Which ECG finding is most indicative of prolonged coronary occlusion?

The presence of a pathologic Q wave on an ECG is considered a significant indicator of prolonged coronary occlusion, typically reflecting an area of myocardial necrosis. When there is a sustained blockage in the coronary arteries, it can lead to a lack of blood flow and oxygen to the heart muscle. This damage can result in the death of heart tissue, which is what pathologic Q waves signify.

Pathologic Q waves are characterized by their depth and duration; they are usually wider and deeper than normal Q waves found in healthy individuals. These waves develop in the leads corresponding to the area of infarction and indicate that a significant portion of muscle has been compromised due to extended ischemia. Therefore, their presence serves as an essential marker in diagnosing myocardial infarction, particularly when analyzing past heart damage tied to acute coronary syndrome.

In contrast to pathologic Q waves, sinus tachycardia, prolonged PR intervals, and fibrillatory P waves are not specific indicators of myocardial necrosis and do not provide the same level of information regarding prolonged coronary occlusion. Sinus tachycardia may occur in various scenarios, including anxiety or dehydration; a prolonged PR interval could indicate first-degree heart block but is not specific to coronary occlusion; and fibrillatory P