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 ...

[1] Bradycardia or bradyarrhythmia in adults may be considered present if the heart rate is <60 beats/min in the setting of sinus rhythm, a variety of atrial rhythms, including slow atrial ...

and prolonged sinus pauses after AF termination, which is also known as tachycardia-bradycardia syndrome. When antiarrhythmic drugs (AADs) are administered for rhythm or ventricular rate control ...