Atrial escape beat and atrial escape rhythm

When sinus impulse conduction is inhibited (such as in sinus bradycardia, sinoatrial block, or sinus arrest), if the automaticity of atrial latent pacemakers is higher than that of the sinus pacemaker, or if sinus impulses fail to conduct, the atrial pacemaker can take control of the atria, producing atrial escape beats. When the factors inhibiting the sinoatrial node disappear, sinus rhythm returns and atrial escape beats disappear. Therefore, atrial escape beats represent a physiological compensatory mechanism. Three or more consecutive atrial escape beats constitute an atrial escape rhythm.