Abstract 10168: Development of a Novel Shock Wave Catheter Ablation System to Overcome the Limitations of the Present Radiofrequency Catheter Ablation Therapy
Background: Although radio-frequency catheter ablation (RFCA) has been prevailed as the therapeutic modality for tachy-arrhythmias, there are 2 fundamental and unavoidable problems with this therapy utilizing the joule heat as the source of the ablation energy. One is the limited depth of heat propagation with resultant ineffectiveness for the treatment of ventricular tachy-arrhythmias of epicardial origin and the other is the risk of thrombus formation with resultant thromboembolism. As frequently used for lithotripsy therapy, shock wave (SW) can cause tissue damage at any focus without heat generation in our body. In this study, we thus aimed to develop a novel SW catheter ablation system to overcome these limitations of the present RFCA therapy.
Methods and Results: We were able to develop a novel SW ablation catheter system consisting of 14Fr catheter implanted with a SW reflector, 0.6 mm core-diameter low OH content quartz optical fiber and driven by Q-switched Ho:YAG laser (Figure). The preliminary system can generate SW focusing at local site 2.0 mm apart from the catheter tip, where the overpressures ranged 35-45 MPa (Figure). First, we examined the effects of SW exposure focused on the myocardium by epicardial approach in normal domestic pigs (n=3). The SW applications caused tissue damages with visible intramyocardial hemorrhage and histological myocardial disruptions and hemorrhage near the focal zone. Then, we examined whether the focused SW could influence myocardial electrophysiological properties inside the heart in pigs in vivo (n=4). The percutaneous transcatheter applications of focused SW to atrioventricular node inside the heart caused junctional escaped rhythm (n=3) and AV conduction delay (n=2).
Conclusions: This is the first report showing the effectiveness of the focused SW as an energy source of catheter ablation. Our SW catheter ablation system could be a promising option to overcome the limitations of the present RFCA therapy.
- © 2011 by American Heart Association, Inc.