The rhythm is either sinus rhythm or not sinus rhythm. Sinus rhythm refers to the origination of the electrical activity coming from the sinus node — also known as the sinoatrial node ...

Sinus rhythm (a.k.a. normal sinus rhythm) refers to the normal heart beat originating from the sinoatrial node. This is manifested as an upright P wave in lead II of the ECG. Sinus bradycardia ...