Endocardial radiofrequency ablation of septal hypertrophy. A new catheter-based modality of gradient reduction in hypertrophic obstructive cardiomyopathy.

Transcoronary alcohol ablation of septal hypertrophy (TASH) is a therapeutic catheter based option and an alternative to surgery in the treatment of patients with hypertrophic obstructive cardiomyopathy. However, the anatomic variability of the vascularisation of the obstructing septal bulge may limit the therapeutic efficacy. Thus, we examined an endocardial approach as an alternative. Based on the effects of radiofrequency energy in the treatment of cardiac arrhythmias this is the first report about the use of this modality. It refers to a 45-year-old patient with severe HOCM. The energy was applied by using a cooled-tip ablation catheter at the right side of the ventricular septum. The site corresponded to the obstructing area of the left ventricle. The following changes could be observed: a reduction of the intraventricular pressure gradient during the therapeutic session, a gradient reduction at cycle exercise as assessed by Doppler echocardiography 7 days after intervention, a subaortic septal hypokinesia, an enlargement of the left ventricular outflow tract, a reduction of the septal thickness and an increase in the exercise capacity using the 6-minute walk test. These changes are in accordance with the results after TASH and surgical treatment. The new modality might extend the possibilities in the catheter-based treatment of patients with severe HOCM.