Surgical treatment of hypertrophic obstructive cardiomyopathy with special reference to complications and to atypical hypertrophic obstructive cardiomyopathy.

The Düsseldorf surgical series of patients with hypertrophic obstructive cardiomyopathy (HOCM) (1963-82) comprises 137 patients, of whom 123 had typical HOCM and 14 atypical midventricular stenosis. Indications for surgery were unsatisfactory response to drug therapy and clinical symptoms according to at least functional class III (NYHA). The predominant approach for the relief of both types of HOCM was transaortic (112 cases; two deaths = 1.8%). The hospital mortality of the total series was 6.6% (nine of 137 patients). The most severe problems were caused by additional acquired mitral valve lesions. There is no special risk for patients with atypical midventricular HOCM. The systolic gradient between left ventricle and aorta could be removed or diminished in all cases.