Respiratory motion influence on catheter contact force during radio frequency ablation procedures

Abstract

Abstract. Minimally invasive catheter ablation is a common treatment option for atrial fibrillation. A common treatment strategy is pulmonary vein isolation. In this case, individual ablation points need to be placed around the ostia of the pulmonary veins attached to the left atrium to generate transmural lesions and thereby block electric signals. To achieve a durable transmural lesion, the tip of the catheter has to be stable with a sufficient tissue contact during radio-frequency ablation. Besides the steerable interface operated by the physician, the movement of the catheter is also influenced by the heart and breathing motion -particularly during ablation. In this paper we investigate the influence of breathing motion on different areas of the endocardium during radio frequency ablation. To this end, we analyze the frequency spectrum of the continuous catheter contact force to identify areas with increased breathing motion using a classification method. This approach has been applied to clinical patient data acquired during three pulmonary vein isolation procedures. Initial findings show that motion due to respiration is more pronounced at the roof and around the right pulmonary veins.Keywords: Radiofrequency Ablation, Contact Force, Respiratory Motion, Electrophysiology MOTIVATIONRadio frequency (RF) ablation is a common treatment option for atrial fibrillation (Afib) [1]. Afib is a heart arrhythmia affecting the left atrium. In contrast to the regular sinus rhythm, irregular electric signals circle within the left atrium. For paroxysmal Afib, the isolation of the pulmonary veins, attached to the left atrium, is the main goal [2]. Ablation lesions need to be placed on the endocardium of the left atrium to block the electric signals. These lesions need to be transmural and form a contiguous line to ensure durable signal block [3]. The actual effective ablation energy per lesion may, however, not only depend on the RF generator settings but also on their respective position. There are several motion patterns present during the intervention that affect an ablation site. Besides overall patient motion, cardiac and respiratory motion also effect the position and deformation of the left atrium [4]. During regular breathing a mean movement of the pulmonary veins of about 1.9 cm has been reported [5]. This movement also affects the RF ablation catheter. Klemm et al. investigated the catheter motion due to heart beat and respiration at different positions around the left atrium, with respiration as the major source of relative motion [6]. This study was performed using a 3-D mapping system.Catheter ablations are commonly performed, at least in part, under fluoroscopic guidance. Fluoroscopic images for a cardiac ablation procedure are shown in Figure 1 for a bi-plane X-ray system. Regular X-ray imaging offers low soft-tissue contrast, therefore new approaches using

Ablation of Refractory Papillary Muscle Ventricular Tachycardia Warranting Multiple Adjunctive Ablation Techniques: A Combined Approach for Success

“…10 Because RF catheter contact has a significant impact on lesion formation, cardiac and respiratory motions have important implications on procedural success. 11 The integration of detailed three-dimensional (3D) cardiac models obtained by computerized tomography or magnetic resonance imaging with 3D electroanatomic mapping and, recently, with fluoroscopic imaging enables precise anatomical catheter navigation under both nonfluoroscopic and fluoroscopic guidance. These strategies seek to improve the operator's understanding of the catheter's location by showing it in relation to a detailed 3D model of the cardiac anatomy.…”