The resynchronization effect in left bundle branch pacing can be evaluated non-invasively with implementation of lead V8
J Van Koll, V Ramalingam, P Tai, V Essebag, T A Hadjis, T A R Lankveld, A M W Van Stipdonk, J H J Rijks, K H M Opmeer, U C Nguyen, J Lumens, J G L Luermans, A Verma, K Vernooy, J JozaAbstract
Background
The evolution of cardiac resynchronization therapy (CRT) toward more physiologic pacing strategies has led to the growing adoption of left bundle branch area pacing (LBBAP). Nevertheless, in cases where complete resynchronization is not achieved, the implantation of an additional left ventricular (LV) lead remains necessary. A simple non-invasive method of determining the persistence of posterolateral LV wall delay would thus be of particular importance.
Purpose
To evaluate whether lead V8 can serve as a non-invasive marker of LV posterolateral delay during LBBAP.
Methods
Consecutive patients undergoing LOT-CRT implantation at two tertiary centres were included. Standard 12-lead ECGs were obtained with the V5 electrode repositioned to the V8 location at the inferior aspect of the left scapula (Figure 1A). Local activation time was measured as the steepest negative downslope of the QRS complex (negative derivative activation time, NDAT, figure 1B) and compared with the LV electrical delay (LVED) determined from the LV lead during LBBAP (Figure 1C, D). NDAT-V6 and R-Wave Peak Times (RWPT) in V6 and V8 were also evaluated. Correlation and agreement were assessed using linear regression and Bland-Altman analysis.
Results
Thirty consecutive patients undergoing LOT-CRT implantation were included with a total of 106 ECG recordings during intrinsic rhythm and LBBAP with corresponding LVED measurements. The NDAT in V8 demonstrated a strong correlation with the LVED interval during intrinsic conduction (r=0.95) as well as during all LBB pacing subtypes (combined r=0.922; RV septal pacing r=0.8; LV septal pacing r=0.92; nsLBBP r=0.91; and sLBBP, r=0.8) (Figure 2). The correlation of LVED during intrinsic conduction and all LBBAP pacing subtypes was significantly weaker for NDAT-V6 and the RWPT in V6 and V8 (r=0.681, 0.626 and 0.726, respectively).
Conclusion
The NDAT in lead V8 provides a reliable non-invasive surrogate for the LV posterolateral wall delay during LBBAP, outperforming NDAT-V6 and the RWPT in V6 and V8 and establishes the groundwork for future studies evaluating NDAT-V8 as a tool to guide adequate resynchronization during LBBAP.NDAT Across Pacing ConfigurationsCorrelation and bland-Altman analyses