Ischemic Heart Disease Flashcards
ischemia
•Ischemia or ischemia is a restriction in blood supply to tissues, causing a shortage of oxygen that is needed for cellular metabolism (to keep tissue alive). Ischemia is generally caused by problems with blood vessels, with resultant damage to or dysfunction of tissue.
infarct
•obstruction of the blood supply to an organ or region of tissue, typically by a thrombus or embolus, causing local death of the tissue.
ischemic heart disease
•The result of an imbalance between supply and demand •Demand influenced by heart mass and heart rate •Supply influences include vessel disease and perfusion pressure
risk factors for ischemic heart disease
• Hyperlipidemia • Smoking • Hypertension • Diabetes
syndromes of ischemic heart disease
• Angina pectoris • Myocardial infarct • Chronic ischemic heart disease • Sudden cardiac death
coronary heart disease
•often a strong correlation with ischemic heart disease •there is no strong correlation between the extent or severity of coronary artery disease and the various syndromes •atherosclerotic •non atherosclerotic
atherosclerotic coronary artery disease
•disease of the arterial system characterized by focal thickening of the inner portions of the arterial wall - plaques or atheromas
atherogenesis
•atherogenesis is believed to be the result of endothelial damage
acute plaque change
•The syndromes of ischemic heart disease do, however, vary with respect to complications of atheromatous plaques resulting in acute plaque change. Acute plaque change is typically associated with the acute coronary syndromes of unstable angina, acute myocardial infarct, and sudden death.
angina pectoris
- By definition, related to ischemia but not infarction
- Substernal or precordial chest discomfort, not the more severe pain of an MI
- Often described as an unpleasant sensation
- Typical adjectives are pressing, squeezing, constricting, choking, bursting, burning, strangling
- May radiate to shoulders, extremities, neck, jaw, teeth
- Stable
- Unstable
- severe atherosclerosis of two or three major coronary arteries, acute plaque change and thrombosis are rare except with unstable type
- subendocardium is frequently the site of focal ischemia, usually without an acute infarct (except in some cases of unstabel angina), old infarcts may be present
-pre-infarct
• Prinzmetal’s
- vasospasm
- atypical
- unpredictable
myocardial infarction
• Subendocardial
-more susceptible
• Transmural
- ST elevated
- acute coronary thrombosis
- atherosclerosis of two or three of the major arteries
- since the LV compromises the major muscle mass of the heart, this chamber is almost exclusively involved by myocardial infarction
- healing is by organization in the form of garnulation tissue with scar formation
why is the layer lining the ventricle spared?
•it is exposed to the blood in the ventricles
aging the infarct
- Inflammation and repair follow the development of myocardial necrosis
- Myocardium does not regenerate
- With loss of myocardium there is often compensatory myocyte hypertrophy
acute myocardial infarct
- red and dead - myocyte eosinophilia
- neutrophils and/or macrophages
- thin wavy fibers
- sarcoplasmic contraction bands
- loss of cross striations
- loss of nuclear staining
- subacute infarct
- dead tissue being gobbled up
- mature fibrosis
- blue = fibrous tissue
- remaining muscle fibers hypertrophy to compensate
- patchy fibrosis (> 1 cm)
- confluent fibrosis
chronic myocardial ischemia
- myocyte vacuoles (myocytolysis)
- delicate interstitial fibrosis
- patchy fibrosis (<1 cm)
