What is ventricular depolarization?

Ventricular depolarization refers to the electrical activation of the ventricles of the heart, which causes them to contract and pump blood to the rest of the body. This process is initiated by the depolarization of the ventricular muscle cells, which occurs when ions such as sodium, potassium, and calcium flow in and out of the cells, changing the electrical charge inside the cells.

Ventricular depolarization is represented on an electrocardiogram (ECG) as the QRS complex, which is a waveform that reflects the depolarization of the ventricular muscle cells. The Q wave represents the initial depolarization of the interventricular septum, while the R wave represents the major depolarization of the ventricles. The S wave represents the end of depolarization as the electrical activity spreads upward from the apex of the heart.

Abnormalities in ventricular depolarization can indicate various cardiac conditions, such as bundle branch block, ventricular hypertrophy, or myocardial infarction.