What is a potential sign of myocardial infarction detected during an ECG?

A potential sign of myocardial infarction detectable during an ECG is an elevated ST segment. This phenomenon, known as ST-segment elevation, indicates that there is an acute injury to the heart muscle, which occurs when there is a blockage in one of the coronary arteries. This blockage restricts blood flow, resulting in ischemia and subsequent damage to cardiac tissue. The elevation reflects the impact of this injury on the electrical activity of the heart, specifically during the phase of depolarization.

In contrast, a normal P wave pattern would indicate that the atria are depolarizing normally, while a decreased heart rate does not specifically correlate with myocardial infarction and can be influenced by various factors. A flat QRS complex could suggest an abnormality in ventricular conduction, but it is not a definitive indicator of myocardial infarction like an elevated ST segment is. Thus, ST-segment elevation serves as a clear and critical marker for diagnosing acute myocardial infarction on an ECG.