Iranian Heart Journal

Iranian Heart Journal

Atrial High-Rate Episodes and Their Association With Interatrial Block in Dual-Chamber Pacemaker Recipients

Document Type : Original Article

Authors
Mostafa Abdelmonaem
Ayman Mortada
Aly Medhat
John Kamel
Department of Cardiology, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
Abstract
Background: In the era of cardiac pacing, atrial lead placement has enabled continuous monitoring of atrial electrical activity, including atrial high-rate episodes (AHRE). Once considered an incidental finding, AHRE has now emerged as a significant risk factor for thromboembolic events.
 
Methods: This study involved 250 patients who visited the pacemaker interrogation clinic for routine follow-up after dual-chamber pacemaker implantation. ECG analysis assessed P-wave morphology and duration as predictors of interatrial block (IAB). Further, atrial lead interrogation was performed to detect AHRE.
 
Results: Among the 250 patients studied, 65 exhibited IAB: 54 had partial IAB, while 11 presented with complete IAB. The mean P-wave duration was 104.04 ± 15.92 milliseconds (range: 80–140 ms). P-wave morphology in lead II was upright in 239 patients (95.6%) and bimodal in 11 patients. Per ESC guidelines, AHRE was defined as lasting > 5 minutes. Forty-five patients developed AHRE, with a median duration of 7 minutes (range: 5–30 min) and a mean rate of 187.53 ± 23.59 beats per minute (range:110–231 bpm). A strong association was observed between P-wave duration and AHRE incidence. Of the 45 patients with AHRE, 33 (73.3%) had partial IAB, 6 (13.3%) had complete IAB, and 6 (13.3%) displayed normal P-wave morphology and duration.
 
Conclusions: The detection of AHRE via dual-chamber pacemakers showed a significant association with IAB. Both IAB and AHRE were strongly linked to older age and comorbidities, including diabetes, hypertension, and ischemic heart disease. (Iranian Heart Journal 2025; 26(3): 69-78)
Keywords
Thromboembolism
Arrythmia
Atrial fibrillation
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Iranian Heart Journal
Volume 26, Issue 3
Summer 2025
Pages 69-78