2001 年 65 巻 2 号 p. 132-135
This report describes an adult patient with Noonan syndrome accompanied by biventricular hypertrophic cardiomyopathy causing isolated right ventricular outflow tract obstruction. Biventricular hypertrophic cardiomyopathy causing right- and/or left-side outflow tract obstruction, as well as valvular pulmonary stenosis, is relatively common in infants with Noonan syndrome. However, this condition without a dysplastic pulmonary valve, or indeed any polyvalvular dysplasia, is rare in adults with Noonan syndrome. Treatment with a β-adrenergic receptor blocking agent improved the patient's symptoms. Because neither the etiologic and prognostic relationship nor the genetic linkage between hypertrophic cardiomyopathy associated with Noonan syndrome and non-syndromic hypertrophic cardiomyopathy is clearly defined, clinicopathological findings and further follow-up may provide important evidence for the pathogenesis of hypertrophic cardiomyopathy. (Jpn Circ J 2001; 65: 132 - 135)