Isolated cleft in the posterior mitral valve leaflet: a congenital form of mitral regurgitation.

Background: Isolated congenital cleft of the posterior leaflet of the mitral valve is a rare cause of mitral regurgitation (MR). This study describes the clinical, echocardiographic, and intraoperative findings as well as treatment options.

Methods: Adults with an isolated cleft of the posterior mitral valve leaflet diagnosed by transthoracic echocardiography were evaluated with respect to clinical, echocardiographic, preoperative and intraoperative findings, and different surgical strategies.

Results: The prevalence of isolated cleft of the posterior mitral valve leaflet in all patients examined was 0.11% (n = 22 out of 19 320 evaluated echocardiograms); male gender was predominant (73%). Dyspnea on exertion was present in almost all patients with at least moderate regurgitation. The predominant localization of the cleft was within segment P2 (59%), followed by a cleft between P1/P2 (18%). An isolated cleft in segment P3 or segment P1 occurred twice in each segment (n = 2; 9%) and between P2/P3 once (n = 1; 5%). Regurgitation was severe in 50% (n = 11), moderate in 9% (n = 2), mild in 27% (n = 6), and only trivial in 14% (n = 3) of the patients. Surgical treatment involved reconstruction with ring annuloplasty in 45% (n = 10) and replacement in 4.5% (n = 1). A total of 11 patients (50%) with mostly mild or trivial mitral regurgitation were treated medically only.

Conclusion: Two-dimensional high-resolution cross-sectional echocardiography allows the distinct diagnosis of a clefted posterior leaflet, whereas clinical presentation, electrocardiogram, chest x-ray, and angiography are failing to identify the correct etiology of MR in patients with isolated posterior leaflet cleft mitral valve (IPLCMV). Patients with moderate to severe MR were treated surgically with excellent outcome.