Left ventricular systolic dyssynchrony in pediatric and adolescent patients with congestive heart failure.

BACKGROUND: Echocardiographic measures of left ventricular (LV) dyssynchrony in pediatric patients with heart failure (HF) have not been adequately evaluated. The aim of this study was to evaluate LV systolic dyssynchrony in pediatric patients with HF and normal children.

METHODS: Among a total of 68 patients, 22 had HF and 46 were normal. Doppler tissue imaging, M-mode echocardiography, and pulsed-wave Doppler echocardiography were performed. Intraventricular dyssynchrony using the maximal difference in time to peak myocardial systolic contraction (Ts), the standard deviation of Ts of 12 LV segments, septal-to-posterior wall motion delay, and interventricular dyssynchrony by measuring aortic and pulmonary pre-ejection delays were obtained.

RESULTS: The maximal difference in Ts (patients with HF, 91.27 ± 31.18 msec; controls, 45.93 ± 21.29 msec; P < .001), the standard deviation of Ts (patients with HF, 31.05 ± 10.68 msec; controls, 15.60 ± 7.70 msec; P < .001), septal-to-posterior wall motion delay (patients with HF, 117.14 ± 45.18 msec; controls, 48.69 ± 16.63 msec; P < .001) and interventricular dyssynchrony (patients with HF, 21.60 ± 16.27 msec; controls, 11.56 ± 9.38 msec; P = .03) were significantly prolonged in the HF group. Defining systolic dyssynchrony as a standard deviation of Ts > 31 msec (+2 standard deviations of normal controls) and a maximal difference in Ts > 89 msec in normal controls and 18 patients with HF due to dilated cardiomyopathy was included for analysis of systolic dyssynchrony; it was present in three (6.5%) and two (4.3%) controls and in nine (50%) and 10 (55%) patients with HF due to dilated cardiomyopathy, respectively. Low ejection fraction, elevated LV end-diastolic volume, and elevated LV end-systolic volume had significant correlations with systolic dyssynchrony. QRS duration was not significantly correlated with measures of dyssynchrony.

CONCLUSIONS: Systolic mechanical dyssynchrony is common in pediatric patients with HF. QRS duration is not a determinant of systolic dyssynchrony in pediatric patients. Echocardiographic measurements of systolic dyssynchrony are feasible in pediatric patients.