Abstract
Right ventricular apical pacing (RAP) has been reported to have the potential to lead to left ventricular (LV) dyssynchrony and impaired LV function. The plasma level of B-type natriuretic peptide (BNP) is increased in the state of abnormal ventricular wall stretch. Therefore, the aim of the present study was to examine the effect of LV dyssynchrony on BNP levels in patients with chronic RAP.
Thirty-four patients (17 women, age 69 ± 11 years) with preserved LV systolic function on permanent RAP (duration, 7.0 ± 4.7 years) underwent conventional echo-Doppler assessment and tissue Doppler imaging. Twenty-two normal subjects (8 women, age 66 ± 9 years) served as controls. The standard deviation (SD) and dispersion of the time-to-peak systolic velocity (TPV) among the 6 basal LV segments were used as the indexes of LV dyssynchrony.
Compared with control subjects, RAP patients had prolonged TPVs and heterogeneous LV contraction with greater values of TPV-SD (18 ± 8 ms versus 39 ± 15 ms, P < 0.001) and TPV-dispersion (42 ± 20 ms versus 93 ± 31 ms, P < 0.001). There were significant correlations between BNP levels and the indexes of LV dyssynchrony (r = 0.41, P = 0.017 for TPV-SD; r = 0.46, P = 0.006 for TPV-dispersion).
RAP is associated with LV dyssynchrony, which may accelerate BNP secretion.
