Where do atrial rhythms originate from?

Atrial rhythms typically originate from ectopic sites within the atria. These sites are areas of cardiac tissue in the atria that generate electrical impulses independently of the primary pacemaker, which is the sinoatrial node. When these ectopic foci take over the pacing responsibility, it can lead to various types of atrial arrhythmias, such as atrial fibrillation or atrial flutter.

Understanding ectopic atrial rhythms is crucial because they can affect heart rate and rhythm significantly, leading to clinical implications that require careful management. In contrast, rhythms originating from the sinoatrial node would be considered normal sinus rhythm, while those from the atrioventricular node or ventricular pacemaker sites would indicate a different, often less favorable, cardiac condition.