Non-invasive electrophysiological assessment of the optimal configuration of quadripolar lead vectors on ventricular activation times

Cardiac resynchronization therapy (CRT) is now generally delivered via quadripolar leads. Assessment of the effect of different vector programs from quadripolar leads on ventricular activation can be now done using non-invasive electrocardiographic mapping (ECM). In nineteen patients with quadripolar LV leads, activation maps were constructed. The total ventricular activation time (TVaT) and the time for the bulk of ventricular activation (VaT10–90) were calculated. CRT delivered via a quadripolar lead significantly reduced TVaT and VaT10–90 by a mean of 16 ms and 31 ms, respectively, compared to baseline. There was a marked reduction in ventricular activation between the most and least synchronous vectors: 28% difference in baseline TVaT and 37% difference in VaT10–90. Changes in the configuration of an LV quadripolar lead significantly affected ventricular activation timings in both ischaemic and non-ischaemic subjects. This suggests that programming of the optimal pacing vector may need to be individually tailored. •Electrical resynchronisation by VaT10–90 reflecting the bulk of myocardial activation•Significant shortening compared to baseline via quadripolar lead•Reduction between optimal and worst vectors in both ischemic and non-ischemic•Optimal resynchronisation achieved using non-conventional bipolar configurations