What does the ST-segment in an ECG indicate?

The ST-segment in an ECG represents the interval between ventricular depolarization and repolarization. This segment begins at the end of the QRS complex (which indicates depolarization) and ends at the start of the T wave (which indicates repolarization).

The significance of the ST-segment lies in its use for diagnosing various cardiac conditions. An elevated or depressed ST-segment can indicate issues such as ischemia (insufficient blood flow to the heart) or myocardial infarction (heart attack). In a healthy heart, the ST-segment is typically flat and at baseline. Changes in this segment can provide crucial information about cardiac health and prompt further investigation or intervention.

Understanding this interval is essential for interpreting ECGs correctly, as it directly reflects the recovery phase of the heart's electrical cycle. This context is fundamental when evaluating patients for potential cardiac issues.