Ischemic Heart Disease I Flashcards
Diabetes and insulin resistance are associated with inflammation, oxidative stress, and dyslipidemia that predispose to _______.
atherosclerosis
In the normal coronary circulation, autoregulation provides protection from _____.
moderate changes in perfusion pressure
_____ are associated with inflammation, oxidative stress, and dyslipidemia that predispose to atherosclerosis.
Diabetes and insulin resistance
When is the LV perfused?
diastole only
Factors that increase myocardial O2 demand?
- HR 2. wall tension 3. inotropic state
An _____ causes a drop in perfusion pressure.
epicardial coronary stenosis
Tachycardia can compromise ______.
coronary flow
Oxygen delivery (mol/min) = coronary flow rate (ml/min) x _______
arterial oxygen content (mol O2/ml blood)
What is a reperfusion injury?
early reperfusion that can provoke an additional injury
______ = coronary flow rate (ml/min) x arterial oxygen content (mol O2/ml blood)
Oxygen delivery (mol/min)
How is O2 supply increased in chronic stable angina treated?
prevent HTN, give beta blockers, vasodilators, coronary angioplasty or bypass surgery, treat anemia and hypoxemia
Oxygen delivery (mol/min) = ______ x arterial oxygen content (mol O2/ml blood)
coronary flow rate (ml/min)
Smoking confers a 50% increase in ___ risk.
CAD
How is O2 demand reduced in chronic stable angina?
antihypertensive drugs, rate slowing drugs (beta-blockers, Ca++ channel blockers, limit preload (diuretics, nitrates), negative inotropes (beta blockers, Ca++ channel blockers)
Oxygen supply may be compromised by ____ or ____.
anemia; hypoxemia
What is the cardinal symptom of an MI?
severe and unremitting chest discomfort at rest (although 30% of MI’s are “silent”)
In coronary heart disease, autoregulation may be exhausted when ______ across an epicardial coronary stenosis.
pressure drops
When is troponin elevated?
in an acute MI
What causes unstable angina?
Near-complete occlusion of vessel with thrombus
What is different about the coronary circulation?
- the myocardium depends on aerobic metabolism for energy supply 2. Under resting conditions, a near-maximal amount of oxygen is extracted from coronary arterial blood; therefore, the only effective means of increasing myocardial O2 supply is to increase blood flow rate 3. the LV is perfused in diastole only
What attributes to a fatty streak?
endothelial injury lipid deposition mac and T cell recruitment
______ limits coronary flow and cause myocardial ischemia (tissue blood flow insufficient to meet oxygen requirements), particularly when cardiac work and oxygen demand increase.
Obstructive coronary lesions
______ (dental, respiratory, immunologic diseases) may also increase the risk of atherosclerotic cardiovascular events.
Extravascular inflammation
Autoregulation occurs at the level of _____.
the small arterioles