Implantation of standard defibrillator leads in the left bundle branch area: Experience from an international cohort

Abstract Background Left bundle branch area defibrillation (LBBAD) therapy is currently an off-label procedure. Nevertheless, it is a promising technique that reduces the number of leads in implantable cardioverter defibrillator (ICD) patients who require conduction system pacing. Objectives: to collect real-world data on LBBAD implantation and follow-up. Methods Retrospective periprocedural and follow-up data on electrocardiographic and electrical parameters, transthoracic echocardiography and clinical outcome were assembled from 12 international centres. Results In total, 163 patients (age 67±12 years, 137 males) were included. Implantation success rate was 88%. Defibrillation testing was performed in 85 patients and was effective in all cases. Paced unipolar QRS duration was 125 [119-135] ms with a V6R-wave peak-time of 76 [70-85] ms, a V6-V1 interpeak interval of 44 [45-54 ] ms. Capture threshold was 0.8 [0.5-1.1] V/0.4ms, sensing amplitude was 9.0 [6.2-12] mV and pacing and high-voltage impedances were 580 [493-650] Ohms and 66 [60-75] Ohms. Electrical parameters remained favourable over a follow-up of 8 [3-13] months. Left ventricular ejection fraction (LVEF) improved from 30 [26-35] % to 36 [31-46]% at last follow-up (P<0.001). A total of 13 appropriate and effective shocks were documented, affecting eight patients (4.9%). No ineffective shocks were reported. Two LBBAD leads were explanted more than one year after implantation without any complication. No deaths were related to LBBAD. Conclusion LBBAD with standard stylet-driven lead is safe and feasible, with stable electrical, ECG, and echocardiographic parameters at mid-term follow-up.