Fig-9; During induced orthodromic AVRT most fused AV was seen in CS 1,2.
Baseline intervals during sinus were as follows: sinus cycle length 830 msec, atrial His (AH) interval 90 msec, and His-ventricular (HV) interval 20 msec, AV-WP 250 msec, VA-WP 240 msec. RA activation recorded the earliest retrograde activations in the CS 1,2 region (Fig-8), so septostomy was done via 8 F catheter and Rf energy was applied at left posterior side of MV annulus but not resulted in VA dissociation.
Because of exaggerated motions of CS catheter, a sheath was inserted in LT subclavian vein and contrast was injected in left SVC and disappeared a dilated CS (Fig-10). Therefore, broad mapping was done in CS and RA again.