Sinus node dysfunction after intraatrial lateral tunnel and extracardiac conduit fontan procedures.

This study compares the effects of two techniques for the Fontan procedure-intraatrial lateral tunnel (IALT) and extracardiac conduit (ECC) -on sinus node dysfunction. Between January 1992 and December 1998, 54 patients underwent a total cavopulmonary connection Fontan procedure. Of these, 36 had follow-up 24-hour Holter recordings, and they constitute the population for this study. The 24-hour Holter recordings were performed between January 1998 and March 1999 and were evaluated for sinus node dysfunction and atrial tachycardia. Clinical follow-up (18 +/- 11 months for the IALT group vs 34 +/- 19 months for the ECC group; p = 0.002) and surface electrocardiograms were also reviewed. Among the 36 patients, 19 had an IALT and 17 had an ECC Fontan procedure. The incidence of sinus node dysfunction was 4/19 (21%) in the IALT group and 10/17 (59%) in the ECC group (p = 0.04). No patient from either group had an identified episode of atrial tachycardia. No permanent pacemaker was placed in the IALT group, whereas three were placed in the ECC group, all for sinus node dysfunction. In summary, patients with both IALT and ECC had an important incidence of sinus node dysfunction. The incidence of sinus node dysfunction was higher in the ECC group, which may have been due to longer follow-up in this group. Atrial tachycardia was not observed in either group. Although the IALT group had less sinus node dysfunction than the ECC group and appeared to require less permanent pacing, these data may be too limited to serve as the criteria for choosing between these two techniques for performing the Fontan procedure.