[Mitral regurgitation due to abnormal reinsertion of chordae tendineae (looping) of the posterior mitral leaflet: clinical and echocardiographic features].

Two-dimensional (2D) echocardiographic and clinical characteristics of patients with mitral regurgitation (MR) due to abnormal reinsertion of chordae tendineae (looping) in the middle scallop of the posterior leaflet were described and compared with those of patients with chordal rupture of the posterior leaflet. Twenty-five patients with posterior mitral valve prolapse who underwent mitral valve replacement were studied. They were categorized in three groups; 14 patients with MR due to ruptured chordae tendineae (RCT) of the posterior leaflet (RCT group); three patients with looping of the chordae tendineae in the middle scallop of the posterior leaflet (looping group); and eight patients with both RCT and looping (looping + RCT group). It was difficult to distinguish the looping group from the other two groups by their 2D echocardiographic findings, which were characteristic of those of RCT. However, the following findings were more frequently encountered in the patients with looping than in those without: 1) aberrant or absent systolic coaptation with salient arc of the posterior leaflet, observed in six of the RCT group (43%), two in the looping group (67%) and seven in the looping + RCT group (88%); 2) with thickened edges of the posterior leaflet, shown in three of the RCT group (21%), two of the looping group (67%) and five of the looping + RCT group (63%) in the long-axis view, and also noticed in four of the RCT group (29%), two of the looping group (67%) and six of the looping + RCT group (75%) in the short-axis view. In the clinical history, the onset of a heart murmur, congestive heart failure and surgical treatment occurred at significantly younger ages in the looping group than in the RCT group. As for hemodynamic parameters, pulmonary hypertension was significantly milder in the looping group than in the RCT group. In conclusion, although 2D echocardiographic findings of patients with looping were similar to those of patients with RCT, it seemed possible to differentiate the looping group from the RCT group by the 2D finding of a prolapsed posterior mitral valve with a salient arc and a thickened edge. It was also suggested that the looping of chordae tendineae in the middle scallop of the posterior leaflet was congenital in origin.