[Surgical treatment of hypertrophic cardiomyopathy; techniques, indications and results].

Many techniques have been proposed for the treatment of hypertrophic cardiomyopathy over the last 35 years: myotomy, septal myotomy-myectomy, isolated mitral valve replacement with a low profile prosthesis, cardiac transplantation. Usually, the patients referred for surgery are those who do not respond or are resistant to medical therapy (patients in NYHA classes III or IV). The usual indication for myomectomy is a significant subaortic gradient and major septal hypertrophy (> 18 mm). When mitral regurgitation is severe or organic, mitral valve replacement is associated. When septal hypertrophy is moderate (< 18 mm) or not evenly distributed, or after ineffective myomectomy, mitral valve replacement may be proposed. Cardiac transplantation is only considered when all medical and surgical possibilities have been exhausted. Analysis of the results of surgery (over 1,000 published cases) is hindered by the variability of the techniques employed, the indications and experience of the different groups. The operative mortality has significantly decreased (25% in the 1960s to 2 to 11% at present). The complications of myomectomy are mainly postoperative ventricular septal defects and atrioventricular block, some of which require implantation of a pacemaker. Peroperative transoesophageal echocardiography could help to reduce the operative risk even further. Surgery improves symptoms and increases exercise capacity. The benefits seem greater, more frequent and longer lasting than with medical therapy. Surgery should not, however, be considered to be curative as some patients remain at risk of developing symptoms related to physiopathological phenomena other than intraventricular obstruction (poor left ventricular filling, myocardial ischaemia, arrhythmias). Although some workers suggest improved survival, there have been no controlled trials on this subject.(ABSTRACT TRUNCATED AT 250 WORDS)