We here report on the PTSMA results in four HOCM patients having severe symptoms despite medical treatment and dual chamber pacing. Between two and five ml of ethanol was injected in one or two septal branches from the left coronary artery. Six months after treatment the pressure gradient across the left ventricular outflow tract was reduced between 25-80 mmHg at rest and between 55-180 mmHg at exercise. There was an increase in functional capacity of about two NYHA-classes. Two patients developed permanent right bundle branch block, and one patient with pre-existing left bundle branch block developed persistent total atrioventricular block after the treatment. Serum creatine phosphokinase MB increased on average to 146 U/l. No other complications were seen. In conclusion, our initial PTSMA results seems promising.