Left bundle branch pacing lead for sensing ventricular arrhythmias in implantable cardioverter-defibrillator: A pilot study (LBBP-ICD study)

BACKGROUND Left bundle branch pacing (LBBP) has been suggested as an alternative modality for biventricular pacing in cardiac resynchronization therapy (CRT) -eligible patients. As it provides stable R -wave sensing, LBBP has been recently used to provide sensing of ventricular arrhythmia in patients receiving implantable cardioverter-de fi brillator (ICD) with CRT. OBJECTIVE The aim of this study was to analyze the long-term safety and ef fi cacy of the LBBP lead for appropriate detection of ventricular arrhythmia and delivery of antitachycardia pacing (ATP) in patients requiring de fi brillator therapy with CRT. METHODS CRT -eligible patients who underwent successful LBBP-optimized ICD and LBBP-optimized CRT with de fi brillator were enrolled. The LBBP lead was connected to the right ventricular-P/S port after capping the IS -1 connector plug of the DF-1 -ICD lead. LBBP-optimized ICD or LBBP-optimized CRT with de fi brillator was decided on the basis of correction of conduction system disease. Documented arrhythmic episodes and therapy delivered were analyzed. RESULTS Thirty patients were enrolled. The mean age was 59.7 +/- 10.5 years. LBBP resulted in an increase in left ventricular ejection fraction from 29.9% +/- 4.6% to 43.9% +/- 11.2% ( P < .0001). During a mean follow-up of 22.9 +/- 12.5 months, 254 ventricular arrhythmic events were documented. Appropriate events (n = 225 [89%]) included nonsustained ventricular tachycardia (VT) (n = 212 episodes [94%]), VT (n = 8 [3.5%]), and ventricular fi brillation (n = 5 [2.5%]). ATP ef fi cacy in terminating VT was 75%. Eleven percent of episodes (n = 29) were inappropriately detected because of T -wave oversensing. Inappropriate therapy (ATP) was delivered for 14 episodes (5.5%). Three patients (10%) had worsening of tricuspid regurgitation. CONCLUSION Sensing from the LBBP lead for arrhythmia detection is safe as w 90% of the episodes were detected appropriately. Future studies with a dedicated LBBP-de fi brillator lead along with algorithms to avoid oversensing can help in combining de fi brillation with conduction system pacing.