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 ...

A sinus arrhythmia refers to a problem with the sinus node of the heart. This controls the rhythm of the heart and can be fast (sinus tachycardia) or slow (sinus bradycardia). This article looks at ...