Case 1
A 50‐ year‐ old woman had intermittent palpitations for
several days and subsequently underwent electrophysiology study (EPS).
Both right and left femoral veins were accessed but the diagnostic
catheters could not be advanced to inferior vena cava (IVC). Venography
revealed anomalous venous drainage of both femoral veins into azygous
and hemiazygos veins with IVC agenesis. (Figure 1A and 1B). Owing to
small lumen of azygos veins, only one decapolar catheter could be
advanced through hemiazygos vein (via left subclavian vein to SVC) to
the coronary sinus (CS). Programmed stimulation was done via coronary
sinus pacing which confirmed the dual atrioventricular node conduction
and subsequently induced AVNRT (Figure 1C). Another vascular access was
established in the right internal jugular vein for the ablation
catheter. His bundle signal was recorded and mapped using the 3-D
mapping system (EnSite NavX system) (Figure 1D and 1E). Radiofrequency
energy was applied over the low Koch area with transient accelerated
junctional rhythm. Slow pathway was successfully eliminated and the
tachycardia was no longer inducible after the ablation.