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Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System

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Biventricular pacing and QT interval prolongation.

Atul Bhatia¹, Vikram Nangia, Joaquin Solis

¹Electrophysiology Laboratories of Aurora Sinai/St. Luke's Medical Centers, University of Wisconsin Medical School-Milwaukee Clinical Campus, Milwaukee, Wisconsin, USA. bdanek@hrtcare.com

Journal of Cardiovascular Electrophysiology

|April 25, 2007

Summary

Biventricular pacing in heart failure patients prolongs the QT interval, potentially increasing arrhythmia risk. However, serious arrhythmias like torsade de pointes remain uncommon with this therapy.

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Optimization of Transesophageal Atrial Pacing to Assess Atrial Fibrillation Susceptibility in Mice

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Area of Science:

Cardiology
Electrophysiology
Heart Failure Management

Background:

Biventricular pacing (BiV) is a key therapy for advanced congestive heart failure (CHF) and bundle branch block (BBB).
Understanding BiV pacing's effects on cardiac electrophysiology is crucial for patient safety.
The potential for proarrhythmia, particularly QT interval prolongation, requires investigation.

Purpose of the Study:

To assess changes in QT interval duration due to BiV pacing.
To evaluate the risk of proarrhythmia associated with BiV pacing in CHF patients.

Main Methods:

Studied 176 patients with ischemic or non-ischemic cardiomyopathy (NYHA Class II/III CHF).
Patients underwent atrial synchronous BiV pacing.
QRS, QT, and JT intervals were measured at baseline, 30 minutes, 24 hours, and 1 month post-implant.

Main Results:

BiV pacing significantly reduced QRS duration (148 ms vs. 178 ms).
BiV pacing significantly prolonged the QT interval (470 ms vs. 445 ms).
One patient experienced torsade de pointes, which resolved upon discontinuation of left ventricular pacing.

Conclusions:

Biventricular pacing leads to a significant prolongation of the QT interval.
Despite QT prolongation, the incidence of torsade de pointes is infrequent in patients undergoing BiV pacing.