A Comparative Study of Clinical Profile and Outcomes of Patients with Ischemic and Non-Ischemic Complete Heart Block

BACKGROUND: Complete heart block (CHB) is a medical emergency and usually requires immediate intervention. Both cardiac ischemia or non-ischemic conditions can cause CHB. AIM: To compare baseline clinical characteristics associated with ischemic versus non-ischemic causes of CHB and their outcomes. MATERIALSAND METHODS: This was a single centre retrospective, observational study. Consecutive 250 patients with CHB from January-December 2016 were included. Patients were characterized into non-ischemic and ischemic groups based on cardiac marker elevation, electrocardiogram changes and/or cardiac catheterization findings. In all patients, demographics, pre-existing comorbidities, prior use of nodal blocking agents and ejection fraction (EF) were recorded. The primary outcome was all-cause mortality and secondary outcome was pacemaker implantation. STATISTICS ANALYSIS: Mean and standard deviation were calculated for all continuous variables. Percentages were calculated for all categorical variables. Unpaired studentst test was utilized to find out the difference between means and to calculate the significance level and p-value. RESULTS: Out of 250 patients, 137 had ischemic and 113 had non-ischemic CHB. The mean age was 60.54 years in ischemic group and 61.32 years in the non-ischemic group (p=0.58). Patients with ischemic CHB had a lower mean EF [44.2 %v/s 55.2 % (p