Heart Depolarization and Repolarization Diagram

This diagram beautifully illustrates the intricate relationship between the electrical activity of the heart and its representation on an electrocardiogram (ECG). It breaks down a single heartbeat cycle, showing how electrical impulses spread and then reset within the cardiac muscle. The top part displays a typical ECG waveform with six numbered segments. Below, six corresponding heart diagrams reveal the progression of electrical events. Orange areas indicate depolarization, which is the electrical activation leading to muscle contraction. Green areas represent repolarization, the electrical recovery phase where the muscle cells return to their resting state, preparing for the next beat. The sequence begins with the P wave (segments 1 and 2), showing the depolarization of the atria as blood is pumped into the ventricles. Next, the prominent QRS complex (segments 3 and 4) depicts the rapid depolarization of the ventricles, leading to their powerful contraction to pump blood out to the body and lungs. Finally, the T wave (segments 5 and 6) illustrates the repolarization of the ventricles, as they relax and refill with blood, completing the cycle and readying the heart for its next beat.

heart - ecg - depolarization - repolarization - cardiac cycle - electrocardiogram - anatomy