Usefulness of real-time three-dimensional echocardiography to quantify global left ventricular function and mechanical dyssynchrony after heart transplantation.

OBJECTIVE

The purpose of this study was to examine left ventricular global function and left ventricular mechanical dyssynchrony (LVMD) after heart transplantation using three-dimensional echocardiography (RT-3DE) and to evaluate the value for RT-3DE in predicting cardiac allograft rejection (CAR).

METHODS AND RESULTS

A total of 95 consecutive patients undergoing orthotropic heart transplantation, of whom 20 had CAR and 75 had no CAR, were enrolled in this study. Forty healthy volunteers were included as the control group. All patients underwent RT-3DE examination. Time to minimum systolic volume (Tmsv) of each left ventricular segment was measured. The parameters of LVMD including the standard deviation (SD) of Tmsv of 16 segments (Tmsv 16-SD), 12 segments (Tmsv 12-SD), and 6 basal segments (Tmsv 6-SD) were automatically calculated.The parameters of LVMD were adjusted by cardiac cycle and presented in terms of percentage as Tmsv 16-SD%, Tmsv 12-SD%, and Tmsv 6-SD%.

RESULTS

The excursion average (Avg), excursion max (Max) and left ventricular ejection fraction (LVEF) were lower in patients with CAR than in those without CAR (all P < 0.05), while not different between patients without CAR and control subjects (all P > 0.05).The LVMD parameters, including Tmsv 16-SD, Tmsv 12-SD, Tmsv 6-SD, Tmsv 16-SD%, Tmsv 12-SD%, and Tmsv 6-SD%, were greater in patients with CAR than in those without CAR, while not different between patients without CAR and control subjects. All the RT-3DE parameters (LVEF and LVMD parameters) can predict CAR. However, Tmsv 16-SD (AUC 0.89 +/- 0.039, P < 0.001; sensitivity 85% and specificity 68%) and Tmsv 16-SD% (AUC 0.89 +/- 0.037, P < 0.001; sensitivity 95% and specificity 73%) offered the strongest power for detecting CAR.

CONCLUSION

CAR can induce LVMD. LVMD parameters obtained by 3D-RTE, especially Tmsv 16-SD and Tmsv 16-SD%, provides a good sensitivity and specificity for predicting CAR after heart transplantation.