This work has been funded in part by the Mark Marchlinski Research Fund. F. Squara has received research grants from the Fédération Francaise de Cardiologie, Sorin Group, and Endosense. Other authors: No disclosures.
In Vitro Evaluation of Ice-Cold Saline Irrigation During Catheter Radiofrequency Ablation
Article first published online: 23 JUL 2014
© 2014 Wiley Periodicals, Inc.
Journal of Cardiovascular Electrophysiology
Volume 25, Issue 10, pages 1125–1132, October 2014
How to Cite
SQUARA, F., MAEDA, S., ALDHOON, B., MARGINIERE, J., SANTANGELI, P., CHIK, W. W., MICHELE, J., ZADO, E. and MARCHLINSKI, F. E. (2014), In Vitro Evaluation of Ice-Cold Saline Irrigation During Catheter Radiofrequency Ablation. Journal of Cardiovascular Electrophysiology, 25: 1125–1132. doi: 10.1111/jce.12479
- Issue published online: 10 OCT 2014
- Article first published online: 23 JUL 2014
- Accepted manuscript online: 20 JUN 2014 06:31AM EST
- Manuscript Accepted: 12 JUN 2014
- Manuscript Revised: 8 JUN 2014
- Manuscript Received: 22 MAY 2014
- Mark Marchlinski Research Fund
- catheter ablation;
- contact force;
- irrigated-tip catheter;
- thrombus formation;
In Vitro Evaluation of Ice-Cold Saline Irrigation
Irrigated radiofrequency (RF) catheters allow tissue-electrode interface cooling, decreasing thrombus risk while enabling higher RF power delivery. The impact of irrigation with ice-cold saline (ICS) instead of conventional ambient-temperature saline (ATS) on lesion formation is unknown.
Methods and Results
We performed 120 RF ablations in vitro on porcine left ventricles, using ICS (<5 °C) or ATS (21 °C) irrigation. For ICS irrigation, the irrigation circuit was cooled externally to maintain delivery of cooled saline at the catheter's tip. We applied 20 g of contact force, and delivered 20 W (irrigation 8 or 17 mL/min) or 30 W (irrigation 17 or 30 mL/min) RF power. Temperatures at tissue-electrode interface and 3-mm depth were assessed by fluoroptic probes. Lesion dimensions were assessed. ICS irrigation cooled the tissue-electrode interface better than ATS (53.9 ± 9.6 °C vs. 63 ± 11.4 °C, P < 0.001). Temperatures at 3-mm depth were similar at 30 W using ICS and ATS (104.2 ± 9.3 °C vs. 105.8 ± 7.3 °C, P = 0.5), but were cooler at 20 W using ICS (71.3 ± 11.6 °C vs. 100.2 ± 11.9 °C, P < 0.001). This translated into smaller lesions at 20 W with ICS versus ATS. At 30 W with 17 mL/min flow rate, lesions had the same depth with ICS and ATS (4.9 ± 0.8 mm vs. 5.4 ± 0.7 mm, P = 0.13) but were narrower with ICS (7.7 ± 0.8 mm vs. 9.3 ± 1.2 mm, P = 0.001). At 30 mL/min, lesions had the same dimensions. Steam pop rate was similar using ICS or ATS irrigation.
ICS irrigation more effectively cools tissue-electrode interface than ATS. This may improve RF safety by potentially decreasing thrombus formation, thus facilitating safe ablation at a low saline volume load. However at lower RF power, ICS reduced lesion size compared to ATS.