An observational study of the effect of coronary artery disease severity on acute pacing threshold and lead impedance in patients with permanent pacemaker

Objective: This study investigated the effect of coronary artery disease (CAD) severity, distribution and left ventricular ejection fraction (LVEF) on acute ventricular pacing threshold and lead impedance at the time of pacemaker implantation. Methods: One hundred and thirty-two patients who received a ventricular pacemaker or internal cardioverter-defibrilator (ICD) lead in our institution between 2007-2010 were included in this observational study. Patients were divided into ICD and anti-bradycardic pacemaker (PM) groups. Groups were compared for ventricular stimulation threshold, lead impedance and LVEF. Later, groups were sub-grouped according to the severity and distribution of CAD and subgroups were compared in both groups for ventricular stimulation threshold, lead impedance. Quantitative data of groups were compared by means of independent samples t-test. Results: Ventricular pacing thresholds were found significantly higher ICD group compared with PM group (p 0.05). Impedance and LVEF values were significantly lower in ICD group (p 0.05). Impedance and ventricular pacing thresholds were comparable in subgroups of ICD and PM groups. Our study does not confirm any relationship between pacing parameters and severity-distribution of CAD and LVEF. Conclusion: Patients with ventricular ICD lead had higher pacing thresholds but lower pacing impedance values comparing with PM group. This study did not find any significant relationship between pacing parameters at implantation and LVEF, severity and distribution of CAD.