[Hypertrophic cardiomyopathy (HCM). Surgical versus drug therapy].

Hypertrophic cardiomyopathy (HCM) is a disease with different etiological, morphological, functional, clinical and therapeutic aspects. Recent investigations indicate that HCM is considerably widespread in the population (1:500). The causes seem to generate from familial or sporadic abnormalities (mutations). Depending on the clinical aspect, the complaints, and on the basis of morphologic and hemodynamic investigational results, we mainly have to consider two types of medical and surgical management. 1. Hypertrophic nonobstructive cardiomyopathy (HNCM) Patients may have no hemodynamic or morphologic deviations, but may be identified by familial moleculargenetic investigations. Others may have different types of rhythm disturbances which may indicate a higher risk of sudden death. Depending on the degree of hypertrophy, the clinical impairment indicates medical therapy with beta-blockers, Ca antagonists, and antiarrhythmic drugs. In the case of clinical deterioration and manifestation of myocardial insufficiency diuretics, digitalis, ACE inhibitors, and catecholamines are indicated. Further impairment may lead to heart transplantation or as a bridging procedure to implantation of a left ventricular or biventricular assist device until a suitable donor heart is available. 2. Hypertrophic obstructive cardiomyopathy (HOCM) Symptomatic patients may have different localizations of the left ventricular outflow tract obstruction (LVOTO) in the subaortic area (typical form) and in midventricular position of the LV (atypical form). The first therapeutic step is always medical therapy with beta-blockers, Ca antagonists, and antiarrhythmic drugs. Further deterioration toward clinical class III (NYHA) despite long-term medication until recently was generally accepted as indication for transaortic subvalvular myectomy (TSM). Today mostly two other techniques are preferred--if possible Double chamber pacing (DCP) (atrial triggered ventricular pacing), Transcoronary ablation of septal hypertrophy (TASH) (by selective injection of alcohol, 95%, into the first septal branch). Especially in younger patients, after syncope, life-threatening tachyarrhythmias, and after resuscitation, the implantation of a cardioverter defibrillator may be necessary. Comparative prospectively randomized studies between different therapeutic regimens for HOCM are not available. Retrospective analyses of patients after TSM show a considerable clinical improvement. The risk of sudden death is relatively low, but not excluded. Patients after TSM demonstrate advantages concerning the survival rate despite the more deteriorated condition against those after medical therapy only. According to the new interventional techniques, long-term results are not yet available, of course. However, the long-term results after TSM may serve as a comparative standard which have at least to be reached by DCP and/or TASH.