Abstract 9230: Arrhythmias After the Fontan Operation; Which is Superior: Intracardiac Lateral Tunnel or Extracardiac Conduit? An International Multicenter Study of 1271 Patients

Abstract

Background: Arrhythmias, both brady and tachyarrhythmias, are common after the Fontan operation for single ventricle. By avoiding surgery near the sinus node, reducing pressure overload of the right atrium (RA), and decreasing RA scarring, the extracardiac conduit (ECC) is thought to be less arrhythmogenic than the intracardiac lateral tunnel (ILT). Evidence of such superiority is, however, lacking or inconclusive. Methods: An international multi-center retrospective study of 1271 patients was performed comparing early and late bradyarrhythmia (defined as need for pacing) and tachyarrhythmia (defined as needing any acute or chronic anti-arrhythmic therapy) between 669 ECC and 602 ILT patients. Age at Fontan was ILT 2.8 +/- 2.2 vs ECC 3.5 +/- 2.2 (p<0.0001). Results: In the early post-operative period, bradyarrhythmias requiring pacing were noted in 83 (11%) ECC patients vs 24 (4%) ILT patients (p < 0.0001) and tachyarrhythmias were noted in 53 (8%) ECC patients vs 32 (5%) ILT (p=ns). At follow-up (FU) (ECC 4.8+/- 4 years Vs ILT 8.9 +/- 5.4, mean +/- SD p<0.0001)), bradyarrhythmias were seen in 39 (6%) ECC vs 62 (10%) ILT (P <0.003) and tachyarrhythmias in 23 (3%) ECC vs 58 (10%) ILT (p< 0.0001). However, when length of FU was factored in, the incidence of brady and tachyarrhythmias did not differ between the 2 groups (p=ns). Conclusions: ECC has a higher incidence of early bradyarrhythmias. When length of FU is accounted for, late arrhythmia burden is similar between the two groups. Overall, the ECC does not appear to be less arrhythmogenic than the ILT. Therefore, the decision of which type of Fontan to perform may best be based upon individual patient anatomy, hemodynamic factors and surgeon preference rather than on a desired decrease in arrhythmia burden from the ECC.