The Left Bundle Cardiac Resynchronization Therapy Trial

"Standard BiV-CRT The CRT-P/CRT-D device and leads should be implanted according to the physician's manual provided with the devices. Only locally approved Medtronic CRT-P/CRT-D generators will be used during the study. The LV lead should be implanted at a lateral or posterolateral CS branch in a basal or mid ventricular position confirmed by ortogonal fluoroscopic views (RAO and LAO 40º). Acceptable LV pacing threshold should be \<3V@0,5ms and phrenic nerve stimulation (PNS) margin should be \>1V with respect to the pacing threshold.~LBBAP-CRT The CRT-P/CRT-D device and leads should be implanted according to the physician's standard practice. Only locally approved Medtronic CRT-P/CRT-D generators will be used during the study. During the implant procedure lead impedances, pacing and sensing parameters will be measured using a pacing system analyzer (PSA). For LBBAP, the Medtronic 3830 lead will be used. Acceptable LBBAP threshold should be \<2,5V@0,5ms"