INDUCTION OF SUBAORTIC SEPTAL ISCHEMIA TO REDUCE OBSTRUCTION IN HYPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY - STUDIES TO DEVELOP A NEW CATHETER-BASED CONCEPT OF TREATMENT

Aim To develop a new catheter-based method of treatment in patients wi th hypertrophic obstructive cardiomyopathy Method Does abolition of th e blood supply to the subaortic part of the septum lead to regional my ocardial ischaemia and a decrease in the left ventricular outflow trac t gradient? To find this out, in 10 consecutive patients the first lar ger septal branch of the left anterior descending coronary artery was temporarily occluded with conventional percutaneous transluminal coron ary angioplasty. The intracoronary electrocardiogram was registered fo r objective verification of the intended ischaemia. The intraventricul ar pressure was measured at rest and at the post extrasystolic beat un der programmed electrostimulation of the right ventricle. Results Duri ng occlusion, regional ischaemia was observed in all patients. Simulta neously, there was a significant reduction of the intraventricular gra dient from 56.2 mmHg to 32.2 mmHg (P<0.05) followed by an increase fro m 32.2 mmHg to 61.1 mmHg (P<0.01) after release of occlusion of the se ptal branch. During ischaemia there was no increase in left ventricula r end-diastolic pressure. Conclusion We conclude that the results form the basis for a new catheter interventional therapy in hypertrophic o bstructive cardiomyopathy.