Left ventricular function after permanent pacemaker in pacemaker clinic follow-up

Chronic right ventricular pacing has deleterious effects to left ventricular function which may be asymptomatic. Prevalence of LV dysfunction (LVEF < 50%) in RV pacing in Thai patients is not known.

Patients in the Central Chest Institute of Thailand (CCIT) pacemaker clinic were retrospectively reviewed for their demographic and pacemaker data together with echocardiographic data for LV function. Analysis was done for those who were implanted for more than one year period.

Among the studied 118patients, male = 51 and female = 67, mean follow-up time 6.43 +/- 5.66 years, LV systolic dysfunction was identified in 21 (17.80%). Compared to those with no LV dysfunction, echocardiographic parameters showed larger LVsize (EDD 49.86 +/- 8.95 vs. 43.81 +/- 5.56 mm) and less thickness of the LV wall (11.05 +/- 1.60 vs. 12.49 +/- 2.79 mm). Studied clinical and pace parameters for correlation were hypertension (p = 0.048), coronary artery disease (p = 0.008), percent of ventricular pacing (p = 0.06), duration after implantation (p = 0.23), mode of pacing (p = 0.275), indication of implantation (p = 0.32, site of pacing lead (p = 0.279), moderate to severe MR (p = 0.003) and moderate to severe TR (p = 0.04).

LV dysfunction after pacemaker implantation was not infrequent. Parameters correlated to it were previous LV dysfunction, hypertension, coronary artery disease and increased amount of ventricular pacing. Mode of pacing and site of pacing lead were not correlated.