Radiofrequency Catheter Ablation of Paroxysmal Atrial Fibrillation; Guidance by Intracardiac Echocardiography and Integration with other Imaging Techniques

Atrial fibrillation is the most common arrhythmia, with an increasing prevalence at higher age. Besides symptoms that affect quality of life, there is a significant risk of thromboembolic complications, heart failure and death. Different therapeutic options are proposed. Results of pharmacological treatment are often disappointing. Adverse side effects of antiarrhythmic medication are considerable and pro-arrhythmic effects may occur. Over the recent years, interest in nonpharmacological therapies for atrial fibrillation has increased. Besides the development of techniques focusing on rate-control, such as His bundle ablation, surgical techniques aiming at restoration of sinus rhythm have been developed. In addition, intra-operative application of radiofrequency current has been proposed and several catheter-based techniques have been developed. The observation that ectopic foci originating in the pulmonary veins can initiate atrial fibrillation, has stimulated the development of percutaneous ablation strategies aiming at ablation at the site of the pulmonary veins. Results are promising, but at the cost of long procedure times and serious procedure-related complications. These issues are (in part) related to the fact that the ablation targets, namely the veno-atrial junctions and the pulmonary veins or their ostia, are not easily visualized using fluoroscopy alone. Furthermore, fluoroscopy does not allow identification of anatomical intra-cardiac structures accurately and cannot be used to verify adequate catheter–tissue contact. Accurate catheter positioning is therefore difficult. These problems can partly be overcome by the use of threedimensional electro-anatomic mapping systems and intra-cardiac echocardiography during the ablation procedure; in addition, non-invasive imaging of the pulmonary veins using magnetic resonance techniques or multi-slice computed tomography will allow planning of the ablation strategy prior to the ablation procedure. The aim of this case report is to describe the integrated use of different imaging modalities in the treatment of atrial fibrillation by radiofrequency catheter ablation. We have performed multi-slice computed tomography prior to radiofrequency catheter ablation to obtain information on the number/location of the pulmonary veins, their ostia and eventual anomalies. During the radiofrequency catheter ablation procedure, intra-cardiac echocardiography was used to determine catheter position in relation to the anatomic structures, assessment of catheter–tissue contact and evaluation of potential complications. A nonfluoroscopic mapping and navigation system provided electrophysiologic information, during the procedure and constructed a three-dimensional model in which ablation lesions could be marked.