What occurs during the T wave of an ECG?

During the T wave of an ECG, the heart's ventricular muscle cells are undergoing repolarization, which is the process of restoring the electrical potential across the cardiac cell membranes after depolarization. This is a critical moment in the cardiac cycle as it ensures that the ventricles are reset and ready for the next cycle of depolarization and contraction.

The T wave specifically represents the recovery phase after the ventricles have contracted (during the QRS complex). As the ventricular muscle cells return to their resting state, potassium ions move out of the cells, which causes the cell membranes to repolarize. The duration and shape of the T wave can provide insights into the heart's health and effectiveness of its electrical activity.

Repolarization is essential for preventing premature contractions and for allowing a proper filling of the heart chambers. Understanding the T wave's role in this cycle is crucial in interpreting an ECG and assessing the heart's electrical function.