During a heart attack, which area is primarily affected when blood flow is blocked?

The myocardium is the thick, muscular layer of the heart wall responsible for regulating the heartbeat and pumping blood throughout the body. During a heart attack, which is often caused by a blockage of blood flow to the coronary arteries, the myocardium is primarily affected. When these arteries are blocked, the myocardium does not receive the oxygen and nutrients it needs, leading to ischemia and potential damage to the heart muscle itself.

In contrast, the pericardium is the protective sac surrounding the heart, the endocardium is the inner lining of the heart chambers, and the epicardium is the outermost layer of the heart wall. While these structures are essential for overall heart function, they are not the primary areas at risk when blood flow is compromised during a heart attack. Thus, the focus on the myocardium as the area impacted highlights its crucial role in heart health and the serious consequences of reduced blood supply in this part.