[Hypertrophic obstructive cardiomyopathy: surgical therapy].

Surgical treatment of hypertrophic obstructive cardiomyopathy (HOCM), which may present in a typical (subaortic) or atypical (mid-ventricular) form, is indicated only after prior long-term drug treatment. The results obtained in 353 patients presenting with a symptomatic form of HOCM operated on between 1963 and 30 June 1991 are reported. The operative procedure took the form of transaortic subvalvular myectomy (TSM) as described by Morrow, modified by extending the myectomy. The patients comprised 210 males and 143 females aged between 6 and 76 years (average age 41.7 years). With few exceptions, all patients were in clinical stage III or IV (NYHA). The overall hospital mortality rate was 4.8% (n = 17); for TSM alone 3.1% (n = 8 out of 261 patients), for combination surgery with additional surgical measures 9.8% (n = 9 out of 92 patients). Among the last 194 patients (since 1984), the mortality rate was 2.06% (n = 4). To date, follow-up show an improvement in the symptoms and physical performance, and an annual mortality rate of about 1.8-4% among patients treated with drugs, and a post-operative mortality of about 1.1%, so that in HOCM patients with symptoms despite prior drug treatment, surgery can be recommended.