Tachyarrhythmia Following Norwood Operation

BACKGROUND: The purpose of this study was to characterize tachyarrhythmias in children following the Norwood procedure. METHODS: This is a single-center retrospective study including all children who underwent stage I Norwood procedure (n = 98; January 2003-September 2011). The primary outcome measure is the development of tachyarrhythmia during hospitalization after the Norwood procedure. Secondary aims include quantification of mortality in patients with tachyarrhythmias and evaluation of potential risk factors for the development of tachyarrhythmia. RESULTS: Tachyarrhythmia occurred in 33 (34%) of 98 patients. The median time to onset of tachyarrhythmia was ten days (0-47 days). Tachyarrhythmia conferred no increase in overall mortality (P = .45), including operative mortality (P = .37) or interstage mortality (P = 1.00). There was no significant difference in the incidence of arrhythmia based on demographic, anatomic, or surgical variables, including shunt type (P = .23) except that patients with tachyarrhythmias were slightly larger (median weight 3.2 kg) at the time of stage I than those without tachyarrhythmia (median weight 2.93 kg; P = .02]. The odds of arrhythmia in males were 8.7 times higher than that in females (95% confidence interval 2.9-31.3; P < .0001). CONCLUSIONS: Postoperative tachyarrhythmia is common, occurring in 34% of patients after the Norwood operation. Onset of tachyarrhythmia occurred later after the Norwood operation than reported previously, and male gender is a risk factor. Further studies to elucidate the etiology and the timing of tachyarrhythmias after the Norwood procedure are necessary.