Abstract
Introduction: Increasing electrode size allows an increase in radiofrequency lesion depth. The purpose of this study was to examine the roles of added electrode cooling and electrode-tissue interface area in producing deeper lesions. Methods and Results: In 10 dogs, the thigh muscle was exposed and superfused with heparinized blood. An 8-French catheter with 4- or 8-mm tip electrode was positioned against the muscle with a blood flow of 350 mL/min directed around the electrode. Radiofrequency current was delivered using four methods: (1) electrode perpendicular to the muscle, using variable voltage to maintain the electrode-tissue interface temperature at 60°C; (2) same except the surrounding blood was stationary; (3) perpendicular electrode position, maintaining tissue temperature (3.5-mm depth) at 90°C; and (4) electrode parallel to the muscle, maintaining tissue temperature at 90°C. Electrode-tissue interface temperature, tissue temperature (3.5- and 7.0-mm depths), and lesion size were compared between the 4- and 8-mm electrodes in each method. In Methods 1 and 2, the tissue temperatures and lesion depth were greater with the 8-mm electrode. These differences were smaller without blood flow, suggesting the improved convective cooling of the larger electrode resulted in greater power delivered to the tissue at the same electrode-tissue interface temperature. In Method 3 (same tissue current density), the electrode-tissue interface temperature was significantly lower with the 8-mm electrode. With parallel orientation and same tissue temperature at 3.5-mm depth (Method 4), the tissue temperature at 7.0-mm depth and lesion depth were greater with the 8- mm electrode, suggesting increased conductive heating due to larger volume of resistive heating because of the larger electrode-tissue interface area. Conclusion: With a larger electrode, both increased cooling and increased electrode-tissue interface area increase volume of resistive heating and lesion depth.
| Original language | English |
|---|---|
| Pages (from-to) | 47-54 |
| Number of pages | 8 |
| Journal | Journal of Cardiovascular Electrophysiology |
| Volume | 9 |
| Issue number | 1 |
| Publication status | Published - 1998 |
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Keywords
- Catheter ablation
- Electrode cooling
- Electrode size
- Electrode-tissue interface area
- Lesion size
- Radiofrequency
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
- Physiology
Cite this
Why a large tip electrode makes a deeper radiofrequency lesion : Effects of increase in electrode cooling and electrode-tissue interface area. / Otomo, Kenichiro; Yamanashi, William S.; Tondo, Claudio; Antz, Matthias; Bussey, Jonathan; Pitha, Jan V.; Arruda, Mauricio; Nakagawa, Hiroshi; Wittkampf, Fred H M; Lazzara, Ralph; Jackman, Warren M.
In: Journal of Cardiovascular Electrophysiology, Vol. 9, No. 1, 1998, p. 47-54.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Why a large tip electrode makes a deeper radiofrequency lesion
T2 - Effects of increase in electrode cooling and electrode-tissue interface area
AU - Otomo, Kenichiro
AU - Yamanashi, William S.
AU - Tondo, Claudio
AU - Antz, Matthias
AU - Bussey, Jonathan
AU - Pitha, Jan V.
AU - Arruda, Mauricio
AU - Nakagawa, Hiroshi
AU - Wittkampf, Fred H M
AU - Lazzara, Ralph
AU - Jackman, Warren M.
PY - 1998
Y1 - 1998
N2 - Introduction: Increasing electrode size allows an increase in radiofrequency lesion depth. The purpose of this study was to examine the roles of added electrode cooling and electrode-tissue interface area in producing deeper lesions. Methods and Results: In 10 dogs, the thigh muscle was exposed and superfused with heparinized blood. An 8-French catheter with 4- or 8-mm tip electrode was positioned against the muscle with a blood flow of 350 mL/min directed around the electrode. Radiofrequency current was delivered using four methods: (1) electrode perpendicular to the muscle, using variable voltage to maintain the electrode-tissue interface temperature at 60°C; (2) same except the surrounding blood was stationary; (3) perpendicular electrode position, maintaining tissue temperature (3.5-mm depth) at 90°C; and (4) electrode parallel to the muscle, maintaining tissue temperature at 90°C. Electrode-tissue interface temperature, tissue temperature (3.5- and 7.0-mm depths), and lesion size were compared between the 4- and 8-mm electrodes in each method. In Methods 1 and 2, the tissue temperatures and lesion depth were greater with the 8-mm electrode. These differences were smaller without blood flow, suggesting the improved convective cooling of the larger electrode resulted in greater power delivered to the tissue at the same electrode-tissue interface temperature. In Method 3 (same tissue current density), the electrode-tissue interface temperature was significantly lower with the 8-mm electrode. With parallel orientation and same tissue temperature at 3.5-mm depth (Method 4), the tissue temperature at 7.0-mm depth and lesion depth were greater with the 8- mm electrode, suggesting increased conductive heating due to larger volume of resistive heating because of the larger electrode-tissue interface area. Conclusion: With a larger electrode, both increased cooling and increased electrode-tissue interface area increase volume of resistive heating and lesion depth.
AB - Introduction: Increasing electrode size allows an increase in radiofrequency lesion depth. The purpose of this study was to examine the roles of added electrode cooling and electrode-tissue interface area in producing deeper lesions. Methods and Results: In 10 dogs, the thigh muscle was exposed and superfused with heparinized blood. An 8-French catheter with 4- or 8-mm tip electrode was positioned against the muscle with a blood flow of 350 mL/min directed around the electrode. Radiofrequency current was delivered using four methods: (1) electrode perpendicular to the muscle, using variable voltage to maintain the electrode-tissue interface temperature at 60°C; (2) same except the surrounding blood was stationary; (3) perpendicular electrode position, maintaining tissue temperature (3.5-mm depth) at 90°C; and (4) electrode parallel to the muscle, maintaining tissue temperature at 90°C. Electrode-tissue interface temperature, tissue temperature (3.5- and 7.0-mm depths), and lesion size were compared between the 4- and 8-mm electrodes in each method. In Methods 1 and 2, the tissue temperatures and lesion depth were greater with the 8-mm electrode. These differences were smaller without blood flow, suggesting the improved convective cooling of the larger electrode resulted in greater power delivered to the tissue at the same electrode-tissue interface temperature. In Method 3 (same tissue current density), the electrode-tissue interface temperature was significantly lower with the 8-mm electrode. With parallel orientation and same tissue temperature at 3.5-mm depth (Method 4), the tissue temperature at 7.0-mm depth and lesion depth were greater with the 8- mm electrode, suggesting increased conductive heating due to larger volume of resistive heating because of the larger electrode-tissue interface area. Conclusion: With a larger electrode, both increased cooling and increased electrode-tissue interface area increase volume of resistive heating and lesion depth.
KW - Catheter ablation
KW - Electrode cooling
KW - Electrode size
KW - Electrode-tissue interface area
KW - Lesion size
KW - Radiofrequency
UR - http://www.scopus.com/inward/record.url?scp=15444359497&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=15444359497&partnerID=8YFLogxK
M3 - Article
C2 - 9475577
AN - SCOPUS:15444359497
VL - 9
SP - 47
EP - 54
JO - Journal of Cardiovascular Electrophysiology
JF - Journal of Cardiovascular Electrophysiology
SN - 1045-3873
IS - 1
ER -