Anything that changes the structure or function of the SA node can lead to sick sinus syndrome, including certain medications, underlying health conditions, and aging. 2 An estimated 1 in 600 ...

First, the sinoatrial, or SA, node sets your “resting” heart rate, usually somewhere between 60 and 100 beats per minute. This is the base effort needed to circulate enough blood to sustain ...

The sinoatrial (SA) node is a mass of tissue located above the right upper chamber (atria) of the heart. It uses electrical signals to help control a person’s heartbeat.

Sinus arrhythmia requires some background information on the heartbeat rhythm. The heartbeat is regulated by a natural pacemaker known as the Sinoatrial (SA) node, situated in the right atrium.