A Feasibility Study Implant of the WiSE® CRT System With an Intracardiac Pacemaker to Achieve Totally Leadless CRT

Inclusion Criteria: * Patient with a class I or IIa (1) or (2) indication for implantation of a CRT device according to current available guidelines 1,2,4 (with additional QRS criteria on Class IIa (1)): * Class I: NYHA II, III, IV, EF ≤ 35%, LBBB, QRS ≥ 150 ms * Class IIa (1): NYHA II, III, IV, EF ≤ 35%, LBBB, QRS ≥ 130 to \< 150 ms * Class IIa (2): NYHA II, III, IV, EF ≤ 35%, non-LBBB, QRS ≥ 150 ms * Patient or legally authorized representative can provide written authorization and/or consent per institution requirements * Male or Female, aged 22 years or above * Meets criteria for one of the two patient groups * Group A: De novo totally leadless CRT implant in whom the physician believes a totally leadless approach would be beneficial (e.g., wish to avoid lifelong transvenous lead implant, anatomical constraints, history of device infection). * Patients with symptomatic AF and an uncontrolled heart rate who are candidates for AV node ablation (irrespective of QRS duration and LVEF), and in whom the physician believes a leadless pacing approach would be beneficial. * Patients with high degree AV block who have an indication for permanent pacing (with a LVEF ≤ 50%), are expected to require ventricular pacing more than 40% of the time, and in whom the physician believes a leadless approach would be beneficial. * Group B: Upgrade chronic intracardiac pacemaker to CRT * Patients with existing intracardiac pacemakers with greater than 20% RV pacing, wh…