Transthoracic percutaneous access for electroanatomic mapping and catheter ablation of atrial tachycardia in patients with a lateral tunnel Fontan

Ablation of intra-atrial reentrant tachycardias in adults with congenital heart disease: islands, isthmuses, channels, and walls

PURPOSE OF REVIEW

The adult congenital heart patient population is rapidly growing due to increasing survival rates, and they often face chronic physiologic challenges as sequalae of both their defects and repairs. Among the most common sequalae are arrhythmias. Here we describe intra-atrial reentrant tachycardia (IART), one of the most commonly seen arrhythmias in the adult congenital heart population, and the approaches to successful ablation in adult congenital heart patients.

RECENT FINDINGS

IART has increasing ablation success rates due to the increasing exposure of electrophysiologists to congenital cases, advances in technology, and the increasing application of both our pediatric congenital knowledge and adult acquired knowledge to the adult congenital population.

SUMMARY

IART is a frequently seen arrhythmia in the adult congenital population, and it can have life-threatening consequences in the setting of congenital disease. Ablation techniques and treatment rates have improved over time, despite the challenges these cases present to clinicians; success of the ablation depends on careful, often creative, preplanning, and understanding of the complex individualized anatomy and circuits of the patient.

Direct Percutaneous Transthoracic Cardiac Access for Recanalization of Longstanding Branch Pulmonary Artery Atresia

We describe the use of direct percutaneous cardiac access to recanalize an atretic right pulmonary artery in an adolescent with complex congenital heart disease and right heart failure. This case highlights the problems associated with loss of central venous access and potential advantages of a direct cardiac approach to catheterization. (Level of Difficulty: Intermediate.)

A novel procedure of puncture to access the pulmonary venous atrium in complex congenital heart disease with surgical correction

BACKGROUND

In complex congenital heart disease, supraventricular arrhythmia develops long term after surgical repair. The arrhythmia could have pharmacological tolerance and sometimes be fatal. We report our experiences with puncturing tough or calcified surgical repair material to access the pulmonary venous atrium for the purpose of the management of arrhythmia in complex congenital heart disease with surgical correction.

METHODS

From June 2016, subsequent 9 patients underwent the procedure. Their age at the procedure ranged from 11 to 43 years old (median 26.4 years old). Surgical procedures were Mustard procedure (Xenomedica^Ⓡ) in 6, lateral tunnel total cavo-pulmonary connection with autologous pericardium in 2, and extra-cardiac total cavo-pulmonary connection with expanded polytetrafluoroethylene (ePTFE) tube in 1.

RESULTS

Multi-planar reconstruction imaging by cardiac computed tomography was done for making plans before the procedures. Under intracardiac echocardiography guidance, an 8 French steerable sheath was perpendicularly adjusted to target objects. The sharpened edge of 0.014 inch guide wire penetrated with gentle forward force. Subsequently, the puncture site was dilated from a small balloon to a large one step by step. In all patients, penetration was successfully completed. Catheter ablation was achieved in 8 patients and a pacemaker was implanted through the re-canalized superior caval vein in 1 patient. No complications were recorded.

CONCLUSION

The trans-catheter puncture of the synthetic or calcified material is safe and feasible, although careful planning is required with imaging. A steerable sheath could easily be controlled to the make appropriate angle to the target object for preventing slippage and conveying effective force.

New developments in catheter ablation for patients with congenital heart disease

Introduction: There are numerous challenges to catheter ablation in patients with congenital heart disease (CHD), including access to cardiac chambers, distorted anatomies, displaced conduction systems, multiple and/or complex arrhythmia substrates, and excessively thickened walls, or interposed material. Areas covered: Herein, we review recent developments in catheter ablation strategies for patients with CHD that are helpful in addressing these challenges. Expert opinion: Remote magnetic navigation overcomes many challenges associated with vascular obstructions, chamber access, and catheter contact. Patients with CHD may benefit from a range of ablation catheter technologies, including irrigated-tip and contact-force radiofrequency ablation and focal and balloon cryoablation. High-density mapping, along with advances in multipolar catheters and interpolation algorithms, is contributing to new mechanistic insights into complex arrhythmias. Ripple mapping allows the activation wave front to be tracked visually without prior assignment of local activation times or window of interest, and without interpolations of unmapped regions. There is growing interest in measuring conduction velocities to identify arrhythmogenic substrates. Noninvasive mapping with a multielectrode-embedded vest allows prolonged bedside monitoring, which is of particular interest in those with non-sustained or multiple arrhythmias. Further studies are required to assess the role of radiofrequency needle catheters and stereotactic radiotherapy in patients with CHD.

Lateral tunnel Fontan atrial tachycardia ablation trans-baffle access is not mandatory as the initial strategy

BACKGROUND

Mapping and ablation of atrial tachycardia (AT) is commonly performed in lateral tunnel Fontan (LTF) patients, yet there is little information on the need of baffle puncture to access the pulmonary venous atrium (PVA). This study aimed to evaluate the most common chamber location of critical sites for majority of AT in LTF patients.

METHODS

Consecutive LTF patients underwent catheter-based high-density mapping and ablation of AT from Nov. 2015 to Mar. 2019. Critical sites were identified by a combination of activation and entrainment mapping. Acute procedural success was defined as AT termination with ablation and non-inducibility of any AT. Predictors for ablation failure were evaluated in retrospect.

RESULTS

Fifteen catheter ablation procedures were performed in 9 patients. A total of 15 clinical ATs (mean TCL 369 ± 91 ms) were mapped. The mechanism was macro re-entry in 11 (73%) and micro re-entry in 2. In 11 ATs (73%), 94 ± 5% of tachycardia cycle length (TCL) were mapped inside the tunnel. The commonest site of successful ablation in the tunnel was on the lateral wall (60%). Trans-baffle access was obtained during 5 of 15 procedures (33%). Overall, procedural success was achieved in 9 of 15 procedures (60%). There were no complications. Recurrence of AT was 42% over a follow-up period of 4.3 ± 3.2 years. Faster TCL of 200-300 ms showed a trend towards ablation failure, (OR 17, 95% CI 0.7 to 423, p = 0.08).

CONCLUSIONS

Catheter ablation can be performed effectively for ATs in LTF patients usually from inside the tunnel. ATs with critical sites in the PVA are uncommon. This information will help plan ablation in LTF patients without resorting to initial trans-baffle access.

Long Term Consequences of the Fontan Procedure and How to Manage Them

In 1971, Fontan and Baudet described a surgical technique for successful palliation of patients with tricuspid atresia. Subsequently, this technique has been applied to treat most forms of functional single ventricles and has become the current standard of care for long-term palliation of all patients with single ventricle congenital heart disease. Since 1971, the Fontan procedure has undergone several variations. These patients require lifelong management including a thorough knowledge of their anatomic substrate, hemodynamic status, management of rhythm and ventricular function along with multi organ evaluation. As these patients enter middle age, there is increasing awareness regarding the long-term complications and mortality. This review highlights the long-term outcomes of the Fontan procedure and management of late sequelae.

Atrial Fibrillation in Patients with Congenital Heart Disease

Advances in surgical techniques have led to the survival of most patients with congenital heart disease (CHD) up to their adulthood. During their lifetime, many of them develop atrial tachyarrhythmias due to atrial dilatation and scarring from surgical procedures. More complex defects and palliative repairs are linked to a higher incidence and earlier occurrence of arrhythmias. Atrial fibrillation (AF) is common in patients who have atrial septal defects repaired after age 55 and in patients with tetralogy of Fallot repaired after age 45. Patients with dextrotransposition of the great arteries who undergo Mustard or Senning atrial switch procedures have an increased risk of atrial flutter due to atrial baffle suture lines. Patients with Ebstein's anomaly are also prone to supraventricular tachycardias caused by accessory bypass tracts. Patients with a single ventricle who undergo Fontan palliation are at risk of developing persistent or permanent AF due to extreme atrial enlargement and hypertrophy. In addition, obtaining vascular access to the pulmonary venous atrium can present unique challenges during radiofrequency ablation for patients with a Fontan palliation. Patients with cyanotic CHD who develop AF have substantial morbidity because of limited hemodynamic reserve and a high viscosity state. Amiodarone is an effective therapy for patients with arrhythmias from CHD, but its use carries long-term risks for toxicity. Dofetilide and sotalol have good short-term effectiveness and are reasonable alternatives to amiodarone. Pulmonary vein isolation is associated with better outcomes in patients taking antiarrhythmic medications. Anticoagulants are challenging to prescribe for patients with CHD because of a lack of data that can be extrapolated to this patient population. Surgical ablation is the gold standard for invasive rhythm control in patients with CHD and should be considered at the time of surgical repair or revision of congenital heart defects. When possible, patients with complex CHD should be referred for care to an adult congenital heart disease center of excellence.

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.

Tachyarrhythmias and catheter ablation in adult congenital heart disease

Advances in surgical technique have had an immense impact on longevity and quality of life in patients with congenital heart disease. However, an inevitable consequence of these surgical successes is the creation of a unique patient population whose anatomy, surgical history and haemodynamics result in the development of a challenging and complex arrhythmia substrate. Furthermore, this patient group remains susceptible to the arrhythmias seen in the general adult population. It is through a thorough appreciation of the cardiac structural defect, the surgical corrective approach, and haemodynamic impact that the most effective arrhythmia care can be delivered. Catheter ablation techniques offer a highly effective management option but require a meticulous attention to the real-time integration of anatomical and electrophysiological information to identify and eliminate the culprit arrhythmia substrate. This review describes the current approach to the interventional management of patients with tachyarrhythmias in the context of congenital heart disease.

Transbaffle mapping and ablation for atrial tachycardias after mustard, senning, or Fontan operations

Background

In Fontan and atrial switch patients, transcatheter ablation is limited by difficult access to the pulmonary venous atrium. In recent years, transbaffle access (TBA) has been described, but limited data document its safety and utility.

Methods and Results

All ablative electrophysiological study cases of this population performed between January 2006 and December 2010 at Boston Children's Hospital were reviewed. Pre‐case and follow‐up clinical characteristics were documented. Adverse events were classified by severity and attributability to the intervention. We included 118 cases performed in 90 patients. TBA was attempted in 74 cases and was successful in 96%: in 20 via baffle leak or fenestration and in 51 (94%) of 54 using standard or radiofrequency transseptal techniques. There were 10 procedures with adverse events ranked as moderate or more severe. The event rate was similar in both groups (TBA 8% versus non‐TBA 9%, P=1), and no events were directly attributable to TBA. There was a trend to higher proportion of cases having a >5‐point drop in saturations from baseline in the TBA group versus the non‐TBA group in Fontan cases (15% vs 0%, P=0.14). When cases with follow‐up >90 and >365 days were analyzed, the median initial arrhythmia score of 5 significantly changed −3 points in both time periods (P≤0.001).

Conclusions

TBA is feasible in this population; its use was not associated with a higher incidence of adverse events; and changes in clinical scores support its efficacy. Desaturation observed in some patients is of uncertain significance but warrants postablation monitoring and prospective study.

Hybrid Access to Atria via the Guiraudon Universal Cardiac Introducer for Arrhythmia Ablation after Total Cavopulmonary Derivation

We report the first use of a new platform, the Guiraudon Universal Cardiac Introducer (GUCI), in humans for accessing the left atrium for catheter-based ablations in patients with resistant atrial arrhythmias after total cavopulmonary derivation. The GUCI was originally designed for intracardiac access for closed, beating instrumental intracardiac surgery.

The patient was a 29-year-old man with problematic atrial arrhythmias resistant to antiarrhythmic drugs because of severe uncontrolled bradycardia and because his pacemaker was explanted for infection.

The GUCI was attached to the left atrial appendage via an anterior left thoracotomy. The GUCI was modified to accommodate introduction and manipulation of multiple catheters. This allowed electrophysiologists to perform catheter-based exploration and ablation. A DDD pacemaker was implanted, with an atrial endocardial lead introduced via the GUCI cuff and a ventricular epicardial lead.

Postoperative atrial arrhythmias were controlled using amiodarone and atrial pacing. At the 12-month follow-up, the patient was arrhythmia- and drug-free and returned to full employment.

This new access offers an additional new alternative atrial access to treat resistant arrhythmia after total cavopulmonary derivation. The current state-of-the-art makes patient selection difficult and uncomfortable for the surgeons because of incomplete preoperative electrophysiological data, such as a return to the beginning of surgery for arrhythmia; however, more cumulative experience with intraoperative electrophysiological data and new mapping technologies should address these limitations.

Nodoventricular pathway associated with twin AV nodes: complexity of ablation in single ventricle physiology

We report the case of a patient with heterotaxy syndrome including complex single ventricular morphology and interrupted IVC in association with twin conduction systems and a nodoventricular accessory pathway connection. The presence of 3 distinct QRS morphologies was inadvertently discovered during a hemodynamic catheterization study and prompted formal EP testing prior to hepatic venous inclusion into the Fontan circuit and loss of access to the atrial chamber for testing and therapy. This patient underscores the importance of close surveillance and high index of suspicion of arrhythmia mechanisms in patients with heterotaxy syndrome in conjunction with single ventricle morphology.

A transbaffle approach to ablation in a child with an extracardiac fontan

We present the case of an 11-year-old with D-transposition, double inlet left ventricle, and dextrocardia 8 years following an extracardiac Fontan with supraventricular tachycardia mediated by a concealed accessory pathway. A transbaffle puncture was performed with fluoroscopic and transesophageal echocardiography guidance and the pathway location as well as its proximity to the HIS bundle were identified. The pathway was successfully ablated and the patient is asymptomatic for 12 months postablation.