Assessment of left ventricular function by analysis of volume-time curves of 16 segments with real-time three dimensional echocardiography: Left ventricular asynchrony as a clinical parameter for patients with heart failure

Background and Objectives : Recent technical developments with high-resolution real-time 3-dimensional echocardiography (RT3DE) have facilitated the acquisition of high quality images and the analysis of segmental volume-time curves (VTCs). The purposes of this study were to assess left ventricular (LV) asynchrony with using the VTCs of 16 segments by RT3DE and to compare this with tissue Doppler imaging (TDI) as a clinical parameter. Subjects and Methods : Twenty-three heart failure (HF) patients (LVEF: 25 ± 6%, age: 60 ± 13 years) and 16 normal controls underwent TDI and RT3DE at baseline and 1-year. The standard deviation (803) of the end systolic time to reach the minimal systolic volume for the 16 segments on VTCs was obtained by RT3DE. The standard deviation (SD₂) of the electromechanical coupling time for the 8 segments was measured using TDI. Results : SD₃ was markedly higher in the HF patients than that in the controls (7.7 ± 2.5 vs 1.5 ± 1.0%, respectively, p<0.01) and it increased as the LVEF decreased (r=-0.85, p<0.01). SD₂ was also significantly higher in the HF patients (27.0±8.6 vs 12.6±5.0 msec, respectively, p<0.01) and it had good negative correlation with the LVEF (r=-0.72, p<0.01). SD₃ was well correlated with SD₂ (r=0.66, p<0.01). At 1-year, the HF patients with an increased LVEF showed a decreased SD₃ (7/13). In contrast, the patients with a decreased LVEF had an increased SD₃ (3/13). Conclusion : The analysis of VTCs for the 16 LV segments with using RT3DE from a single acoustic window may be a useful clinical parameter for evaluating the LV function, including LV asynchrony, the LV volume and the LVEF.