Catheter ablation of the atrioventricular junction and activity responsive pacing. Effect on refractory atrial fibrillation with hypertrophic cardiomyopathy.

A 50-year-old man had chronic atrial fibrillation that was refractory to conventional therapy. He was intolerant of amiodarone, but successfully managed by transcatheter atrioventricular junction ablation. Activity-initiated rate-responsive ventricular pacing resulted in a fourfold greater increase in cardiac output with exercise compared to fixed rate pacing.