Cardiac Resynchronization Therapy using Left-Bundle-Branch Area and Left
Ventricular Pacing
Abstract
Introduction: Cardiac resynchronization therapy via biventricular pacing
is an established therapy for patients with heart failure. However, high
nonresponder rates and inability to predict response remains a
challenge. Recently left bundle branch area pacing (LBBAP) has been
shown to be feasible and may also improve clinical outcomes. In this
article we describe sequential LBBAP followed by left ventricular (LV)
pacing (LOT-CRT) and assess the feasibility of LOT-CRT. Methods: The RV
implantation site was positioned and the LBBAP lead was implanted using
our methods. The QRS duration (QRSd) at baseline, during LBBAP,
biventricular pacing, and LOT-CRT was measured. Results: LOT-CRT was
successful in 5 patients (age 71.8 ± 5.1 years, men 3, ischemic 3). The
QRSd at baseline was 158.0 ± 13.0 ms and significantly narrowed to 117.0
± 6.7 ms during LOT-CRT (P < 0.01). During 3-month follow-up,
LV ejection fraction improved from 32.8 ± 5.2 % to 45.0 ± 5.1% (P
< 0.01), and New York Heart Association functional class
changed from 3.25 ± 0.5 to 2.5 ± 0.6 (P < 0.05). A decrease in
left ventricular end-diastolic dimension was observed, with widening
from (68.2 ± 12.3) mm at baseline to (62.2 ± 11.3) mm at pacing (P
< 0.05). The length of operation time was (152.0 ± 31.1) min.
Conclusions: The study demonstrates that LOT-CRT is clinically feasible
in patients with systolic HF and LBBB. LOT-CRT was associated with
significant narrowing of QRSd and improvement in LV function, especially
in patients with ischemic cardiomyopathy.