Technologist Track Session 3: Ischemic Heart Disease (2019)-Ischemia physiology

Video Transcription

Video Summary

The transcript explains myocardial ischemia as reduced blood flow to the heart, usually from coronary artery atherosclerosis. It emphasizes the key supply-demand balance: ischemia occurs when oxygen supply cannot meet myocardial demand, especially during exercise or other stress. The talk reviews the ischemic cascade, where perfusion defects appear first, followed by wall motion abnormalities, ECG changes, and finally symptoms like angina. It also describes positive remodeling, in which arteries enlarge to hide plaque until stenosis becomes severe. The coronary microcirculation and coronary flow reserve help maintain resting flow despite blockage. Acute coronary syndromes are contrasted with stable disease, showing how vulnerable plaque rupture can suddenly cause thrombosis and infarction. Finally, it explains fractional flow reserve (FFR) and FFR-CT as tools to determine whether a stenosis is truly ischemic, helping guide decisions about stenting versus medical treatment.

Keywords

myocardial ischemia

coronary artery atherosclerosis

ischemic cascade

fractional flow reserve

acute coronary syndromes