3.1 Patient and pacing characteristics
A total of 1132 underwent PM implantation during the study period. Of
these, 134 patients with pre-implantation LVEF < 50.0% were
excluded. Another 249 (24.9 %) patients were lost to follow-up and were
excluded. Hence, a total of 749 patients were included in the final
analysis.
The mean age of the cohort was 59.2 ± 14.1 years and 31.6% were female.
The most common indication for pacing was degenerative high-grade AV
block seen in 74.37% of the study population. The other causes included
sick sinus syndrome, carotid sinus hypersensitivity and syncope of
unknown origin. About half of the patients had baseline bundle branch
block or intraventricular conduction defect (IVCD). Mean
pre-implantation LVEF was 57.3 ± 3.3 %. The majority of the patients
(71.2 %) received a dual-chamber pacemaker and most (69.6 %) had an RV
lead placed in a non-apical location. The median RV pacing burden was
81% (IQR 15-99%). Other patient, procedural, and pacing
characteristics are summarized in Table 1.