The principal aim is to analyze total left and right ventricular activation time in different CRT device programming algorithms (SyncAV) measured by non-invasive electrophysiology
patients after successful implantation of a CRT-D or CRT-P device in whom a cardiac magnetic resonance examination is possible and the device is equipped with the SyncAV® programming software
left bundle branch block before CRT implantation
PQ interval ≤ 250 ms before implantation
high-grade AV block
any contraindication concerning a safe CMR performance including claustrophobia
terminal heart failure (NYHA IV) or cardiac decompensation
life expectancy < 1 year