Isolated cleft of the mitral valve: clinical spectrum and course.

We have reviewed the clinical presentations, courses, and outcomes of 90 patients seen at Texas Children's Hospital from 1983 through 2008 who had an isolated cleft of the mitral valve without some form of endocardial cushion defect. Additional congenital cardiac defects were present in 61 of the 90 patients, 35 of whom had a congenital syndrome. Seven patients had isolated cleft of the mitral valve without other intracardiac defects, and in these 7 there was a progressive increase in the degree of mitral regurgitation during a median time of 26.5 months from diagnosis to surgery. The patients ranged from a gestational age of approximately 32 weeks to 21.9 years of age. No death was observed among the 39 surgical patients, including 32 who had additional cardiac defects. There was a significant reduction in the degree of mitral regurgitation in all patients who underwent surgery. Among the 51 patients who did not have surgery, the degree of regurgitation did not change significantly over the course of 1 to 27 years' observation. Isolated cleft of the mitral valve is an uncommon (but not rare) congenital malformation of the mitral valve that can cause all degrees of mitral regurgitation but can be managed medically or surgically.