Affiliations: [a] Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan | [b] Cardiovascular Internal Medicine System Sec., JMS Co., Ltd., Tokyo, Japan | [c] R&D Center, Nidec Copal Electronics Corp., Sano, Tochigi, Japan | [d] Cardiology Department, Saitama Medical University, Hidaka, Saitama, Japan
Abstract: BACKGROUND: A new cooling method is proposed for preventing electrode-tissue overheating during cardiac catheter ablation using a vibrating catheter. Previous work has shown that vibration that results from increased flow velocity around the catheter can have a cooling effect on the electrode. OBJECTIVE: Contact force has been shown to be an important factor that affects cooling and lesion formation, because contact force determines the ratio of power delivery between blood and tissue. In this study, the effect of contact force on electrode cooling and tissue heating was investigated during the operation of an electrode cooled by vibration. METHODS: Using PVA-H or myocardium ablation tissue models under conditions of no flow, electrode and tissue temperatures and lesion sizes were measured at various vibrational frequencies and contact force conditions. RESULTS: The experiments showed that the catheter vibration still decreases the electrode temperature over a contact force range of 2–30 gf. The lesion size was increased with increasing contact force at each vibrational frequency. CONCLUSIONS: Increasing contact force can increase lesion size with cooling by vibration remaining effective.
