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Flashcards in Ischemic Heart Disease Deck (19)
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1

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.

2

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.

3

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

4

risk factors for ischemic heart disease

• Hyperlipidemia • Smoking • Hypertension • Diabetes

5

syndromes of ischemic heart disease

• Angina pectoris • Myocardial infarct • Chronic ischemic heart disease • Sudden cardiac death

6

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

7

atherosclerotic coronary artery disease

•disease of the arterial system characterized by focal thickening of the inner portions of the arterial wall - plaques or atheromas

8

atherogenesis

•atherogenesis is believed to be the result of endothelial damage

9

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.

10

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

11

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

12

why is the layer lining the ventricle spared?

•it is exposed to the blood in the ventricles

13

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

14

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

 

15

•subacute infarct

•dead tissue being gobbled up

16

•mature fibrosis

•blue = fibrous tissue

•remaining muscle fibers hypertrophy to compensate

•patchy fibrosis (> 1 cm)

•confluent fibrosis

17

complications of MI

• Sudden death

• Cardiogenic shock

• Cardiac rupture

• Pericarditis

• Ventricular aneurysms

• Mural thrombi

• Arrhythmias

18

chronic myocardial ischemia

•myocyte vacuoles (myocytolysis)

•delicate interstitial fibrosis

•patchy fibrosis (<1 cm)

19

sudden cardiac death

• Often the first manifestation of cardiac disease

• By far, the most common cause is IHD

• Mechanism is thought to be the development of a lethal arrhythmia

• Most patients who survive an out of hospital arrest do not go on to develop an MI

•critical coronary atherosclerosis is present and commonly involves two or three of the major epicardial arteries

•in only 25 % of cases is an acute myocardial infarct detected, in most chronic subendocardial ischemia and old infarcts are present