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Updated: Oct 28, 2026

A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation
Published on: February 28, 2012
His Bundle Pacing via the Atrial Port of a Dual-Chamber ICD: Programming Solution for Undersensing
Thai Duy Vo1, Le Uyen Phuong Tran1,2, Thi Van Khanh Nguyen3
1Department of Arrhythmology, Cho Ray Hospital, Ho Chi Minh city, Vietnam.
Background:
His-bundle pacing connected to the atrial port of a dual-chamber ICD may lead to sensing failure and unsafe pacing.
Case Summary:
A 67-year-old man with permanent atrial fibrillation, alternating rapid and slow ventricular rates despite medication, symptomatic pauses longer than 6s, and a dual chamber ICD (His lead in the RA port; DF4 lead in the RV port) presented with palpitations. ECG and 24-hour Holter demonstrated intermittent His-channel undersensing with pacing on the T-wave peak. Interrogation showed small His electrograms followed by a prominent, constant ventricular far-field signal on the atrial channel. We turned off far-field protection after V-sense, intentionally used the ventricular far-field signal for sensing of His lead, and disabled related discrimination algorithms.
Conclusion:
A dual-chamber ICD with a His-bundle pacing lead may be associated with complex programming challenges, and targeted reprogramming can avoid lead revision or reimplantation.
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