Therapeutic approaches in symptomatic hypertrophic obstructive cardiomyopathy

Hypertrophic cardiomyopathy is a complex and heterogeneous disease. Althoug h most patients experience just a few symptoms, and have a good prognosis, there are others whose symptoms are severe and progressive, determined by d ifferent pathophysiological elements such as diastolic dysfunction, myocard ial ischemia, arrhythmias and subaortic obstruction. Approximately 20-30% o f hypertrophic cardiomyopathy patients develop an intraventricular dynamic gradient, which in some cases, is responsible for severe symptoms which are ameliorated once the obstruction is reduced. In many cases the symptoms ca n be controlled with medical treatment which includes betablockers, calcium -channel antagonists and dysopiramide, but some patients will still experie nce severe and refractory symptoms. This subgroup of patients, which repres ent approximately 5-10% of patients with hypertrophic cardiomyopathy, can b e problematic from a management perspective. For many years, septal myectom y and/or mitral valve replacement offered the only effective alternative th erapy for these patients. However, the high rates of morbidity and mortalit y associated with these procedures have necessitated the search for new and less invasive procedures such as ventricular pacing and percutaneous septa l ablation. Although the initial results with sequential pacing were encour aging, further studies have suggested a significant placebo effect, which m akes its application controversial. In the last 5 years selective embolizat ion of the septa[ artery precipitating a localized myocardial infarction ha s been utilized to reduce the subaortic gradient. The potential indications and efficacy of these new forms of treatment, like ventricular pacing and percutaneous septal ablation, are presently under evaluation and are the ma in subject of this review. Medical treatment, with either beta-blockers, calcium channel antagonists o r dysopiramide constitutes the first therapeutic step. Surgery, while allev iating the subaortic obstruction and reducing the intraventicular pressure and mitral insufficiency, produces important and long-lasting symptomatic a nd functional improvement in most of these patients, and it continues to be an important therapeutic alternative in these cases. If the first results with sequential pacemaker implants were encouraging, today it is alluded to an important placebo effect that causes its application to be controversia l. In the last 5 years the path has been made in the creation of a septal i nfarction located through the embolization of the septal branches to reduce the gradient.