Biventricular Surgical Approach in Noonan Syndrome With Hypertrophic Obstructive Cardiomyopathy

Noonan syndrome is commonly associated with cardiac abnormalities such as pulmonary valve stenosis, hypertrophic cardiomyopathy, and atrial septal defect.

A 19-year-old woman who was diagnosed with Noonan syndrome at birth had been receiving medical treatment for hypertrophic cardiomyopathy. The patient developed symptomatic hypertrophic obstructive cardiomyopathy, characterized by biventricular outflow tract obstruction. Surgical intervention was performed, including atrial septal defect closure and myectomy through left and right ventriculotomy approaches.

A right ventriculotomy was performed to resect the parietal band, septal myocardium, and anterior wall muscle. This was followed by a left ventriculotomy, enabling an extended septal myectomy from the resection margin near the aortic valve down toward the apex. This approach allowed for the removal of abnormal muscle bundles that were not visible through the aortic valve.

When myectomy for hypertrophic obstructive cardiomyopathy is challenging, surgical access via both left and right ventriculotomy should be strongly considered.