Cardiovascular abnormalities in Noonan syndrome: the clinical findings and treatments.

The clinical findings and treatment of cardiovascular abnormalities in 33 patients with Noonan syndrome are reviewed. Major cardiovascular abnormalities were pulmonary valvular stenosis in 17 patients (51.1%), hypertrophic cardiomyopathy (HCM) in 11 (33.3%), and atrial septal defect in 9 (27.3%). Dysplastic pulmonary valve was seen in 6 (35.3%). Balloon pulmonary valvuloplasty was performed for 4 patients with dysplastic pulmonary valves. Two patients were successfully treated. Surgical treatment was performed in 13 patients, 11 alive and 2 died. Two patients with HCM and arrhythmia died suddenly. In conclusion, balloon pulmonary valvuloplasty should be the initial palliation for dysplastic pulmonary valve in Noonan syndrome, and HCM is the risk factor for sudden death in Noonan syndrome.