Basic problems and objective: In addition to medication with negative inotropic drugs, surgical myectomy and DDD pacemaker implantation are standard procedures in the treatment of hypertrophic obstructive cardiomyopathy (HOCM). In a preliminary series the results obtained with a recently described method, consisting of transcatheter myocardial reduction, are evaluated.
Patients and methods: Six patients (two women, four men; mean age 52.7 [44-68] years), who remained in moderate heart failure despite medical treatment, underwent the procedure. After atrial transseptal puncture (via a catheter introduced percutaneously into the femoral vein) the left ventricular outflow tract (LVOT) gradient was measured at rest and after 5-minute balloon occlusion of the first septal branch of the left coronary artery. After demonstration of significant reduction of the gradient by the occlusion, one (n = 3) or two (n = 3) septal branches were occluded by the injection of 2-5 ml of 96% alcohol.
Results: The LVOT gradient was reduced from 57.8 +/- 22.4 (38-97) mm Hg to 11.3 +/- 8.6 (0-21) mm Hg and postextrasystolic from 131.0 +/- 40.7 (78-198) mm Hg to 44.0 +/- 35.6 (19-69) mm Hg. All patients had angina for 24 hours after the procedure. Maximal rise in creatine kinase activity was 982 +/- 589 (392-1729) U/l after 8.0 +/- 3.9 (4-15) hours. In three patients transitory complete atrioventricular block developed 10 min to 5 days later, requiring temporary pacemaker implantation. The further course was without complication in all patients and they were discharged after 7.5 +/- 1.8 (6-11) days.
Conclusion: The described catheter method provides a nonsurgical means of reducing the amount of septal myocardium with subsequent reduction of the LVOT gradient in HOCM. Long-term observation in a larger group of patients and comparison with conventional forms of treatment are required to determined the method's ultimate place in the treatment of HOCM.