[Hypertrophic obstructive cardiomyopathy: surgical treatment].

Hypertrophic obstructive cardiomyopathy (HOCM) is an autosomal, dominant inherited disease of the myocardium which leads slowly to increasing subvalvular, septal and left ventricular hypertrophy and deterioration of systolic and diastolic left ventricular compliance. Difficult molecular-genetic investigations localized genetic defects on different chromosomes. The disease is pathological-anatomically characterized by asymmetric subvalvular (aortic) septal hypertrophy and left ventricular outflow tract obstruction resulting in additional left ventricular hypertrophy and dysfunction. Histologically the myocytes are hypertrophied, exhibit atypical branching (disarray), and there is a high amount of interstitial connective tissue. In our biopsy material (from myectomies) dysplasia could be detected in more than 30% of dysplastic intramural arteries with partly extential media. These changes may indicate microcirculatory disturbances resulting in arrhythmias, syncopes, sudden death, and anginal pain on the basis of microcirculatory disturbances and scar development. Today the discussion of DDD-pacemaker therapy has resumed, but one must wait for definite results, especially in patients in whom surgical treatment seems to be the best choice. The indication for surgical treatment, which usually is transaortic subvalvular myectomy (Morrow) and modifications, is very restrictive. Only patients in clinical degree III (NYHA) after long-term medical treatment are candidates for surgery. In some mainly younger patients the indication in lower clinical degrees was accepted because of a family history with sudden death and personal experience of syncope, life-threatening tachycardia, or after resuscitation. In the period 1963 to 1994 466 patients were operated upon. The mean age was 44.9 years (range 3 months to 82 years). Total early mortality was 4.9% (n = 12).(ABSTRACT TRUNCATED AT 250 WORDS)