Heart
Cardiac involvement is a significant cause of mortality in patients with MPS disorders, including
MPS VI. Thickening and calcification of the aortic and mitral valves lead to valvular dysfunction.
Cardiac hypertrophy, pulmonary hypertension, and narrowing of coronary arteries also occur,
leading eventually to congestive heart failure. Patients 5 years of age and younger have
sometimes presented with cardiomyopathy or endocardial fibroelastosis. In addition, narrowing of
the abdominal aorta, the visceral arteries, and the renal arteries may promote systemic
hypertension.1-3
When 63 patients with various forms of MPS (age 21 months
to 25 years) were screened using echocardiography, cardiac
abnormalities were seen in 76% of the patients; the most
common findings were mitral valve thickening (66%), mitral
regurgitation or stenosis (44%), and aortic valve thickening
(27%). Twenty-three patients underwent 2 or more serial echo
screenings (separated by 1 to 8 years); in 83% of these
patients, significant worsening was seen in the second echo
screening relative to the first.4
- Neufeld EF, Muenzer J. The mucopolysaccharidoses. In: Scriver CR, Beaudet AL, Sly WS, Valle D,
eds. The Metabolic and Molecular Bases of Inherited Disease. Vol 3. 8th ed. New York, NY: McGraw-
Hill; 2001:3421-3452.
- Miller G, Partridge A. Mucopolysaccharidosis type VI presenting in infancy with endocardial
fibroelastosis and heart failure. Pediatr Cardiol. 1983;4:61-62.
- Hayflick S, Rowe S, Kavanaugh-McHugh A, et al. Acute infantile cardiomyopathy as a presenting
feature of mucopolysaccharidosis VI. J Pediatr. 1992;120:269-272.
- Dangel JH. Cardiovascular changes in children with mucopolysaccharide storage diseases and
related disorders—clinical and echocardiographic findings in 64 patients. Eur J Pediatr. 1998;157:534-
538.
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