Conventional ventricular stimulation effects on patients with normal ventricular function

Abstract

Background: The stimulation of the right ventricle (RV) may be deleterious in patients with ventricular dysfunction; however there is little evidence about the impact of this stimulation in patients with normal ventricular function.

Objectives: To assess the clinical and laboratory evolution of patients with normal ventricular function submitted to implant of artificial cardiac pacemaker (PM).

Methods: 16 patients enrolled according to the following inclusion criteria: normal ventricular function defined by echocardiogram and presence of upper ventricular stimulation > 90% (generator telemetry assessment) submitted to a PM implant were prospectively studied. The following parameters were assessed: Functional Class (FC), walk test, BNP levels, echocardiography evaluation (conventional and intraventricular dyssynchrony) and quality of life test (SF36). The patients were assessed after 10 (t1), 120 (t2) and 240 days (t3). Data was compared throughout time according to ANOVA. Multiple comparisons of means were performed through Tukey's test.

Results: Among the assessed data, the following did not present significant statistic variation (p> 0.05): functional class, BNP levels, conventional echocardiographic parameters, intraventricular dyssynchrony (tissue Doppler). The walk test (between t2 and t3) and the time between septal contraction and LV posterior wall showed worsening (p<0.05), although they did not meet the dyssynchrony criteria. The quality of life assessment (SF36) showed improvement in the functional capacity, social aspects, and general status sub-items.

Conclusion: After 8 months, patients with normal ventricular function did not show clinical (FC and SF36) or laboratory alterations (conventional echocardiography, dyssynchrony parameters and BNP levels); however, there was a worsening in the walk test.