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19 Cards in this Set
- Front
- Back
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What are the 3 general causes of Ischemic Heart Disease (IHD)?
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coronary insufficiency, eg artherosclerosis
Increased myocardial demand hypoxemia |
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What are the 4 classical presentations of IHD, also known as the Acute coronary syndromes?
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angina pectoris
myocardial infarction sudden cardiac death chronic congestive heart failure (chronic IHD) |
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What is sudden cardiac death syndrome (SCD)?
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unexpected death by cardiac causes within one hour of symptom onset
typically involves a lethal arrhythmia, ususally ventricular afibrillation may result from a conducting system anomaly, myocarditis, valvular disease, or most commonly ischemia leads to an MI in 20-30% of cases |
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What types of arteries are most often involved in IHD?
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epicardial arteries
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Describe the most common cause of decreased myocardial flow?
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Artherosclerotic coronary artery disease (CAD)
flow limiting stenosis usuallly occurs w/in first 5 cm of artery chronic narrowing or complete occlusion = artherosclerotic plaque/ fixed stenosis complications occur from acute lesions (thrombotic occlusion, plaque rupture) collateral circulation increases during the disease process, may be newly formed vessels or modified flow |
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What are other causes of decreased coronary flow?
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coronary spasm
embolsim amyloidosis coronary vasculitis spasm is associated with variant (Prinzmetal's) angina |
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When does IHD occur?
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when myocardial O2 demands meet supply
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What would cause the myocardial O2 demand to meet supply?
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Reduction in coronary flow
increased myocardial O2 demand b/c of tachycardia, hypertension, hypoxemia |
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How does coronary artery pathology correlate with the 4 clinical presentations of IHD?
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most people who survive IHD have coronary artey artherosclerosis and an acute coronary lesion
fixed stenoses is associated with angina pectoris plaque ruptures and non occlusive thrombi are associated with "crescendo angina" Acute MI is associated with occlusive thrombi |
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What are the morphological patterns of Ishemic myocardium?
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Transient Ischemia: contraction band, necrosis, often with hemorrhage; seen in reperfusion injury
Prolonged Ischemia: Myocardial infarction Chronic and/or gradual Ischemia: myocytolysis and fibrosis, may include old infarcts, typical pathology of IHD (ischemic cardiomyopathy) |
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What are the funcxtional changes that occur in an ischemic myocardium?
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arrythmia and cassation of conduction
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How is diagnosis of MI made?
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history
ECG findings lab studies (serum markers) |
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What are general characteristics of Myocardial Infarction?
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most important cause of morbidity from IHD
characterized by myocardial coagulative necrosis caused by coronary artery occlusion marked by series of progressive gross and microscopic changes and release of myocardial nzms and protiens into bloodstream cells involved include neutrophils, macrophages, and fibroblasts |
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What are the 2 distinct patterns of MI?
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Transmural: myocardial necrosis that traversis the entire ventricualr wall from endocardium to epicardium
- us. associated with coronary occlusions Subendocardial: myocardial necrosis that is limited to the interior one third of the wall of the left ventricle circumfrential, usually result of reopened infarct related artery |
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What is a paradoxial infarct?
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infarcts NOT in area supplied by occluded artery
occur b/c of loss of colateral circulation |
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What is the mechanism of muscle cell loss in MI?
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apoptosis
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What complications are assocaited with MI?
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myocardial stunning; transiently non functional but viable myocardium, esp associated with reperfusion
arrythmia andcongestive failure - most common cause of death in first hours Cardiogenic Shock - due to myocardial pump failure pumonary embolism myocardial rupture - usually occurs w/in 4-7 days may result in death from cardiac tamponade mural and periphaeral thrombosis |
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Treatment of cardiac ischemia with reperfusion is often associated with distinctive pathologic anatomy. Give examples of this.
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thrombolysis --> hemmorhagic infarction, contraction bands
PTCA --> Acute = plaque hemmorhage, dissection, thrombosis, rupture Subacute = restenosis Coronary artery bypass graft -->graft artherosclerosis, fibrointimal hyperplasia modulation of platelet function and reductions of risk factors --> ??? |
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What serum markers are specific for MI?
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CK-MB
contractile proteins: cardiac troponin troponin I all rise approx 12 hours after MI but stay elevated for 4-7 days |
