />The intrinsic electrical circuit of the heart <br />‘natural pacemaker&apos;<br />Receives both a parasympathetic and sympathetic nerve supply. <br />Lies at the junction of the Superior Vena Cava with the Right Atrium<br />Connected by a rapid conduction system to the atrio-ventricular node<br />AV nodewhich lies at the base of the interatrial septum. <br />
  92. 92. Electric Circuit of the Heart: AV Node<br />Regarded as the ‘gatekeeper&apos; or resistor in the circuit <br />Tries to maintain normal communications between the atria and ventricles. <br />Connects to the Bundle of His <br />Bundle of His divides into a right bundle, supplying the right ventricle and a<br /> Left bundle, which through its anterior-superior and posterior-inferior divisions supplies the two surfaces of the left ventricle. <br />
  93. 93. Electric Circuit of the Heart <br />
  94. 94. Electrical conduction<br />The electrical conduction through circuits causes a rapid wave of depolarization to spread across the atria and then down through the ventricles. <br />This depolarization and subsequent repolarization is represented by the different waves of the ECG. <br />
  95. 95. Electrical conduction<br />The electrical baseline of the ECG from is known as the iso-electric line.<br />Deflections above this line are POSITIVE <br />Deflections below are NEGATIVE. <br />R wave is positive, <br />S wave is negative<br />A QRS is iso-electric when the addition of the positive and negative deflections give a net deflection of zero. <br />
  96. 96.
  97. 97. EKG Paper<br />Grid where time is measured along the horizontal axis. <br />Each small square is 1 mm in length and represents 0.04 seconds. <br />Each larger square is 5 mm in length and represents 0.2 seconds. <br />
  98. 98. Calculating Heart Rate<br />When the rhythm is regular, the heart rate is 300 divided by the number of large squares between the QRS complexes. <br />For example, if there are 4 large squares between regular QRS complexes, the heart rate is 75 (300/4=75). <br />
  99. 99. Calculating Heart Rate<br />The second method can be used with an irregular rhythm to estimate the rate. <br />Count the number of R waves in a 6 second strip and multiply by 10. <br />For example, if there are 7 R waves in a 6 second strip, the heart rate is 70 (7x10=70). <br />
  100. 100. P Wave<br />First small positive deflection before the QRS complex <br />Atrial depolarization <br />width &lt;0.12 sec<br />
  101. 101. PR Interval <br />Distance from start of P wave to start of QRS complex <br />Conduction time from SAN through the AV node<br />&lt; 0.20 sec<br />
  102. 102. Q Wave <br />First negative deflection after the P wave and before the R wave <br />Represents conduction from the opposite side of the heart <br />
  103. 103. R Wave <br />First positive deflection after the P wave <br />Ventricular depolarization <br />
  104. 104. S Wave <br />First negative deflection after the R wave<br />Ventricular depolarization <br />
  105. 105. QRS Complex <br />Complex including the Q, R and S waves<br />Complete ventricular depolarization <br />&lt;0.12 seconds <br />
  106. 106. ST Segment <br />Segment between the end of the S wave and the start of the T wave<br />First part of ventricular repolarization <br />
  107. 107. T Wave <br />Positive wave after the QRS complex <br />Ventricular repolarization <br />
  108. 108. QT Interval<br />Start of the QRS complex to the end of the T wave<br />Ventricular depolarization and repolarization<br />0.42 seconds <br />
  109. 109. Normal Sinus Rhythm<br />Regular rhythm<br />Heart rate 60 – 100<br />P wave for every ORS, identical<br />PR interval 0.12 – 0.20 second<br />ORS complex 0.06 – 0.10 seconds<br />
  110. 110. Sinus Bradycardia<br />Heart rate &lt; 60<br />Regular rhythm<br />P wave before each ORS, identical<br />PR interval .12 - .20 seconds<br />ORS &lt; .12<br />
  111. 111. Sinus Bradycardia<br />Possible Causes<br />Hyperkalemia<br />Increased vagal tone-constipation, vomiting<br />Inferior wall MI<br />Beta blockers, digoxin, morphine<br />Signs & Symptoms<br />Possibly asymptomatic<br />Fatigue, lightheadedness, syncope, palpitations, chest pain<br />Treatment <br />Treat underlying cause<br />Atropine<br />Pacemaker<br />
  112. 112. Sinus Tachycardia<br />Regular rhythm<br />Heart rate 100 – 160<br />P wave before each ORS<br />PR interval 0.12 – 0.20 second<br />ORS complex 0.06 – 0.10 seconds<br />
  113. 113. Sinus Tachycardia<br />Possible Causes<br />Caffeine, tobacco, ETOH<br />Digoxin toxicity<br />Exercise, fever, stress, pain, dehydration<br />Inflammatory response<br />Hypovolemia<br />Signs & Symptoms<br />Usually asymptomatic<br />Palpitations or angina<br />Treatment<br />Treat underlying cause<br />Beta blockers<br />
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