Permanent and Atrial-Synchronized Ventricular Stimulation for Clinically Stable Patients with Normal or Impaired Left Ventricular Systolic Function

Authors


Address for reprints: John A. Chiladakis, M.D., F.E.S.C., Asst. Professor of Cardiology, Tavropou 16, Patras 26442, Greece. Fax: +30-2610-430-646; e-mail: chil@otenet.gr

Abstract

Background: Ventricular desynchronization imposed by permanent dual-chamber ventricular pacing (VDD) may compromise ventricular function.

Methods: We investigated the impact of background VDD pacing on the right and left ventricular (LV) function on 129 clinically stable outpatients (mean age 69 ± 10) implanted chronically with a dual-chamber pacemaker or an automatic defibrillator by using echocardiographic techniques including tissue doppler imaging (TDI) and color M-mode (CMM) examinations, and B-type natriuretic peptide (BNP) measurements. Patients were divided into two groups of normal (n = 65) or impaired (n = 64) LV systolic function (ejection fraction 63 ± 6% and 38 ± 10%, respectively) according to clinical and echocardiographic criteria. Each patient group included two subgroups on the basis of the underlying permanent and atrial-synchronized heart rhythm: either intrinsic ventricular activation (IVA) or VDD pacing.

Results: The BNP levels (mean, 95% CI) of patients with impaired LV systolic function were approximately threefold higher than those of patients with normal LV systolic function [189 (145–245) pg/mL vs 65 (50–85) pg/mL, P < 0.0001], but did not differ between subgroups of patients with IVA vs VDD pacing. By two-way analysis of variance and analysis of covariance, and after adjustment for age and gender, significant VDD pacing effects were found in terms of lower E/A ratio (P < 0.05) and increased LV end-systolic volume (P < 0.05). VDD pacing did not significantly affect the BNP levels and the LV filling pressures, as determined by the E/Ea and E/Vp ratios.

Conclusions: Long-term VDD pacing may not be harmful in clinically stable patients with normal or moderately reduced LV systolic function.

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