Normally, the valve regresses by approximately 12 weeks gestation and leaves behind the crista terminalis
superiorly and the eustachian valve of the inferior vena cava and the thebesian valve of the coronary sinus inferiorly.
The predisposing factors for atrial arrhythmias following the Fontan procedure are extensive sutures performed on the right atrium resulting in healed non-conductive scar tissue, damage to the sinus node or the artery in previously performed hemi-Fontan procedures, injury to the crista terminalis
, extensive right atrial incisions performed in intracardiac repair operations, and multi-step operations (5-7).
Preparation involving crista terminalis
and trabecular area were perfused by Tyrode solution of the following composition (in mM): NaCl 136; KCl - 2.7; Ca[Cl.sub.2] - 1.8; MgS[O.sub.4] - 0.5; Na[H.sub.2]P[O.sub.4] 4.6; NaHC[O.sub.3]--up to pH=7.35; glucose--2 g/l; temperature--37 [+ or -] 0.5[degrees]C.