Sinoatrial exit block occurs when the action potential initiated by the sinoatrial node is inhibited or completely blocked before it is able to leave the SA node and reach the atrium, and thus no ...

First, the sinoatrial, or SA, node sets your “resting” heart rate, usually somewhere between 60 and 100 beats per minute.

When the patient's heart was removed, a portion of the right atrium was left behind including the native sinoatrial node (SA node). A new heart was implanted which also included a SA node.