PO-03-012 STEPWISE APPLICATION OF ECG AND ELECTROGRAM BASED CRITERIA TO ENSURE ELECTRICAL RESYNCHRONIZATION WITH LEFT BUNDLE BRANCH PACING

Abstract

Left bundle branch pacing (LBBP) has emerged as an alternative to biventricular pacing. However, a systematic stepwise approach to ensure electrical resynchronization is lacking. To define a stepwise application of LBBP criteria that will simplify implantation and guarantee electrical resynchronization. A cohort of 24 patients from the LEVEL-AT trial (NCT04054895) who received LBBP and had electrocardiographic imaging (ECGI) (CardioinsightTM Medtronic, USA) at 45 days post-implant were included. The usefulness of ECG and electrogram based criteria to predict accurate electrical resynchronization with LBBP were analyzed. A two-step approach was developed. The gold standard used to confirm resynchronization was the change in ventricular activation pattern and shortening in left ventricular activation time, assessed by ECGI. Twenty-two (91.6%) patients showed electrical resynchronization on ECGI. All patients fulfilled pre-screwing requisites: lead in septal position in left-oblique projection and W paced morphology in V1. In the first step, presence of either right bundle branch conduction delay pattern (qR or rSR in V1) or left bundle branch capture Plus (QRS ≤120ms) resulted in 95% sensitivity and 100% specificity to predict LBBP resynchronization, with an accuracy of 95.8%. In the second step, the presence of selective capture (100% specificity, only 41% sensitivity) or a spike-R<80ms (100% specificity, sensitivity 46%) ensured 100% accuracy to predict resynchronization by LBBP. Stepwise application of ECG and electrogram criteria ensured accurate assessment of electrical resynchronization with left bundle branch pacing.