Abstract 13951: Right Anterior Oblique in Addition to Left Anterior Oblique Projections Are Useful to Implant Right Ventricular Pacemaker Lead Into Mid-Septum and Achieve More Physiological Pacing

Abstract

Introduction: It has been reported that it is difficult to implant right ventricular (RV) leads to the true mid-septum using conventional fluoroscopic criteria. Thus, we investigated which is the best method to achieve the true RV mid-septum using 3 dimensions (3D) reconstruction of 64-slice multidetector computed tomography (64 MDCT). Methods and Results: We retrospectively analyzed 33 patients in whom we intended to place RV lead into the septum using conventional fluoroscopic criteria, 40 degree left anterior oblique (LAO40), and performed 64 MDCT later. 3D reconstruction of 64 MDCT revealed that the right ventricular lead was anchored on the true mid-septum in 10 patients (only 30%; MS group, n=10), anterior wall in 19 patients, and free wall in 4 patients (non-MS group, n=23). After implantation of the pacemaker, we evaluated the predictive value of MS group when we used electrocardiography criteria (q wave or negative QRS complex in lead I), 90 degree left lateral (LL90) view and 30 degree right anterior oblique (RAO30) view using 3D reconstruction of 64 MDCT in addition to LAO view. As shown in a table, the method using both LAO and RAO views was the best to achieve the true RV mid-septum among these methods. MS group had significantly shorter paced QRS duration and ΔQRS (paced QRS-own QRS) than non-MS group (139±21.9ms vs. 155.3±10.9ms, p=0.03 and 24.2±21.2ms vs. 55.5±9.1ms, p=0.0001). Conclusions: The true mid-septum RV pacing could achieve more physiological pacing. Not only confirming rightward orientation in LAO view but also aiming the middle of the cardiac silhouette in the RAO view may be a simple and accurate way to achieve the true RV mid-septum positioning.