Magnetic Navigation and Catheter Ablation of Right Atrial Ectopic Tachycardia in the Presence of a Hemi-Azygos Continuation: A Magnetic Navigation Case Using 3D Electroanatomical Mapping

Robotic magnetic-guided catheter ablation in patients with congenital heart disease: a systematic review and pooled analysis

BACKGROUND

Robotic magnetic navigation (RMN) has emerged as a potential solution to overcome challenges associated with catheter ablation of arrhythmias in patients with congenital heart disease (CHD).

OBJECTIVES

To assess safety and efficacy of RMNguided catheter ablation in patients with CHD.

DESIGN AND METHODS

A systematic review and pooled analysis was conducted on patients with CHD who underwent RMNguided catheter ablation. Random effects models were used to generate pooled estimates with the inverse variance method used for weighting studies.

RESULTS

Twentyfour nonoverlapping records included 167 patients with CHD, mean age 36.5 years, 44.6% female. Type of CHD was simple in 27 (16.2%), moderate in 32 (19.2%), and complex in 106 (63.5%). A total of 202 procedures targeted 260 arrhythmias, the most common being macroreentrant atrial circuits. The mean procedural duration was 207.5 minutes, with a mean fluoroscopy time of 12.1 minutes. The pooled acute success rate was 89.2% [95% CI (77.8%, 97.4%)]. Freedom from arrhythmia recurrence was 84.5% [95% CI (72.5%, 94.0%)] over a mean follow-up of 24.3 months. The procedural complication rate was 3.5% with no complication attributable to RMN technology.

CONCLUSION

RMN-guided ablation appears to be safe and effective across a variety of arrhythmia substrates and types of CHD.

Catheter Ablation: General Principles and Advances

Besides antiarrhythmic medication, there are now very good options for a potentially curative therapy by catheter ablation targeting the origin of the underlying arrhythmias in patients with complex congenital heart disease. Three-dimensional (3D) reconstruction of tomographic imaging (MRI or computed tomography) is helpful to understand the underlying cardiac anatomy, identify the most likely target chamber, and help with planning access. Use of the available 3D mapping systems (sequential or simultaneous acquisition) and (if available) more advanced navigation systems, such as remote magnetic navigation, can improve the acute and long-term outcomes of catheter ablation in congenital heart disease.

[Arrhythmia in adults with congenital heart defects : Atrial tachycardia]

Atrial arrhythmias are frequently encountered in patients with congenital heart disease (CHD) with or without corrective surgery and respond to pharmacological therapies with only limited success. This review describes the technologies currently available for performing successful ablation procedures in this very complex patient cohort. In addition to an understanding of the underlying anatomy, which can be supplemented by 3D imaging with the aid of magnetic resonance imaging (MRI) or computed tomography (CT), the choice between the different 3D mapping systems (sequential versus simultaneous) is presented. Finally, conventional manual navigation is compared with magnetic navigation and then discussed with regard to the respective arrhythmias encountered with the different forms of CHD.

Remote Navigation for Complex Arrhythmia

Magnetic navigation has been established as an alternative to conventional, manual catheter navigation for invasive electrophysiology interventions about a decade ago. Besides the obvious advantage of radiation protection for the operator who is positioned remotely from the patient, there are additional benefits of steering the tip of a very floppy catheter. This manuscript reviews the published evidence from simple arrhythmias in patients with normal cardiac anatomy to the most complex congenital heart disease. This progress was made possible by the introduction of improved catheters and most importantly irrigated-tip electrodes.

[A patient without intracardiac ECG. Persistent azygos vein]

Interruption of inferior vena cava with azygos continuation is a rare venous anomaly. We report the case of a 17 old male with Wolf-Parkinson-White syndrome and a persistent vena azygos. Despite the complex anatomical situation, it was possible to safely ablate a lateral accessory pathway with radiofrequency energy using a femoral retrograde approach.

Advanced ablation strategies for management of post-surgical atrial arrhythmias

Post-surgical arrhythmias include a wide range of arrhythmias occurring late after cardiac surgery and represent a complex substrate for catheter ablation either because of extended scar and remodeling or because of limited access to the area of interest. Novel image integration and ablation tools have made the catheter ablation in this population both feasible and successful. We review a structured approach to catheter ablation of post-surgical atrial arrhythmias in various patient cohorts including the most common congenital heart defects.

Multiple cardiac perforations following radiofrequency catheter ablation: case report and literature reviews

INTRODUCTION

Multiple cardiac ruptures after radiofrequency catheter ablation that requires surgical repair are uncommon.

METHODS AND RESULTS

We describe a 64-year old male patient with paroxysmal atrial fibrillation who had a cardiac tamponade following radiofrequency ablation. Surgical exploration demonstrated two ruptures in the left atrium, one in the right atrium, and one hematoma in the right atrium. MEDLINE, the Cochrane Library, and related databases were searched up to June 2011 without language restrictions, and related literature was reviewed and discussed. The patient has survived from prompt cardiac repair of cardiac ruptures and recovered from surgery without complications.

CONCLUSIONS

Urgent exploratory surgery with cardiopulmonary bypass is the key to salvage the patient.

Systemic venous anatomy in congenital heart disease: implications for electrophysiologic testing and catheter ablation

INTRODUCTION

Cardiac arrhythmias are a significant problem in patients with congenital heart disease. Many patients with congenital heart disease have abnormal systemic venous anatomy which can complicate electrophysiologic testing, catheter ablation and pacemaker and defibrillator implantation. We reviewed the systemic venous anatomy in a cohort of patients undergoing electrophysiologic testing and catheter ablation.

METHODS AND RESULTS

We reviewed all electrophysiologic studies performed in patients with adult congenital heart disease (n = 80) at our institution between January 1998 and October 2009. Ten patients (13%) had a congenital systemic venous anomaly. Of these, seven (9%) had a left superior vena cava and four (5%) had infrahepatic interruption of the inferior vena cava (two had both anomalies). One patient's inferior vena cava was connected to a left-sided atrium; she had right atrial isomerism. In four patients (40%), systemic venous abnormalities were discovered at the time of electrophysiologic testing.

CONCLUSIONS

Systemic venous anomalies occur frequently in the congenital heart disease population and may complicate electrophysiologic testing and catheter ablation. Pre-procedural imaging may assist in facilitating a successful procedure.

[Magnetic navigation for ablation of cardiac arrhythmias]

BACKGROUND

The first use of magnetic navigation for radiofrequency ablation of supraventricular tachycardias, was published in 2004. Subsequently, the method has been used for treatment of most types of tachyarrhythmias. This paper provides an overview of the method, with special emphasis on usefulness of a new remote-controlled magnetic navigation system.

MATERIAL AND METHODS

The paper is based on our own scientific experience and literature identified through a non-systematic search in PubMed.

RESULTS

The magnetic navigation system consists of two external electromagnets (to be placed on opposite sides of the patient), which guide an ablation catheter (with a small magnet at the tip of the catheter) to the target area in the heart. The accuracy of this procedure is higher than that with manual navigation. Personnel can be quickly trained to use remote magnetic navigation, but the procedure itself is time-consuming, particularly for patients with atrial fibrillation. The major advantage is a considerably lower radiation burden to both patient and operator, in some studies more than 50 %, and a corresponding reduction in physical strain on the operator. The incidence of procedure-related complications seems to be lower than that observed with use of manually operated ablation catheters. Work is ongoing to improve magnetic ablation catheters and methods that can simplify mapping procedures and improve efficacy of arrhythmia ablation. The basic cost for installing a complete magnetic navigation laboratory may be three times that of a conventional electrophysiological laboratory.

INTERPRETATION

The new magnetic navigation system has proved to be applicable during ablation for a variety of tachyarrhythmias, but is still under development.