Quadripolar left ventricular (LV) leads allow for several pacing configurations in candidates for cardiac resynchronization therapy (CRT). Whether different pacing configurations may affect LV dyssynchrony and systolic function is not completely known. We aimed to evaluate the acute effects of different pacing vectors on LV electromechanical parameters in patients implanted with a quadripolar LV lead.
In this two-centre study, within 1 month of implantation 21 CRT patients (65 ± 8 years, 76 % men, 38 % ischemic) receiving a quadripolar LV lead (Quartet 1458Q, St Jude Medical) underwent LV capture threshold assessment, intracardiac electrogram optimization, and two-dimensional echocardiography during four pacing configurations: D1-P4, P4-RV coil, D1-RV coil, and P4-M2. LV dyssynchrony and contractile function were expressed by septal-to-lateral delay and global longitudinal strain (GLS).
LV capture threshold varied between the configurations (P