Figure 2.

A, Left anterior oblique fluoroscopic view of a right posteroseptal accessory pathway ablation. ABL: ablation catheter at the ninth electrode of the CS catheter, which was located at the coronary sinus os. All multielectrode catheter poles are labeled by convention in numerical order starting at the distal (tip) electrode. CS, coronary sinus decapolar catheter; His, decapolar catheter with the tip electrodes located at the His bundle region. RV, quadripolar catheter located in the right ventricle. B, Left anterior oblique fluoroscopic view of a left anterior accessory pathway ablation. ABL, ablation catheter that has been prolapsed retrograde across the aortic valve and is deflected under the septal mitral valve leaflet. CS, coronary sinus decapolar catheter. His, decapolar catheter with the tip electrodes originally located at the His bundle region; however, it had flipped away from the septum at the time of this image. RV, quadripolar catheter located in the right ventricle