Fig. 2
The voltage mapping of the atrium revealed two areas with critically slow conduction. One located posterosuperiorly between right atrial wall scar and the superior vena cava and the second area was between the right side of atrioventricular groove and the inferior vena cava. The patient had history of tricuspid atresia, pulmonary stenosis, bilateral modified Blalock Shunt and Fontan Procedure