Cardiac manifestations of the mucopolysaccharidoses.

The cardiovascular manifestations of the mucopolysaccharidoses (MPS) have not been well characterized. We studied nine children with various forms of MPS, using noninvasive cardiac diagnostic techniques. The echocardiograms of two brothers with Type I H/S MPS showed slow mitral valve early diastolic closure velocities (MVEDC) (18, 29 mm/sec) consistent with mitral stenosis. Each had a soft opening snap, low frequency presystolic murmurs and X-ray evidence of calcific mitral stenosis. Three patients with Type II A MPS had echocardiographic evidence of impaired left ventricular function, suggesting the presence of myocardial damage. One of these had an abnormal electrocardiogram; non had murmurs. No cardiac abnormalities were discovered in two patients with Type III A and IV MPS. One patient with Type VI A MPS had presystolic, holostolic and early diastolic murmurs. A soft opening snap was recorded. The echocardiogram showed a slow MVEDC (18 mm/sec) and a slightly enlarged left atrial dimension (2.2 cm/m2). In summary, noninvasive studies are useful in evaluating patients with MPS. Type I H/S and Type VI A patients may show evidence of valvular deformity, the former associated with mitral valvular calcification and the latter with both aortic and mitral valve involvement. Type II A patients have muscle function abnormalities and Type III A and IV are shown by noninvasive methods to be free of cardiovascular abnormalities.