[Real-time Three-dimensional Dobutamine Stress Echocardiography for the Evaluation of Ischemic Mitral Regurgitation]

To evaluate mitral regurgitation (MR) and left ventricular myocardial function in the patients with ischemic mitral regurgitation (IMR) by real-time three-dimensional dobutamine stress echocardiography (RT3D-DSE).

Seventy two consecutive in-patients with myocardial infarction and MR were enrolled in the study during 2006-2012. Each patient underwent RT3D-DSE examination before treatment. Three-dimensional (3D) heart full-volume data and 3D MR were obtained at baseline and each stress state. Quantitative parameters including: left ventricular end-diastolic/systolic volume (LVEDV/LVESV), left ventricular ejection fraction (LVEF) , left ventricular diastolic /systolic mass (LVMd/s). The time to the point of minimal regional systolic volume (Tmsv) was measured from the time volume curves of 17 segments, the standard deviation (Tmsv-SD) and maximal difference (Tmsv-Dif) of Tmsv were calculated. Excursion max (Emax), excursion SD (Esd), vena contarcta area (VCA) also were measured.

94.4% patients reached dobutamine (Dob) at 30 µg/(kg · min), 69.4% patients completed Dob 40 µg/(kg · min), only 38.9% patients completed Dob at 50 µg/(kg · min). At different stress state, VCA decreased significantly, and the decrement was up to the largest at 30 µg/(kg · min). 2D-LVEF, 3D-LVEF increased gradually, but decreased at 50 µg/(kg · min). 2D-LVESV and LVMd decreased, but increased at 50 µg/(kg · min). Tmsv-16/12/6 SD%, Tmsv-16/12/6 Dif% decreased, but increased at 50 µg/(kg · min). Eave and Esd increased, but decreased at 40-50 µg/(kg · min). Compared each with the baseline, LV remodeling parameters and VCA were statistically significant.

IMR patients showed a biphasic response during RT3D-DSE. The decrease of VCA is associated with an improvement of LV remodeling and synchronization when Dob ≤ 40 µg/(kg · min).