Search

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.

Background: Catheter ablation has been increasingly applied in children and adolescents with tachyarrhythmias. The aim of this article is to assess the results of ablation therapy of tachycardias in patients below 18 years of age at Haukeland University Hospital., Material and Methods: 141 patients (70 boys and 71 girls, aged 5-17 (13.5 +/- 3.5 ) years with tachyarrhythmias underwent an electrophysiologic study and catheter ablation in the period 1992-2007., Results: Ablation was successfully performed in 138/141 (98%) patients., The procedure was repeated (3 patients twice) until the arrhythmia substrate disappeared in 16 of 138 patients. 81/141 (57%) patients had accessory pathways; 52 (37%) had double atrioventricular nodal pathways, 48 had concealed and 33 patients had overt (classical Wolff-Parkinson-White-syndrome) atrioventricular pathways. 8 (6%) patients had other atrial or ventricular tachyarrhythmias and 4 (3%) had organic heart disease. Use of a 3D mapping system was decisive for success for ablation in patients with complex cardiac diseases. Procedure-related complications were observed in 2/141 (1.4%) patients of whom one had a temporary third degree and one had a permanent first-degree atrioventricular block which did not entail further treatment., Conclusion: Catheter ablation of tachycardia in children and adolescents is a safe treatment method with a high success rate and few complications and should be preferred before drug therapy.

Background: Atrial fibrillation is associated with increased morbidity and twice the mortality compared to individuals without fibrillation. Treatment with antiarrhythmic drugs has limited effect in paroxysmal atrial fibrillation., Material and Method: The group of patients comprised 59 men and 13 women with an average age of 51 +/- 10, the majority of whom had failed several drug regimens; some had undergone repeated DC conversions. A new method based on radiofrequency ablation and isolation of pulmonary veins from the left atrium may offer curative treatment for paroxysmal atrial fibrillation. The basis for this method is that foci in or close to the pulmonary veins initiate or drive atrial fibrillation. These foci may be identified by transseptal access to the left atrium and isolation of the veins from the left atrium using radiofrequency energy., Results: The group of 72 patients underwent 86 procedures. Foci were observed in 65.3%. Isolation of 3.1 +/- 0.9 veins was performed in 71 patients. During a follow up period of 10.3 +/- 5.1 months, 60.9% reported absence of fibrillation and 81.2% reported cure or considerable improvement. Complications included drainage of pericardial effusion in one patient, cerebral embolus with partial visual impairment in one patient, and an asymptomatic pulmonary vein stenosis in one patient., Conclusion: Paroxysmal atrial fibrillation can be treated in selected patients using pulmonary vein isolation with low to moderate risk of complications. Longer follow up is necessary for full evaluation of effect.