Sinus Rhythm

Sinus rhythm is referred to as the “normal” heart rhythm. It represents the pattern of electrical activity that is seen on an electrocardiogram (ECG or EKG) when the heart is beating normally. An ECG is a routine test that records the electrical activity of the heart, using electrodes placed on the surface of the skin. A normal ECG has identifiable waves in each cycle that are named the P wave, QRS complex, and T wave. The P wave is associated with activity in the atria (upper chambers of the heart); the QRS and T wave are associated with activity in the ventricles (lower chambers of the heart).

The electrical system of the heart is made up of several parts that communicate with one another to signal the heart muscle fibers to contract. The impulse is initiated by the sinoatrial node (SA node) which is located in the right atrium. The electrical impulse travels through the atria (causing them to contract) to the AV node and on through the bundle of His and the bundle branches located within the ventricles which causes the ventricles to contract. This flow of electrical signals produces a normal heartbeat or normal heart rhythm called “sinus rhythm.”


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