Hypertrophic cardiomyopathy (HCM). Surgical versus medical therapy

Hypertrophic cardiomyopathy (HCM) is a disease with different etiological, morphological, functional, clinical and therapeutic aspects. Recent investi gations indicate that HCM is considerably widespread in the population (1:5 00). The causes seem to generate from familial or sporadic abnormalities (m utations). Depending on the clinical aspect, the complaints, and on the bas is of morphologic and hemodynamic investigational results, we mainly have t o consider two types of medical and surgical management. 1. Hypertrophic nonobstructive cardiomyopathy (HNCM) Patients may have no h emodynamic or morphologic deviations, but may be identified by familial mol eculargenetic investigations. Others may have different types of rhythm dis turbances which may indicate a higher risk of sudden death. Depending on th e degree of hypertrophy, the clinical impairment indicates medical therapy with beta-blockers, Ca antagonists, and antiarrhythmic drugs. In the case o f clinical deterioration and manifestation of myocardial insufficiency diur etics, 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 obstruct ion (LVOTO) in the subaortic area (typical form) and in midventricular posi tion of the LV (atypical form). The first therapeutic step is always medica l therapy with beta-blockers, Ca antagonists, and antiarrhythmic drugs. Further deterioration toward clinical class III (NYHA) despite long-term me dication until recently was generally accepted as indication for transaorti c subvalvular myectomy (TSM). Today mostly two other techniques are preferred - if possible - Double cham ber pacing (DCP) (atrial triggered ventricular pacing), - Transcoronary abl ation of septal hypertrophy (TASH) (by selective injection of alcohol, 95 % , into the first septal branch) Especially in younger patients, after syncope, life-threatening tachyarrhyt hmias, and after resuscitation, the implantation of a cardioverter defibril lator may be necessary. Comparative prospectively randomized studies between different therapeutic regimens for HOCM are not available. Retrospective analyses of patients aft er TSM show a considerable clinical improvement. The risk of sudden death i s relatively low, but not excluded. Patients after TSM demonstrate advantag es concerning the survival rate despite the more deteriorated condition aga inst those after medical therapy only. According to the new interventional techniques, long-term results are not y et 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.