Ischemic Heart Disease Flashcards
What is angia pectoris? Syx?
Pain of myocardial ischemia; Severe crushing/burning sensation in the substernal portion of the chest and may radiate to left arm, jaw, or epigastrium
What is Prinzmetal angia? Cause?
Atypical form of angina that occurs at rest and may be caused by coronary vasospasm
What is unstable angina? Causes?
Variety of chest pain that has a less predictable relationship to exercise than does stable angina and may occur during rest/sleep; Associated with development of nonocclusive thrombi over athersclerotic plaques
When does stable angina generally occur?
During exertion/exercise
What is a myocardial infarction?
Discrete focus of ischemic muscle necrosis in the heart excluding patchy necrosis caused by drugs/toxins/viruses
What is responsible for heart failure in more than 75% of all patients with heart failure?
Coronary artery disease
What underlies most cases of cardiac death occurring during the first hour after the onset of Syx? What is the general physiological progression starting from ischemia leading to death?
Atherosclerosis of coronary vessels; Ischemia -> Ventricular Tachycardia -> Ventricular Fib -> Death
What is lethal arrhythmia likely triggered by?
Acute ischemia without overt myocardial infarction
What are the 4 major risk factors that predispose to coronary artery disease?
- Systemic hypertension
- Cigarette smoking
- Diabetes mellitus
- Elevated blood cholesterol
At what point is maximal blood flow to the myocardium impaired? When is resting blood flow impaired?
75% of cross-sectional area (50% of diameter) is blocked; 90% of lumen occluded
What does coronary thrombosis usually cause?
Acute myocardial infarction
How common are MI caused by thromboemboli? Where do the thromboemboli generally originate?
Rare; Usually heart valvular vegetations caused by infective or nonbacterial endocarditis
By what mechanism is coronary collateral circulation created? Describe the mechanism of infarction at a distance of the anterior infarction.
Develop in response to coronary athersclerosis; Collateral vessels are formed between the right coronary artery and the left anterior descending artery in response to occlusion of the LAD. Acute blockage of the RCA stops bloodflow through the collateral circultion resulting in anterior infarction
How does syphilitic aortitis cause ischemic heart disease?
By obliterating the coronary artery orifice
Describe the physiology in which ischemic heart disease is caused by an intramural coursing of the LAD
The LAD normally runs in the epicardial fat. Occasionally it passes through the myocardium and can be blocked during systole from the muscle
Describe the scenario in which anemia could cause ischemic heart disease
Anemia alone generally does not affect the heart. With concurrent atherosclerosis, there may be limited compensatory increases in coronary blood flow
Describe how hyperthyroid can lead to ischemic cardiac disease
Hyperthyroid leads to increased metabolic rate and tachycardia and results in increased oxygen demand and greater cardiac workload
What is a subendocardial infarct?
An infarction that affects the inner one third to one half of the left ventricle