Catheter Ablation for Atrial Fibrillation in Adult Congenital Heart Disease: An International Multicenter Registry Study

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.

Atrial Fibrillation Ablation in Congenital Heart Disease: Therapeutic Challenges and Future Perspectives

The increasing prevalence of atrial fibrillation (AF) in adults with congenital heart disease raises significant questions regarding its management. The unique underlying anatomic and physiological background further adds to the difficulty in eliminating the AF burden in these patients. Herein, we provide an overview of the current knowledge on the pathophysiology and risk factors for AF in adult congenital heart disease, with a special focus on the existing challenges in AF ablation. Emerging imaging modalities and ablation techniques might have a role to play. Evidence regarding the safety and efficacy of AF ablation in adult congenital heart disease is summarized, especially for patients with an atrial septal defect, Ebstein anomaly of the tricuspid valve, tetralogy of Fallot, and Fontan circulation. Finally, any remaining gaps in knowledge and potential areas of future research are highlighted.

Atrial fibrillation in adult congenital heart disease and the general population

BACKGROUND

Atrial fibrillation (AF) in adult patients with congenital heart disease (ACHD) may appear early, depending on individual characteristics.

OBJECTIVES

The goals of this study were to investigate the epidemiological spectrum of AF in the entire cohort of ACHD and compare it with that in the general population.

METHODS

A retrospective study was performed in the nationwide cohort 2000-2014 with AF onset during 2003-2014.

RESULTS

In the cohort of ACHD, 2350 patients had AF; the incidence increased with age, plateauing around age 70. In patients aged 25-29, 45-49, 65-69, 75-79, and ≥80 years, the annual incidence was 1.3, 7.9, 20.6, 23.7, and 21.4/1000 per year, respectively. In the general population without CHD, 347,979 patients had AF; the annual incidence was <1/1000 per year in those aged <55 years but increased steadily with age (3.6, 8.6, and 14.2/1000 per year in aged 65-69, 75-79, and ≥80 years, respectively). Compared with individuals without ACHD, ACHD patients aged <50 years and those aged both 50-54 and 55-59 years exhibited a 20-fold and 10-fold higher incidence of AF, respectively. Patients with complex congenital heart disease and Ebstein's anomaly had the highest risk of AF (cumulative risk >10% by age 50 and >20% by age 60), followed by those with tetralogy of Fallot, tricuspid atresia, endocardial cushion defect, and secundum atrial septal defect (cumulative risk >5% by age 50 and >10% by age 60).

CONCLUSION

Compared with individuals without ACHD, AF in patients with ACHD likely appeared 30 years earlier, with a 10- to 20-fold higher incidence plateauing around age 70. Yet, incidence in individuals without ACHD continued to increase. AF burden in patients with ACHD is not expected to increase in a never-ending way.

Transseptal Puncture Guided by Three-Dimensional Electroanatomical Mapping: Early Experience Using a Simplified Approach in Adults with Congenital Heart Disease

AIMS

The widespread use of three-dimensional (3D) mapping systems and echocardiography in the field of cardiac electrophysiology has made it possible to perform transseptal punctures (TSP) with low or no fluoroscopy. However, such attempts in adults with congenital heart disease (ACHD) who have previously undergone surgical or interventional treatment are limited. Therefore, we sought to explore the feasibility and safety of an approach to perform zero- or low-fluoroscopy TSP in ACHD patients undergoing left atrial cardiac ablation procedures.

METHODS AND RESULTS

This study included 45 ACHD patients who underwent TSP for ablation of left-sided tachycardias (left atrium or pulmonary venous atrium). Computed tomography (CT) of the heart was performed in all patients prior to ablation. 3D mapping of the right-sided heart chambers before TSP was used to superimpose the registered anatomy, which was subsequently used for the mapping-guided TSP technique. TSP was performed with zero-fluoroscopy in 27 patients, and the remaining 18 patients had a mean fluoroscopy exposure of 315.88 ± 598.43 μGy.m² and a mean fluoroscopy duration of 1.9 ± 5.4 min. No patient in this cohort experienced TSP-related complications.

CONCLUSION

Our study describes a fluoroscopy-free or low-dose fluoroscopy approach for TSP in ACHD patients undergoing catheter ablation of left-sided tachyarrhythmias who had been previously treated surgically or interventionally due to congenital heart defects. By superimposing 3D electroanatomic mapping with cardiac CT anatomy, this protocol proved to be highly effective, feasible and safe.

Hidden problems in a case of atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia. However, the relation between congenital heart defects and the predisposition to AF is not fully understood. A 65-year-old male was admitted into the emergency department due to progressive dyspnea, orthopnea, palpitations, and edema. Transthoracic echocardiogram showed bi-atrial enlargement and dysplasia of the mitral leaflets with severe mitral regurgitation. Also, a membrane was noted in the LA, dividing the chamber into two parts, suggestive of cor triatriatum sinister. Coronary computed tomography angiography demonstrated a soft tissue septum in the left atrium. Multimodal evaluation is of vital importance for a complete approach, since, detected in time, it has an excellent prognosis.