ECG Lead System Practice Test 2025 - Free ECG Practice Questions and Study Guide

An inverted T wave in an ECG is a significant finding that can potentially indicate myocardial ischemia. The T wave represents the repolarization phase of the heart's ventricles; therefore, its inversion often suggests that there may be an underlying issue affecting the heart muscle. Myocardial ischemia occurs when blood flow to the heart muscle is reduced, which can affect how the heart repolarizes after each heartbeat.

When the heart experiences ischemia, the electrical activity is altered, leading to changes in the T wave morphology. An inverted T wave, particularly when seen in leads that correlate with territories supplied by specific coronary arteries, can signal that there is insufficient blood flow, potentially due to obstructions or narrowed coronary arteries.

In contrast, the other choices relate to conditions that do not typically present with an inverted T wave. Normal heart function would normally show upright T waves, atrial enlargement generally affects the P wave, and ventricular hypertrophy may lead to other changes such as increased amplitude of the QRS complex rather than T wave inversion. Thus, the presence of an inverted T wave serves as a clinical clue pointing more towards myocardial ischemia than other cardiac conditions.