Antero-posterior fluoroscopic view of bipolar catheter ablation from the left and right ventricular outflow tracts. A first ablation catheter is positioned in the left ventricular outflow tract via a retrograde, aortic approach (catheter A) and a second ablation catheter in the right ventricular outflow tract via a long sheath (catheter B). Both catheters are placed at sites of earliest activation in the respective outflow tracts. A third mapping catheter is situated high in the right ventricular outflow tract (catheter C). Bipolar ablation was performed between the distal tips of both ablation catheters (A and B) with one catheter acting as cathode, and the other as anode.