Iranian Journal of Medical Sciences

Document Type: Review Article


1 Department of Medicine, Steward Carney Hospital, Boston, MA, USA

2 Department of Medicine, Division of Cardiology, St. Vincent Hospital and University of Massachusetts Medical School, Worcester, MA, USA


Interatrial block (IAB) denotes a conduction delay between the two atria (P-wave duration ≥110 ms). Depending on the severity of the block, IAB can be partial or advanced. Even though several studies have reported a high prevalence of IAB, it still remains a diagnosis many neglect without any follow-up. The crisis in IAB is undramatic until predictable complications appear. Nevertheless, the danger in IAB is real because of the major associations with multiple medical conditions, including atrial fibrillation, myocardial ischemia, left atrial enlargement, and systemic emboli. There are different treatment options for IAB to eliminate its consequences, including pacing and medical management with angiotensin-converting enzyme inhibitors and angiotensin receptor blockers. Pacing has been shown to give promising results and could potentially prevent conditions related to cardiovascular disease such as hypertension or diabetes mellitus. Given the high prevalence of IAB, together with its potentially serious consequences, and yet being largely ignored, we stress attention to this potentially dangerous pandemic and raise consideration for further investigations.