| Objective To explore the feasibility and accuracy of real-time three-dimensional echocardiography (RT-3DE) for quantitative evaluation of left ventricular function and left ventricular systolic dyssynchrony in patients with heart failure .Methods Thirty-six heart failure (HF) patients and thirty-three healthy volunteers underwent M-mode echocardiography (ME), two-dimensional echocardiography (2DE), tissue Doppler imaging (TDI) and RT-3DE. The ejection fraction of left ventricular was obtained by ME , 2DE and RT-3DE. The mitral annular displacement (MAD) and septal-to-posterior wall motion delay (SPWMD) were measured using ME. MAD was regarded as a criterion of evaluating left ventricular systolic function. The electromechanical delay (EMD) was measured using TDI. The standard deviation of electromechanical delay (EMD-SD) was caculated by statistic software. SPWMD and EMD-SD were regarded as the indexes of systolic asynchrony. The global and 17-segmental time-volume curves were obtained by the on-line Qlab software (version 4.2). The time to minimal systolic volume in each segment (Tmsv) was taken to derive the following indexes of systolic asynchrony: Tmsv-16-SD, Tmsv-16-Dif, Tmsv-12-SD, Tmsv-12-Dif, Tmsv-6-SD and Tmsv-6-Dif , which meant the standard deviation or the maximal difference of Tmsv among the 16, 12 and 6 segments of the left ventricular respectively. The software also provided with each of the above asynchrony parameters as a percentage of the cardiac cycle. All the indexes of systolic asynchrony were regressed and compared by statistic software.Results①The left ventricular ejection fraction (LVEF) obtained by ME and those of obtained by 2DE and RT-3DE were significantly different in HF group (P<0.01). The LVEF obtained by 2DE and RT-3DE were no significantly different in HF group.②The LVEF determined by RT-3DE had a good correlation with MAD (r=0.910, P <0.001).There were close correlations between the LVEF determined by 2DE and ME and MAD (r=0.844 and r=0.662,all P <0.001,respectively) .③LVEDV and LVESV were markedly higher in HF patients than in controls(P< 0.01). LVEF was markedly lower in HF patients than in controls(P<0.01). LVEDV-2D, LVESV-2D and LVEDV-3D, LVESV-3D had significant difference in HF patients (P<0.01). But no significant difference was found between LVEDV-2D, LVESV-2D and LVEDV-3D, LVESV-3D in controls.④All the indexes of systolic asynchrony were significantly larger in HF group than those of the control group (all P<0.01).There were close negative relations between the LVEF derived by the biplane Simpson's on 2DE and each of the indexes of systolic asynchrony determined by RT-3DE, among which the correlation coefficient of the index of Tmsv-16-SD% was the highest(r=-0.786). The correlation coefficients between SPWMD, EMD-SD and LVEF were -0.616 and -0.723,respectively. Tmsv-16-SD% had a good correlation with EMD-SD (r=0.634,P <0.01).⑤Using a Tmsv-16-SD% of >3.1%(+2 SD of normal controls) to define significant systolic asynchrony, identified 30(83%)patients in HF group with significant systolic asynchrony. When a EMD-SD>23.1ms(+2 SD of normal controls) was used, it was present in 27(75%)patients in HF group with significant systolic asynchrony. Using a SPWMD≥130ms(+2 SD of normal controls) to define significant systolic asynchrony, identified 21(64%)patients in HF group with significant systolic asynchrony.⑥The Kappa value of RT-3DE and TDI was 0.750, indicated that the outcome of two methods was rather more consistent than that of RT-3DE and ME, because the Kappa value of RT-3DE and ME was 0.437.Conclusion①RT-3DE provides a simple, useful and efficient approach to assess the systolic asynchrony of all the left ventricular segments simultaneously.②RT-3DE is a novel noninvasive and reliable method to quantitatively evaluate left ventricular volume and its systolic function of HF patients.③RT-3DE may be a urefull alternative to TDI for the evaluation of LV asynchrony in HF patients.
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