Left bundle branch area. A new site for physiological pacing: a pilot study

Chronic RV pacing may lead to pacing induced cardiomyopathy in some patients and results in a higher risk of development of LV systolic dysfunction, heart failure, mitral regurgitation and atrial fibrillation. His bundle pacing emerged as the most physiologic form of ventricular pacing. However, wide adoption of this technique in routine clinical practice is limited by higher capture thresholds at implant sometimes, lower R wave amplitudes, atrial over sensing and increased risk for late rise in pacing thresholds (resulting in the need for lead revisions). Some recent studies have focused on left bundle branch area pacing as a solution to these problems. In our study, we have compared left bundle branch area pacing (in 22 patients) with conventional right ventricular apical pacing (in 28 patients) who presented to us with conventional indications for pacemaker implantations in term of procedure and fluoroscopy time and short-term lead performance and left ventricular function. The results of our study showed that left bundle branch area pacing is associated with shortened QRS duration (22.36 ± 9.36 ms) and better LV function (higher left ventricular ejection fraction 64.00 ± 3.03 vs. 59.73 ± 6.73 with a p value of 0.013 and lower left ventricular diastolic internal diameter 4.58 ± 0.32 vs. 5.23 ± 0.40 cm with a p value of < 0.001) in comparison to right ventricular apical pacing. The total procedure time and fluoroscopy time was similar (63.15 ± 7.02 vs. 55.15 ± 6.16 min, p value 0.142 and 6.08 ± 1.42 vs. 5.06 ± 1.30 min, p value 0.332 respectively) in left bundle branch area pacing group. The results of this study indicate that left bundle branch area pacing may be an option for physiological pacing in patients requiring a high percentage of ventricular pacing.