Evaluation of right ventricular systolic function after mitral valve repair: a two-dimensional Doppler, speckle-tracking, and three-dimensional echocardiographic study.

BACKGROUND: Conventional indices of right ventricular (RV) function are known to be reduced after cardiac surgery, as a consequence of geometric rather than functional alterations. New techniques, such as three-dimensional (3D) transthoracic and two-dimensional speckle-tracking echocardiography, may be useful in postsurgical RV assessment. The aim of this study was to compare indices of RV function obtained using different echocardiographic modalities, before and after surgery.

METHODS: Forty-two patients were screened the day before and 6 months after mitral valve repair. Twenty healthy patients were also enrolled as controls. Tricuspid annular plane systolic excursion and peak systolic velocity were calculated from Doppler tissue imaging. Longitudinal and radial strain values were obtained from speckle-tracking echocardiography. RV ejection fraction was calculated from 3D transthoracic echocardiographic RV volumes, and similarly, fractional area change was computed from RV areas.

RESULTS: Tricuspid annular plane systolic excursion (25 ± 4 vs 17 ± 3 mm), peak systolic velocity (17 ± 4 vs 12 ± 2 cm/sec), and fractional area change (43 ± 8% vs 39 ± 7%) significantly decreased after surgery (P < .01), while 3D RV ejection fraction was preserved (59 ± 7% vs 59 ± 6%). Speckle-tracking echocardiographic results were dependent on the considered direction, with preserved radial but decreased longitudinal strain values. All postoperative two-dimensional longitudinal indices were smaller than in controls. Preoperative parameters were not significantly correlated with RV functional changes.

CONCLUSIONS: Although 3D ejection fraction was preserved after surgery, in agreement with the lack of evidence of RV dysfunction, two-dimensional indices showed a functional loss in the longitudinal direction. Fractional area change, as a combination of radial and longitudinal properties, was slightly decreased. Speckle-tracking echocardiography could constitute a useful approach to relate local and space-dependent changes to the global RV function.