Cardiac resynchronization therapy with left bundle branch area pacing reverts electromechanical window negativity to a similar extent as biventricular pacing
F Klein, M Daliry, K C Smits, E Bressi, P M Deissler, J Van Koll, A M W Van Stipdonk, R M A Ter Bekke, D Grieco, J G L M Luermans, F W Prinzen, R Meiburg, L M Rademakers, K Vernooy, U C NguyenAbstract
Background
Cardiac resynchronization therapy (CRT) through left bundle branch area pacing (LBBAP) has been associated with reduced arrhythmogenic risk compared to biventricular pacing (BiVP). Electromechanical window (EMW) is a marker of electromechanical instability, and a negative EMW is associated with ventricular arrhythmias. We hypothesized that LBBA-CRT increases EMW at least as much as BiVP-CRT does.
Methods
129 CRT-recipients (LBBAP: n=63; BiVP: n=66) were included. EMW and echocardiographic reverse remodeling were evaluated before and 6–12 months after CRT implantation in the entire cohort and in a subgroup of patients with a negative EMW at baseline. EMW is calculated by subtracting the QT interval from the time interval of QRS onset to the aortic valve closure artifact (QAoC) using CW-Doppler echocardiography.
Results
EMW measurements were feasible in 67% of patients (n=86). No significant difference in ΔEMW was observed between LBBAP and BiVP. In patients with a negative EMW at baseline, both CRT strategies led to significant EMW increase (LBBAP: n=21, ΔEMW +13 ms (IQR -1 to 70), p=0.003; BiVP: n=36, ΔEMW +26 ms (IQR -2 to 54), p=0.006), there was no significant difference between CRT-groups (p=0.779). Left ventricular ejection fraction improved by 10%±11% and end-diastolic volume decreased by 37±51 ml (< 0.001), with no significant differences between LBBAP and BiVP. In multivariate analysis, a negative EMW at baseline, but not echocardiographic reverse remodeling, was the only independent predictor of EMW increase.
Conclusion
In CRT patients with a negative EMW at baseline, LBBAP and BiVP revert EMW to a similar degree.EMW calculation methodBoxplot EMW values pre- and post-CRT