ANSWERS WITH COMPLETE SOLUTIONS
coronary circulation during rest
4-5% of cardiac output
coronary circulation during stress
10-15% of cardiac output
T/FL blood flow through coronary arteries occurs primarily during diastole
True
wha are the determinants of oxygen demand?
1. heart rate
2. contractility
3. preload, afterload
what are the determinants of oxygen supply?
1. coronary patency
2. diastolic BP
3. blood O2 capacity
4. collateral circulation
ischemic heart disease
-oxygen demand > supply
-increased HR, contractility, preload, and afterload
-decreased coronary blood flow leading to vasospasm, fxied stenosis/atherosclerosis,
, and thrombus
-leads to hypoxia --> angina ---> MI --> arrhythmias --> and sudden death
angina pectoris
-typical (stable)
-variant (prinzmetal)
-atypical (unstable)
Typical stable (angina) pectoris
1. fixed atherosclerotic narrowing
2. heavy substernal discomfort
3. nitroglycerin, B-adrenergic receptor antagonists
variant (prinzmetal) angina pectoris
1. coronary vasospasm
2. discomfort at rest
3. calcium channel blockers
atypical (unstable) angina pectoris
1. atherosclerotic plaque rupture, thrombosis
2. discomfort with stress or rest
3. anticoagulants, anti-platelet drugs
Drug classes that treat angina
-nitrates: nitroglycerin, isosorbide mono and dinitrate
-beta AR antagonists: metoprolol
-calcium channel blockers: verapamil, diltiazem, nifedipine
-Na channel inhibitor: Ranolazine