Interatrial block: is it time for more attention?

Interatrial block (IAB) is defined as delayed conduction between the right and left atrium, which results in prolonged P-wave duration (≥110 milliseconds). Interatrial block can be partial or advanced (much less common), depending on the severity of the conduction abnormality. Several studies have reported that the prevalence of IAB is more than 40% in hospital inpatients. Despite this, IAB remains largely underdiagnosed and commonly ignored. Although more investigations are needed to identify the cause of IAB, coronary artery disease and conditions related to cardiovascular disease, such as hypertension or diabetes mellitus, have been described as potential risk factors for developing IAB. Interatrial block has strong associations with multiple medical conditions including atrial fibrillation, myocardial ischemia, left atrial enlargement, and systemic emboli. Treatment modalities for IAB to preclude its consequences include pacing and medical management, in which angiotensin-converting enzyme inhibitors and angiotensin receptor blockers have given promising results. However, more interest, attention, and research for IAB is required to explore this uncertain issue thoroughly.