Ablation of atrial tachyarrhythmias late after surgical correction of tetralogy of Fallot: long-term follow-up

Severe hypoxemia after radiofrequency ablation for atrial fibrillation in palliatively repaired tetralogy of Fallot: A case report

BACKGROUND

Patients with tetralogy of Fallot (TOF) often have arrhythmias, commonly being atrial fibrillation (AF). Radiofrequency ablation is an effective treatment for AF and does not usually cause severe postoperative hypoxemia, but the risk of complications may increase in patients with conditions such as TOF.

CASE SUMMARY

We report a young male patient with a history of TOF repair who developed severe hypoxemia after radiofrequency ablation for AF and was ultimately confirmed to have a new right-to-left shunt. The patient subsequently underwent atrial septal occlusion and eventually recovered.

CONCLUSION

Radiofrequency ablation may cause iatrogenic atrial septal injury; thus possible complications should be predicted in order to ensure successful treatment and patient safety.

Burden and Impact of Arrhythmias in Repaired Tetralogy of Fallot

PURPOSE OF REVIEW

Arrhythmias are a leading cause of morbidity and mortality following repair of tetralogy of Fallot (TOF). This review will highlight current understanding of arrhythmia pathogenesis in this patient population and review novel therapeutic options.

RECENT FINDINGS

Risk factors for developing ventricular arrhythmias in repaired TOF have thus far been better defined than for atrial arrhythmias. Growing understanding of the pathophysiology of arrhythmias, development of risk stratification models, and novel techniques such as electrophysiologic ultrahigh-density mapping should help to better identify patients that benefit from advanced therapies such as ablation and implantable cardioverter defibrillators. Atrial and ventricular arrhythmias are common in TOF patients. Methods of risk stratification and therapeutic approaches are rapidly evolving, leading to ever improving clinical outcomes in this patient population.

Current outcomes and treatment of tetralogy of Fallot

Tetralogy of Fallot (ToF) is the most common type of cyanotic congenital heart disease. Since the first surgical repair in 1954, treatment has continuously improved. The treatment strategies currently used in the treatment of ToF result in excellent long-term survival (30 year survival ranges from 68.5% to 90.5%). However, residual problems such as right ventricular outflow tract obstruction, pulmonary regurgitation, and (ventricular) arrhythmia are common and often require re-interventions. Right ventricular dysfunction can be seen following longstanding pulmonary regurgitation and/or stenosis. Performing pulmonary valve replacement or relief of pulmonary stenosis before irreversible right ventricular dysfunction occurs is important, but determining the optimal timing of pulmonary valve replacement is challenging for several reasons. The biological mechanisms underlying dysfunction of the right ventricle as seen in longstanding pulmonary regurgitation are poorly understood. Different methods of assessing the right ventricle are used to predict impending dysfunction. The atrioventricular, ventriculo-arterial and interventricular interactions of the right ventricle play an important role in right ventricle performance, but are not fully elucidated. In this review we present a brief overview of the history of ToF, describe the treatment strategies currently used, and outline the long-term survival, residual lesions, and re-interventions following repair. We discuss important remaining challenges and present the current state of the art regarding these challenges.