[Effect of resection of the anterior chordae on cardiac function after surgical correction of mitral valve insufficiency].

The preservation of cardiac function in surgical correction of mitral regurgitation implies partially or totally preserving the subvalvular apparatus. However, the conservation of the whole subvalvular apparatus during mitral valve replacement is technically difficult as the anatomical conditions are not always favourable. In order to determine the consequences of isolated resection of the anterior chordae, the authors studied global and segmental cardiac function by isotopic angiocardiography after mitral valve repair (n = 23) or replacement with conservation of the posterior chordae (n = 16) in 39 patients with isolated, non-ischaemic mitral regurgitation. The left ventricular ejection fraction decreased after valve replacement (64.1 +/- 8.5% to 57.4 +/- 10%, p = 0.01) but not after mitral valve repair (65 +/- 11.3% to 62.1 +/- 12.2%, p = NS). The ejection fractions of segments 4 and 5, corresponding to the zones of insertion of the anterior papillary muscle, decreased after valve replacement compared with repair (segment 4: -9 +/- 13.7 versus +2 +/- 11.3, p = 0.01) (segment 5: -15 +/- 13.2 versus 2 +/- 11.7, p = 0.003). The right ventricular ejection fraction improved after valve repair (40.9 +/- 9.1% to 46.4 +/- 10.1%, p = 0.03), whereas it remained unchanged after valve replacement (42.9 +/- 10.3% to 42.8 +/- 8.6%, p = NS). These results indicate a deleterious effect of isolated resection of the anterior chordae on cardiac function during mitral valve replacement with localised abnormalities of left ventricular function. This study supports the rationale of mitral valve repair or conservation of the anterior and posterior chordae during valve replacement for isolated mitral regurgitation.