The utility of fully automated real-time three-dimensional echocardiography in the evaluation of left ventricular diastolic function.

BACKGROUND: A novel real-time three-dimensional echocardiography (RT3DE) system allows fully automated quantification of the left ventricular (LV) volume throughout a cardiac cycle. This study aimed to investigate whether an LV time-volume curve, obtained using fully automated RT3DE, is useful in the evaluation of LV diastolic function.

METHODS: First, 15 patients underwent simultaneous standard two-dimensional echocardiography (2DE), RT3DE, and cardiac catheterization to measure the time constant of the isovolumic-pressure decline (τ). From the LV time-volume curve obtained using RT3DE, peak early filling rate (PFR) during diastole was generated and indexed for LV end-systolic volume. Next 570 patients, who were scheduled for both 2DE and RT3DE examinations, were enrolled to investigate the association between PFR index and 2DE-evidenced diastolic dysfunction and clinical characteristics.

RESULTS: Of the 585 patients, RT3DE analysis was adequate in 542 patients (feasibility 93%). In the 15 patients, PFR index showed significant correlation with τ (r=-0.65, p=0.009). In the remaining 527 patients, PFR index was related to age (r=-0.24, p<0.001) and e' (r=0.41, p<0.001). PFR index decreased in proportion to the grade of 2DE-evidenced diastolic dysfunction. All patients with normal diastolic function had a PFR index greater than 2.0.

CONCLUSIONS: This study demonstrated that a novel, fully automated RT3DE-derived PFR index was the diagnostic tool of choice for the assessment of LV diastolic function.