Ventricular dyssynchrony and increased BNP levels in right ventricular apical pacing.

ABSTRACT

BACKGROUND: Long-term right ventricular apical pacing can cause ventricular dyssynchrony and, secondarily, neurohumoral alterations and increase in cardiac morbimortality. OBJECTIVE: To analyze ventricular dyssynchrony and its effects on BNP levels in patients with pacemakers and long-term right ventricular (RV) apex pacing. METHODS: Cross-sectional study of 85 patients with single or dual chamber pacemaker, NYHA functional class I or II and left ventricular ejection fraction (LVEF) ≥ 35%. The dyssynchrony assessment was carried out using several echocardiographic techniques, including Tissue Synchronization Imaging (TSI), with the analysis of the 12 segments. BNP was measured at the same time when the echocardiogram was performed, but the examiner was blinded to the results. RESULTS: Forty-six women and 39 men, aged 58 ± 12 years, with Chagas' disease (56%) and controlled hypertensive individuals (62%), were included in the study. LVEF was 52 ± 8% and the mean QRS duration was 139 ms (120-180 ms). BNP levels were altered in 36.5% of the sample (cutoff = 60 pg/ml). At the multivariate linear regression analysis, BNP was correlated with age (p = 0.024), LVEF (p < 0.0001) and left ventricular (LV) pre-ejection time (p = 0.009), which is an intraventricular dyssynchrony index. CONCLUSION: In clinically stable patients receiving conventional cardiac pacing, the intraventricular dyssynchrony was an independent predictor of BNP level increase after adjusted for age and LVEF.