Diastolic Dyssynchrony Differences in Patients with Single Right Ventricles vs. Control Patients

Diastolic dyssynchrony is increasingly being recognized as another marker for possible adverse cardiac events. Minimal data exist in hypoplastic left heart syndrome (HLHS) patients. The goal of this study was to determine if there were differences in diastolic dyssynchrony in patients with HLHS vs. control patients.

Tissue Doppler imaging (TDI) and strain rate (SR) analysis of the right ventricle in HLHS and control patients were performed. Time interval from onset of QRS complex on electrocardiography to peak TDI e' wave was obtained. Differences in intervals were calculated: QRSe'(RV) - QRSe'(IVS) and QRSe'(RV) - QRSe'LV). Time interval from onset of QRS to peak strain rate early diastolic wave (SRe) was obtained for the six-segment model RV. Standard deviation of the six SRe time intervals was calculated. t-tests were performed to determine if differences were present between groups. Sixty patients were studied (35 HLHS, 25 control). There were no significant differences between HLHS and control patients in age (6.5 ± 3.2 years vs. 6.1 ± 2.6 years) or heart rate (91 ± 22 bpm vs. 91 ± 13 bpm), respectively. There were no significant differences between HLHS and control patients in QRSe'(RV) - QRSe'(IVS) (19.9 ± 15.4 ms vs. 23.3 ± 13.6 ms) and QRSe'(RV) - QRSe'(LV) (20.7 ± 13.8 vs. 22.8 ± 14.6 ms), respectively. There was a significant difference in SRe standard deviation between the HLHS and control patients (25.3 ± 12.4 ms vs. 15.5 ± 6.9 ms, P = .0007), respectively.

Patients with HLHS had increased diastolic dyssynchrony compared with control patients as measured via deformation analysis. Future studies are needed to determine the significance of these findings.