Self Study

Question 1

What factors are important in determining the size of a myocardial infarct?

Answer 1

degree of collateral blood flow
duration and severity of the occlusion / ischemia
metabolic demand of the myocardium
systemic vascular perfusion (e.g., blood pressure)
effectiveness of therapy

Question 2

How long after the onset of ischemia does a myocardial infarct become grossly apparent? Histologically apparent?

Answer 2

grossly: 12-24 hours
histologically: 4-12 hours

Question 3

What are some causes of myocardial ischemia that are NOT related to epicardial coronary artery atherosclerotic occlusion?

Answer 3

1. coronary artery vasospasm (e.g., Prinzmetal angina, cocaine abuse)
2. coronary artery diseases other than atherosclerosis (e.g., embolism, vasculitis)
3. supply / demand imbalance (e.g., severe systemic hypotension, aortic stenosis, cardiomyopathies, tertiary syphilis of the aorta, coronary artery congenital anomalies)

Question 4

What conditions are known to predispose to infective endocarditis?

Answer 4

1. pre-existing valvular abnormalities
2. prosthetic heart valves
3. congenital heart disease
4. immunodeficiency states
5. intravenous drug abuse

Question 5

What complications are likely to cause death in infective endocarditis

Answer 5

sepsis secondary to bacterial endocarditis; acute mitral regurgitation (e.g., secondary to a perivalvular ring abscess); arrhythmia