The V6-V1 interpeak interval: a novel criterion for the diagnosis of left bundle branch capture

Europace. 2022 Jan 4;24(1):40-47. doi: 10.1093/europace/euab164.

Abstract

Aims: We hypothesized that during left bundle branch (LBB) area pacing, the various possible combinations of direct capture/non-capture of the septal myocardium and the LBB result in distinct patterns of right and left ventricular activation. This could translate into different combinations of R-wave peak time (RWPT) in V1 and V6. Consequently, the V6-V1 interpeak interval could differentiate the three types of LBB area capture: non-selective (ns-)LBB, selective (s-)LBB, and left ventricular septal (LVS).

Methods and results: Patients with unquestionable evidence of LBB capture were included. The V6-V1 interpeak interval, V6RWPT, and V1RWPT were compared between different types of LBB area capture. A total of 468 patients from two centres were screened, with 124 patients (239 electrocardiograms) included in the analysis. Loss of LVS capture resulted in an increase in V1RWPT by ≥15 ms but did not impact V6RWPT. Loss of LBB capture resulted in an increase in V6RWPT by ≥15 ms but only minimally influenced V1RWPT. Consequently, the V6-V1 interval was longest during s-LBB capture (62.3 ± 21.4 ms), intermediate during ns-LBB capture (41.3 ± 14.0 ms), and shortest during LVS capture (26.5 ± 8.6 ms). The optimal value of the V6-V1 interval value for the differentiation between ns-LBB and LVS capture was 33 ms (area under the receiver operating characteristic curve of 84.7%). A specificity of 100% for the diagnosis of LBB capture was obtained with a cut-off value of >44 ms.

Conclusion: The V6-V1 interpeak interval is a promising novel criterion for the diagnosis of LBB area capture.

Keywords: Conduction system pacing; Electrocardiogram; Left bundle branch capture; Left bundle branch pacing; Left ventricular septal capture.

MeSH terms

  • Bundle of His*
  • Cardiac Pacing, Artificial / methods
  • Electrocardiography / methods
  • Heart Conduction System
  • Humans
  • Ventricular Septum*