Arrhythmic Risk in Biventricular vs. Left Bundle Branch Area Pacing

Quick Takes

  • In this large multicenter cohort study, left bundle branch area pacing was associated with a significantly lower incidence of sustained VT, VF, or new-onset AF compared with biventricular pacing in patients undergoing CRT.

Study Questions:

Is there a difference in the occurrence of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) and new-onset atrial fibrillation (AF) between patients undergoing biventricular pacing (BVP) versus left bundle branch area pacing (LBBAP)?


This nonrandomized cohort study (I-CLAS [International Collaborative LBBAP Study]) enrolled patients with left ventricular ejection fraction ≤35% who underwent BVP or LBBAP for cardiac resynchronization therapy (CRT).


The study enrolled 1,778 patients. There were 1,414 propensity score–matched patients. The occurrence of VT/VF was significantly lower with LBBAP compared with BVP (4.2% vs. 9.3%). Among 299 patients with CRT pacemakers, VT/VF occurred in 7.2% in the BVP group versus 0% in the LBBAP group (p < 0.001). In 1,194 patients with no history of VT/VF or antiarrhythmic therapy, the occurrence of VT/VF was significantly lower with LBBAP than with BVP (3.2% vs. 7.3%). Among patients with no history of AF, the occurrence of new-onset AF >30 seconds was significantly lower with LBBAP than with BVP (2.8% vs. 6.6%). The incidence of AF lasting >24 hours was also significantly lower with LBBAP than with BVP (0.7% vs. 2.9%).


The authors conclude that LBBAP is associated with a lower incidence of sustained VT/VF and new-onset AF compared with BVP.


In patients with heart failure (HF), reduced ejection fraction, and wide QRS, BVP was long ago shown to improve HF outcomes and to reduce the incidence of ventricular arrhythmia over implantable-cardioverter defibrillator alone. Conduction system pacing, especially LBBAP, has represented a major leap forward in reducing ventricular dyssynchrony during pacing. A number of smaller cohort studies point to multifarious benefits of LBBAP. Prior publication from this large multicenter observational cohort showed that LBBAP was associated with improved clinical HF outcomes over BVP among patients undergoing CRT implantation. The present study provides additional data on the incidence of arrhythmia, suggesting that physiological pacing is less arrhythmogenic. Well-designed prospective randomized studies are needed to confirm these findings.

Clinical Topics: Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, Implantable Devices

Keywords: Cardiac Pacing, Artificial, Cardiac Resynchronization Therapy

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