Progressive Left Ventricular Outflow Tract Stenosis in a Noonan Syndrome Patient With Severe Hypertrophic Cardiomyopathy During Growth Hormone Treatment.

Short stature is a main problem in Noonan syndrome (NS). Recombinant human growth hormone (GH) has been used to safely improve the growth rate in NS patients with short stature. However, there is little information about GH therapy for NS associated with hypertrophic obstructive cardiomyopathy. We present the case of a seven-year-old NS patient with severe hypertrophic obstructive cardiomyopathy. The patient received GH therapy for six months, at which time progressive left ventricular outflow tract stenosis was apparent.