How many deflections (waves) form a complete heartbeat on an EKG?

A complete heartbeat on an electrocardiogram (EKG) consists of a series of distinct deflections that illustrate the electrical activity of the heart. In a typical EKG tracing, there are five identifiable waves or deflections that correspond to different phases of cardiac activity.

First, there is the P wave, which represents atrial depolarization as the atria contract to push blood into the ventricles. Following this, the QRS complex, which consists of three individual deflections (the Q wave, R wave, and S wave), represents ventricular depolarization. This complex signifies that the ventricles are contracting to pump blood out of the heart. Lastly, the T wave represents ventricular repolarization, which is when the ventricles recover and prepare for the next heartbeat.

The sum of these waves gives a total of five deflections—one P wave, three waves in the QRS complex, and one T wave—resulting in a complete picture of the heart’s electrical activity during a heartbeat. Recognizing these five distinct waves is crucial for monitor technicians, as it helps them assess heart rhythms and detect abnormalities.