OBJECTIVETo assess left ventricular (LV) regional diastolic function in patients with hypertrophic cardiomyopathy (HCM) using single-beat real-time three-dimensional echocardiography (RT-3DE).

METHODSSixty-nine patients with HCM (LV ejection fraction≥45%) and 50 normal control subjects underwent examinations by two-dimensional echocardiography (2DE) and RT-3DE. The parameters analyzed by RT-3DE included the end diastolic sphericity index (EDSI), diastolic dyssynchrony index (DDI), dispersion end diastole [DISPED, including late (DDI-late) and early (DDI-early) diastole, dispersion end diastole (DISPED-late), and dispersion early diastole (DISPED-early)]. The patients were divided into 3 groups with impaired relaxation (n=23), pseudonormal filling (n=37), and restrictive filling (n=9).

RESULTSDDI and DISPED increased with the severity of diastolic dysfunction. In end diastole, DDI-late and DISPED-late were abnormal in cases with severe diastolic dysfunction (7.95∓2.75 and 26.76∓17.19, respectively, P<0.0001) but normal in cases with mild diastolic dysfunction. In early diastole, DDI-early and DISPED-early both increased in cases of mild (8.57∓2.24 and 25.44∓6.31, respectively, P<0.0001) and moderate (9.56∓4.66 and 35.42∓14.19, respectively, P<0.0001) diastolic dysfunction.

CONCLUSIONIn patients with HCM, dyssynchrony in early diastole is more obvious than that in late diastole and shows also a stronger correlation with diastolic dysfunction. This preclinical lesion can be detected by single-beat RT-3DE.