Optimal timing of the Fontan conversion: Change in the P-wave characteristics precedes the onset of atrial tachyarrhythmias in patients with atriopulmonary connection

ObjectivesAtrial tachyarrhythmia is a common complication late after the atriopulmonary connection Fontan procedure. The P-wave duration and dispersion have been regarded as useful markers for its prediction. The purpose of this study was to analyze change in the P-wave characteristics over time after the atriopulmonary connection Fontan procedure, with a special emphasis on the timing of the Fontan conversion.MethodsWe reviewed clinical and electrocardiographic data in 18 patients with classic tricuspid atresia who underwent the atriopulmonary connection Fontan procedure. Their median age at operation was 4.1 years (range, 1.1–22 years), and the median follow-up period was 18.1 years (range, 10-25 years). We measured the P-wave duration, dispersion, and axis from consecutive 12-lead electrocardiograms in each patient.ResultsThere was a significant increase in the maximum P-wave duration as well as the P-wave dispersion over time. Transient ectopic atrial rhythm was observed in 16 patients during follow-up. Atrial tachyarrhythmia developed subsequent to transient ectopic atrial rhythm in 8 patients. Ten patients underwent the conversion. Atrial tachyarrhythmia recurred in 2 patients who had sustained arrhythmia (6.0 and 8.0 years) before the conversion. In contrast, the other 8 patients with transient ectopic atrial rhythm alone or nonsustained atrial tachyarrhythmia have been free from arrhythmia after the conversion.ConclusionsPatients commonly and increasingly had prolonged P-wave duration, larger P-wave dispersion, and ectopic atrial rhythm, along with an atrial tachyarrhythmia propensity, late after the atriopulmonary connection Fontan procedure. These P-wave characteristics were informative when considering the Fontan conversion before a sustained atrial tachyarrhythmia ensued