Aortic regurgitation first appearing 12 years after successful septal myectomy for hypertrophic obstructive cardiomyopathy.

Substantial aortic regurgitation developed in a patient with hypertrophic (obstructive) cardiomyopathy (HCM) who underwent septal myectomy. It was first noted 12 years after surgery. There was no evidence for surgical damage to the valve, subacute bacterial endocarditis, coexisting discrete subaortic stenosis or any other known etiology of aortic incompetence. This experience suggests that aortic regurgitation occasionally may be a late mode of deterioration in surgically treated patients with hypertrophic cardiomyopathy. Possible mechanisms for the development of aortic incompetence in such patients are discussed.