His bundle pacing in patients pacemaker indication and with mildly reduced ejection fraction

Abstract Background Right ventricular pacing (RVP) can be harmful and in a number of patients leads to deterioration of left ventricle function. The deleterious effect of RVP is particularly visible in patients with reduced ejection fraction. His bundle pacing (HBP) allows ventricular stimulation without electrical and mechanical dyssynchrony and should not be associated with deterioration of left ventricle function. In some patients HBP restores electrical and mechanical synchrony. Objective The aim of the study is to evaluate effect of HBP on left ventricle function in patient with reduced left ventricle ejection fraction (LVEF. Methods Twenty-one patients with indication for permanent pacing and with (LVEF) between 35 and 50% were included into the study. Age 71,9±10,44. Men 76,2%. 13 (61,9%) patients with permanent atrial fibrillation. In 33,3% of patients there were intraventricular conduction delay (IVCD), 3 (14,3%) with LBBB, 3 (14,3%) with RBBB and 1 (4,8%) with nonspecific IVCD. 6 patients were upgraded from previously implanted pacemaker. Mean QRS duration 133,6±37,85. Baseline ejection fraction (EF) 42,6±3,21%. Clinical and echocardiographic evaluation were performed at baseline and after 6–12 months of follow up. Results QRS duration narrowed from 133,6±37,85ms to 114,3±16,90ms (p=0,033) with HBP. HBP was associated with reduction of end systolic left ventricular volume (LVES) from 91,5±31,10ml to 75,9±38,56ml (p=0,0058). EF improved from 42,6±3,21% to 48,3±7,39% (p=0,0006). Improvement in EF in patients without myocardial infarction (MI) was better (42,6±3,23% to 49,5±8,04%, p=0,0053) than in patients with MI (42,6±3,37% to 47,0±6,79%, p=0,062). Increase in EF was also better in patients with atrial fibrillation (42,7±3,19% to 49,9±8,20%, p=0,0017) than int patients with sinus rhythm (42,4±3,46% to 45,6±5,28%, p=0,17). Functional capacity assessed by NYHA class improved significantly from 2,4±0,59 to 1,7±0,58. Ejection Fraction Conclusion His bundle pacing is associated with th significant clinical and echocardiographic improvement in patients with mildly reduced left ventricular ejection fraction and indication for permanent pacing. After 6–12 moths of HBP pacing the improvement in EF is greater in patients with atrial fibrillation and without myocardial infarction.