What is myocardial ischemia?

Myocardial ischemia refers to a condition where there is an insufficient blood flow to the heart muscle, which limits the supply of oxygen and nutrients that the heart requires to function effectively. This typically occurs due to narrowed or blocked coronary arteries, often as a result of atherosclerosis, a condition characterized by the buildup of plaque in the artery walls. When the heart muscle does not receive adequate blood supply, it can lead to symptoms such as chest pain or angina and, in more severe cases, can result in a heart attack.

The other options describe different cardiovascular conditions or phenomena. An increase in oxygen supply to the heart muscle does not define ischemia; rather, it would be a beneficial state for heart function. A type of heart valve disease refers to issues related to the valves that direct blood flow through the heart but does not encompass ischemia. An abnormal heart rhythm, or arrhythmia, pertains to irregular heartbeats that can occur for various reasons but is also distinct from the concept of ischemia. Understanding these distinctions is crucial in cardiovascular health and management.