How common is interatrial block?

Interatrial block is not that common in the general population. In the Atherosclerosis Risk in Communities (ARIC) study involving 14,625 patients, interatrial block was detected in 0.5% at baseline and 1.3% developed interatrial block during a follow up of about 6 years. The study showed that interatrial block was associated with increased risk of atrial fibrillation with a hazard ratio of 3.09 [1]. Bayes Syndrome is third degree interatrial block with paroxysmal supraventricular arrhythmias [2]. There is association with increased risk of ischemic stroke and cardiac death. Interatrial block has been shown to correlate directly with structural remodeling and a decrease in the absolute value of strain rate during left atrial booster pump function and early reservoir period determined using speckle tracking echocardiography [3].

References

1. O’Neal WT, Zhang ZM, Loehr LR, Chen LY, Alonso A, Soliman EZ. Electrocardiographic Advanced Interatrial Block and Atrial Fibrillation Risk in the General Population. Am J Cardiol. 2016 Jun 1;117(11):1755-9. doi: 10.1016/j.amjcard.2016.03.013. Epub 2016 Mar 18. PMID: 27072646; PMCID: PMC4898264.
3. Adrian Baranchuk, Pelayo Torner, Antoni Bayés de Luna. Bayés Syndrome – What Is It? Circulation. 2018;137:200-202.
4. Lacalzada-Almeida J, Izquierdo-Gómez MM, Belleyo-Belkasem C, Barrio-Martínez P, García-Niebla J, Elosua R, Jiménez-Sosa A, Escobar-Robledo LA, Bayés de Luna A. Interatrial block and atrial remodeling assessed using speckle tracking echocardiography. BMC Cardiovasc Disord. 2018 Feb 21;18(1):38. doi: 10.1186/s12872-018-0776-6. PMID: 29466939; PMCID: PMC5822665.