Ischemic Heart Disease for the USMLE
ISCHEMIC HEART DISEASE
- Stable Angina
- Unstable Angina
- Variant Angina (Prinzmetal’s)
Fixed atherosclerotic lesions narrow the coronary arteries, leading to an imbalance between blood supply and 02 demand. This leads to inadequate perfusion, and oxygen demand exceeds blood supply. Atherosclerosis leads to narrowing > 75%.
– Substernal chest pain lasting less than 15 minutes
– Pain is described as squeezing, heaviness, pressure
– Always brought on by physical exertion
– Pain goes away with rest and/or nitroglycerine
In unstable angina, the cause of chest pain is due to a reduced resting coronary blood flow. The main difference between unstable vs. stable angina is that the pain of unstable angina occurs at rest.
Prinzmetal’s angina is caused by a transient coronary vasospasm that is accompanied by a fixed atherosclerotic lesion. The symptoms occur at rest.
– Chest pain at rest
– Most common in younger females who smoke cigarettes
– There will be a transient ST-segment elevation on EKG during the episodes of chest pain