Anodal Capture for Multisite Pacing with a Quadripolar Left Ventricular Lead: A Feasibility Study.

BACKGROUND

Up to 40% of patients are CRT non-responders. Multisite pacing, using a unique quadripolar lead, also called multipoint/multipole pacing (MPP), is a potential alternative. We sought to determine the feasibility of intentional anodal capture using a single LV quadripolar lead, to reproduce MPP without the need of a specific algorithm (so-called "pseudo MPP").

METHODS

Consecutive patients implanted with a commercially available CRT device and a quadripolar LV lead in our department were prospectively included. The electric charge (Q, in Coulomb) of RV and LV pacing spikes were calculated for all available LV pacing configurations at the threshold. The best MPP was defined as the configuration with the lowest consumption (Q + Q + Q). The best "pseudo MPP" (Q + Q) and best BVp (Q + Q) were also calculated. A theoretical longevity was estimated for each configuration at the threshold without a safety margin.

RESULTS

A total of 235 configurations were tested in 15 consecutive patients. "Pseudo-MPP" was feasible in 80% of patients with 3.1 ± 2.6 vectors available per-patient and LV-LV (most distant electrodes) vectors were available in 47% of patients. Each MPP pacing spike electrical charge was comparable to "pseudo-MPP" (18,428 ± 6863 µC and 20,528 ± 5509 µC, respectively, = 0.15). Theoretical longevity was 6.2 years for MPP, 5.6 years for "pseudo-MPP" and 13.7 years for BVp.

CONCLUSIONS

"Pseudo MPP" using intentional anodal capture with a quadripolar left ventricular lead, mimicking conventional multisite pacing, is feasible in most of CRT patients, with comparable energy consumption. Further studies on their potential clinical impact are needed.