Idioventricular Rhythm: Electrophysiological Mechanisms, Clinical Recognition, and Contemporary Management Perspectives

Idioventricular rhythm represents a slow, regular ventricular rhythm that emerges when higher-order cardiac pacemakers fail or are suppressed, permitting latent ventricular foci to assume the role of dominant pacemaker. Characterized by a rate typically below 50 beats per minute, absence of P waves, and a prolonged QRS interval, this rhythm exists along a continuum with accelerated idioventricular rhythm (AIVR), which occupies the intermediate rate range of 50 to 110 beats per minute. The electrophysiological basis of these rhythms involves abnormal calcium-dependent automatism affecting phase 4 diastolic depolarization, with triggered activity serving as the principal arrhythmogenic mechanism in digitalis toxicity. Etiological factors are diverse and include advanced or complete heart block, reperfusion following myocardial infarction, electrolyte disturbances, pharmacological agents, and, rarely, congenital heart disease or cardiomyopathies. Most patients remain asymptomatic, and the rhythm is typically identified during cardiac monitoring. Electrocardiography with clinical correlation remains the cornerstone of diagnosis. Management is predominantly conservative, focusing on the underlying causative etiology rather than suppression of the rhythm itself. The prognosis is generally favorable, with spontaneous resolution occurring when sinus frequency exceeds that of the ventricular focus. However, sustained or incessant forms associated with atrioventricular dissociation and syncope warrant therapeutic intervention. This review synthesizes current understanding of idioventricular rhythm and AIVR, emphasizing their electrophysiological foundations, clinical significance, and the importance of interprofessional care coordination in optimizing patient outcomes.