Feasibility and Safety of Permanent Left Bundle Branch Pacing in Patients With Conduction Disorders Following Prosthetic Cardiac Valves

Figure 1. AV nodal block in patients with RBBB/LBBB. (A) Patient no. 8 with RBBB developed AV nodal block. (B) AV nodal block was found in patient no. 13 with LBBB. (C) Patient no. 17 with RBBB also developed AV nodal block with an His-ventricular (HV) interval of 60 ms. AV, atrioventricular; RBBB, right bundle branch block; LBBB, left bundle branch block.

Figure 2. Successful LBBP in a patient with AVR with MVR plus TVR (patient no. 16). (A) LBB potential was recorded with the intrinsic LVAT being 66 ms. (B) Pacing at 3 V demonstrated nonselective LBBP with the stim-LVAT of 66 ms. (C) Selective LBBP was achieved under the low output at 0.5 V with the identical stim-LVAT of 66 ms. (D,E) Fluoroscopic images of LBBP in RAO view (D) and LAO view (E) revealed that the LBBP lead tip was distal and septal to the TVR and inferior to the AVR. AVR, aortic valve replacement; LAO, left anterior oblique; LBB, left bundle branch; LBBP, left bundle branch pacing; LVAT, left ventricular activation time; MVR, mitral valve replacement or repair; PV, prosthetic valve; RAO, right anterior oblique; TVR, tricuspid valve ring.

Figure 3. LBBP in a patient with TAVR (patient no. 19). (A) Example of a 71-year-old male who underwent TAVR and developed infranodal block. (B) Intrinsic rhythm with LBBB occurred after cessation of temporary right ventricular pacing and LBB potential (red arrow) was noted. (C) Pacing at 5 V resulted in correction of LBBB with nonselective LBBP with local myocardial fusion and stim-LVAT of 76 ms. Selective LBBP with discrete local ventricular myocardial electrogram was shown during pacing at 1 V with the same stim-LVAT of 76 ms. Note the subtle change in QRS morphology in lead V1 and intracardiac electrograms. (D,E) Fluoroscopic views of LBBP in a patient with TAVR were presented in RAO (D) and LAO (E) projections. HB, His bundle; LAO, left anterior oblique; LBB, left bundle branch; LBBB, left bundle branch block; LBBP, left bundle branch pacing; LVAT, left ventricular activation time; RAO, right anterior oblique; TAVR, transcatheter aortic valve replacement.