Successful medical management of recurrent atrial arrhythmia in a non-eligible Fontan patient to ablation: case report and literature review

Introduction: A non-neglected subgroup of patients with Fontan circulation will develop arrhythmias during their lives, which may be due either to the underlying congenital heart disease itself or as a result of surgical or structural interventional treatment. Case presentation: We report the case of a 38-year-old woman, known to have a single ventricle congenital heart disease, at the age of 6, benefited from palliative correction by the intra-cardiac Fontan procedure and who, at the age of 35 years, developed focal intra-atrial tachycardia by macro reentry, who underwent ablation with complete isolation of the rest of the right atrium after Fontan fenestration. The evolution was marked by the onset of dyspnea with cyanosis requiring closure of the fenestration, as well as a recurrence of supra-ventricular arrhythmia that was successfully reduced by a triple association of maximum-dose metoprolol, maximum-dose diltiazem, and amiodarone. Discussion: In general, the management of intra-atrial tachycardia in Fontan is based on the following pillars: First, effective anticoagulation, then arrhythmia management by means of antiarrhythmic drugs, catheter ablation, anti-bradycardia and anti-tachycardia atrial pacing, and Fontan conversion with arrhythmia surgery. Although medical treatment is characterized by a high recurrence rate, it will be an important alternative when ablation is unavailable or not feasible for technical reasons of the type of montage performed. Conclusion: Arrhythmias represent one of the serious problems that the majority of patients with Fontan circulation will face at some time, and management of these arrhythmias remains essential given the compromise of hemodynamic function.