Live/Real Time Three-Dimensional Transesophageal Echocardiography

Relationship between geometric changes in mitral annular/leaflets and mitral regurgitation in patients with atrial fibrillation

The objective of the study was to determine the geometric changes in mitral annular and/or leaflets spatial conformation in patients with atrial fibrillation (AF) complicated with severe atrial mitral regurgitation (AMR) by using real-time 3-dimensional transesophageal echocardiography, aiming to explore whether this condition could be improved through self-modulation of mitral annulus and/or leaflets after the restoration of sinus rhythm.Fifty-five patients who were diagnosed with AMR and subject to 1-year follow-up were recruited in this clinical trial. All patients successfully received AF ablation. The intercommissural and anteroposterior diameter, annular height, mitral valve area (MVA), tenting height and volume, annular spherical index, fractional area change of MVA (MVA-FAC), and coaptation index (CP-I) were defined and measured by mitral-valve quantification software. Left ventricular size and function, maximum LA volume (LAV), and LA dimensions were equally recorded.During 1-year follow-up, AMR was significantly decreased in patients with sinus rhythm (P < 0.001). CP-I, MVA-FAC, and LAV index were independently associated with the reduction of AMR.AMR can be improved through the recovery of LAV after ablation, which probably affects the configuration of the annular space and the coaptation of the leaflets.

Three-dimensional echocardiography-based prediction of posterior leaflet resection

Clinical long-term outcomes have shown that partial leaflet resection followed by ring annuloplasty is a reliable and reproducible surgical repair technique for treatment of mitral valve (MV) leaflet prolapse. We report a 61-year-old male for three-dimensional transesophageal echocardiography (3DTEE)-based virtual posterior leaflet resection and ring annuloplasty. Severe mitral regurgitation was found and computational evaluation demonstrated substantial leaflet malcoaptation and high stress concentration. Following virtual resection and ring annuloplasty, posterior leaflet prolapse markedly decreased, sufficient leaflet coaptation was restored, and high stress concentration disappeared. Virtual MV repair strategies using 3DTEE have the potential to help optimize MV repair.

The impact of segmental volumetric changes on functional mitral regurgitation: a study using three-dimensional regional time-volume analysis combined with low-dose dobutamine

PURPOSE

Using transthoracic three-dimensional (3D) echo regional volume analysis combined with low-dose dobutamine to investigate the effects on regional volume, mitral configuration and functional mitral regurgitation (FMR).

METHODS

Fifty-six patients with ischemic cardiomyopathy (ICM) were included in this study. The effective regurgitant orifice area (EROA) of FMR secondary to ICM with depressed left ventricular ejection fraction was compared with mitral tenting area and coaptation height (CH) before and after low-dose dobutamine (10 μg/kg per min). Using 3-DQ software we measured and calculated regional stroke-volumes (rSV), the ratio of the rSV to the whole left ventricular stroke volume (rgSVratio) in all 17 segments and the average rgSVratio of 4 anterior-PM attached segments (rgSVratio-aver anter-PM), 4 posterior-PM attached segments (rgSVratio-aver post-PM), 8 PMs attached segments (rgSVratio-aver PMs) and all 17 segments before and after dobutamine.

RESULTS

Compared with the resting condition, the SVr and rgSVratio on the basal and mid segments of anterior, lateral, inferior, and posterior walls were increased after dobutamine infusion (P < 0.05). EROA at rest was associated with tenting area, CH and rgSVratio-aver of PMs and the reduction in EROA caused by dobutamine was associated with reductions in tenting area, CH and increases in rgSVratio-aver of PMs. Tenting area was associated with rgSVratio-aver of PMs and reduction caused by dobutamine was associated with increases in rgSVratio-aver of PMs.

CONCLUSIONS

The FMR decreasing during low-dose dobutamine is quantitatively associated with the regional LV volume change of attached PMs. Real time transthoracic three-dimensional echocardiography may provide a simple and noninvasive approach to assess regional LV time-volume characteristic during FMR.