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 P ...

What Is a Normal Sinus Rhythm? Normal sinus rhythm is when your heart beats in a regular, organized way. Your body has a built-in pacemaker called the sinoatrial (SA) node, or sinus node. It uses ...

Junctional rhythm is an irregular heart rhythm that stems from a natural pacemaker in the heart known as the atrioventricular junction. The heart has several built-in pacemakers that help control its ...

A premature atrial contraction occurs when a focus in the atrium (not the sinoatrial node) generates an action potential before the next scheduled SA node action potential. There are four main ...

What is Sick Sinus Syndrome (SSS)? Sick sinus syndrome is not a disease condition but a clinical syndrome that is related to the sinoatrial node (SA node). It is also referred to as sinus node disease ...