Comparison of electrophysiologic effects of propofol and isoflurane-based anesthetics in children undergoing radiofrequency catheter ablation for supraventricular tachycardia

Background: Radiofrequency catheter ablation (RFCA), which is typically performed with general anesthesia in children, is an interventional therapy for tachyarrhythmia. Although the electrophysiologic (EP) effects of isoflurane- and propofol-based anesthetics have been shown to be similar, a retrospective analysis reported significantly longer RFCA procedural duration with the use of isoflurane. It remains unclear whether the ability to successfully perform RFCA differs between these drugs. Methods: Patients were randomly assigned to receive either an isoflurane- or propofol-maintained anesthetic. Drug administration was titrated according to the pharmacodynamic end-point of depth of sedation using bispectral index score. The ability to induce sustained tachycardia (using a scoring system), procedural durations, and effects on cardiac electrophysiologic properties were evaluated and compared between the groups. Results: Sixty subjects were included in this study. Sustained supraventricular tachycardia (SVT) was inducible with the assigned drug in all but four subjects. In three of these four subjects, SVT was also not inducible with the alternative study drug. Ability to induce the first sustained SVT was similar between the groups (P = 0.83). Total procedural durations were similar (isoflurane 224 +/- 84 min vs. propofol 221 +/- 86 min, mean +/- SD, P = 0.88). Atrioventricular nodal conduction was slower with propofol compared with isoflurane, but this result did not appear to be clinically relevant. Finally, ventricular repolarization was prolonged by isoflurane versus propofol, the clinical significance of which was not demonstrated. Conclusion: Isoflurane- and propofol-based anesthesia were equally suitable in children and adolescents undergoing RFCA.