Changes in left ventricular twist after mitral valve repair.

Abstract

We performed echocardiographic tissue tracking to investigate whether mitral valve repair preserves left ventricular function. We studied 16 subjects without heart disease (11 male; mean age, 54.6 ± 15.1 years) and 18 patients in normal sinus rhythm undergoing solitary mitral valve repair (12 male; mean age, 53.6 ± 16.6 years). Transthoracic echocardiography was performed before and after surgery, and left ventricular apical and basal short-axis images were recorded. Left ventricular rotation angle was measured with off-line Vector Velocity Imaging (Siemens Medical Solutions USA Inc, Mountain View, Calif) at each slice level. Left ventricular ejection fraction was significantly higher in the control (68.4% ± 3.6%) and preoperative groups (70.9% ± 6.5%) than the postoperative group (59.4% ± 11.4%, P < .05). Left ventricular end-diastolic and end-systolic volumes were significantly greater in the preoperative group than the control group (130.0 ± 41.5 mL and 41.6 ± 16.6 mL vs 80.0 ± 16.7 mL and 26.6 ± 9.2 mL, respectively, P < .05). Left ventricular end-diastolic volume normalized postoperatively. Left ventricular twist was significantly greater in the preoperative group than the other groups (11.7° ± 4.1° versus 7.1° ± 3.8° and 8.2° ± 5.7°, P < .05). Left ventricular twist did not differ significantly between control and postoperative groups. New York Heart Association functional class improved from 1.6 ± 0.5 to 1.0 ± 0.0 after surgery (P < .05). Although preoperative left ventricular ejection fraction seemed normal, left ventricular twist was greater. Left ventricular twist normalized after surgery, suggesting that it preserves left ventricular function.