Catheter ablation of tachycardia arising from the pulmonary venous atrium after surgical repair of congenital heart disease

Pulmonary vein and left atrial posterior wall isolation for the treatment of atrial fibrillation: Comparable outcomes for adults with congenital heart disease

INTRODUCTION

Optimal treatment strategies for ACHD with AF are unknown. This study sought to assess outcomes of pulmonary vein isolation (PVI) ± left atrial (LA), posterior wall isolation (PWI) for adults with congenital heart disease (ACHD), and atrial fibrillation (AF).

METHODS

A retrospective review of all cryoballoon (CB) PVI ± PWI procedures at a single center over a 3-year period were performed. Clinical characteristics and outcomes for patients with and without ACHD were compared. The primary outcome was the occurrence of atrial tachyarrhythmia at 12-months postablation after a 90-day blanking period.

RESULTS

Three-hundred and sixteen patients (mean: 63 ± 12 years, [63% male]) underwent CB PVI ± PWI during the study, including 31 (10%) ACHD (simple 35%, moderate 39% complex 26%; nonparoxysmal AF in 52%). ACHD was younger (51 vs. 64 years; p < .001) with a lower CHADS₂ DS₂ -VASc score (1.2 vs. 2.1; p = .001) but had a greater LA diameter (4.9 vs. 4.0 cm; p < .001) and a number of prior cardioversions (0.9 vs. 0.4; p < .001) versus controls. 12-month freedom from recurrent AF was similar for ACHD and controls (76% vs. 80%; p = .6) and remained nonsignificant in multivariate analysis (hazard ratio: 1.8, 95% confidence interval: 0.7-5.1; p = .22). At 12-months postablation, 75% of ACHD versus 93% of control patients were off antiarrhythmic drug therapy (p = .07).

CONCLUSION

This study demonstrates younger age and lower conventional stroke risk, yet clinically advanced AF for ACHD relative to controls. CB PVI ± PWI was an effective strategy for the treatment of AF among all forms of ACHD with similar 12-month outcomes as compared to controls.

Radiofrequency Catheter Ablation of Atrial Tachycardias in Congenital Heart Disease

Background

Radiofrequency catheter ablation has become the treatment strategy of choice for atrial tachyarrhythmias in patients with congenital heart disease (CHD). We analyzed results of radiofrequency catheter ablation in a large cohort of patients with CHD with special reference to complexity of underlying anatomy.

Methods and Results

One hundred and forty-four patients with CHD and atrial tachyarrhythmias undergoing radiofrequency catheter ablation were classified according to complexity of underlying CHD: simple CHD, n=18 (12%); moderate CHD, n=53 (37%); and complex CHD, n=73 (51%). Overall acute success was achieved in 81% of the patients. Acute success was lower for tachycardias involving the left atrium compared with right atrial tachycardias. Complexity of CHD was associated with longer procedure duration. Tachycardia recurrence was observed in 54% of the patients after a total follow-up of 7.4 years. 75% of all recurrences occurred within the first year. Recurrence of tachycardia was more likely in patients with complex surgical atrial anatomy (ie, Fontan palliation or atrial switch procedure). Major complications occurred in 4 patients and were related to vascular access.

Conclusions

Acute procedural success of atrial tachycardia ablation in congenital heart patients was not influenced by complexity of CHD. Long-term outcome with regard to tachycardia recurrence was worse in patients with complex surgical atrial anatomy.

Supraventricular Arrhythmias in Patients with Adult Congenital Heart Disease

An increasing number of patients with congenital heart disease survive to adulthood; such prolonged survival is related to a rapid evolution of successful surgical repairs and modern diagnostic techniques. Despite these improvements, corrective atrial incisions performed at surgery still lead to subsequent myocardial scarring harbouring a potential substrate for macro-reentrant atrial tachycardia. Macroreentrant atrial tachycardias are the most common (75 %) type of supraventricular tachycardia (SVT) in patients with adult congenital heart disease (ACHD). Patients with ACHD, atrial tachycardias and impaired ventricular function - important risk factors for sudden cardiac death (SCD) - have a 2-9 % SCD risk per decade. Moreover, ACHD imposes certain considerations when choosing antiarrhythmic drugs from a safety aspect and also when considering catheter ablation procedures related to the inherent cardiac anatomical barriers and required expertise. Expert recommendations for physicians managing these patients are therefore mandatory. This review summarises current evidence-based developments in the field, focusing on advances in and general recommendations for the management of ACHD, including the recently published recommendations on management of SVT by the European Heart Rhythm Association.

Management of supraventricular arrhythmias in adults with congenital heart disease

Supraventricular arrhythmias are a frequent complication in adults with congenital heart disease (ACHD). The prevalence increases with time since surgery, complexity of the underlying defect, type of repair and older age at surgery. Arrhythmias are the most frequent reason for hospital admission and along with heart failure the leading cause of death. The arrhythmia-associated increase in morbidity and mortality makes their management a key task in patients with ACHD. Intra-atrial re-entry is the most frequent arrhythmia mechanism. Less common arrhythmia mechanisms are supraventricular tachycardias in the presence of an accessory pathway, atrioventricular nodal re-entrant tachycardia or focal tachycardias. Patient management includes stroke prevention, acute termination and prevention of arrhythmia recurrence. Acute treatment depends on patients' symptoms. In cases of haemodynamic instability, immediate cardioversion is warranted. For stable patients, acute treatment includes rate control and termination by antiarrhythmic drugs or electrical cardioversion. Following a symptomatic arrhythmia, catheter ablation or treatment with antiarrhythmic drugs is recommended to prevent recurrences. Advances in mapping and ablation technology are now associated with high success rates of catheter ablation. In patients with a complex substrate recurrence rates of 50% remain high. However, in the presence of side effects and complications associated with long-term antiarrhythmic drug therapy, redo procedures are encouraged by current guidelines.

Transbaffle catheter ablation of atrial re-entrant tachycardia within the pulmonary venous atrium in adult patients with congenital heart disease

AIMS

Catheter ablation of atrial re-entrant tachycardia in patients after atrial switch procedure for transposition of the great arteries or with a Fontan circulation is technically challenging if the critical part of the re-entry circuit is located within the pulmonary venous atrium (PVA). We report our experience in transbaffle access (TBA) to the PVA for ablation of atrial re-entrant tachycardia focusing on technical details.

METHODS AND RESULTS

In eight patients, six after Mustard procedure and two with a Fontan circulation, endocardial mapping of atrial re-entrant tachycardia revealed the critical part of the re-entry circuit within the PVA. A total of 10 ablation procedures were performed. Detailed angiographic assessment of the anatomy of the systemic and pulmonary venous atria was performed prior to baffle puncture. Transbaffle access was successfully established with a standard transseptal needle in 9 of 10 procedures. No major complications occurred. At the end of the procedure and the removal of the transseptal sheath, there was no residual shunt in any patient.

CONCLUSION

Transbaffle access to the PVA for ablation of atrial re-entrant tachycardia is feasible, less invasive than alternative approaches and can be safely applied in patients after Mustard procedure or with a Fontan circulation. However, the rigidity of prosthetic material may preclude baffle puncture at least in a subset of those patients.

Transcaval Puncture for Access to the Pulmonary Venous Atrium After the Extracardiac Total Cavopulmonary Connection Operation

Background—

Patients with surgically palliated total cavopulmonary connection are at risk for recurrent atrial arrhythmia requiring catheter ablation. Transcatheter procedures for those with extracardiac conduits (extracardiac-total cavopulmonary connection) are perhaps the most challenging because of exclusion of the venous circulation from the arrhythmia substrate. Puncture through the inferior vena cava to the pulmonary venous atrium may be an effective route for access in these patients.

Methods and Results—

The pediatric and adult congenital surgical databases were explored for patients with extracardiac-total cavopulmonary connection and postoperative computed tomography imaging to assess for the presence of clinically relevant (>3 mm) apposition between the inferior vena cava and pulmonary venous atrium (cavoatrial overlap). The degree of overlap between the structures was measured by 2 blinded reviewers. Patients were stratified by surgical repair in childhood versus adult congenital heart disease. Thirty-seven patients were identified, with cavoatrial overlap observed in 9 (36%) of pediatric and 1 (9%) of adult congenital heart disease–repaired patients. Time elapsed after surgery was associated with cavoatrial overlap in the pediatric cohort ( P =0.034) and was identified in all pediatric patients with computed tomography imaging ≥8 years after surgery. Three patients underwent successful transcaval puncture during the study period without complication.

Conclusions—

Puncture through a region of overlap between the inferior vena cava and pulmonary venous atrium is feasible. Cavoatrial overlap is present in a substantial proportion of patients undergoing extracardiac-total cavopulmonary connection in childhood and is associated with a longer time elapsed since surgery.