Hirao Tatsuhiko, Rettmann Maryam E, Schmidt Megan M, Yasin Omar Z, Kowlgi Gurukripa N, Otsuka Naoto, Koya Taro, Newman Laura K, Packer Douglas L, Siontis Konstantinos C
Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN (T.H., M.E.R., O.Z.Y., G.N.K., N.O., T.K., L.K.N., D.L.P., K.C.S.).
Medtronic, Inc, Minneapolis, MN (M.M.S.).
Circ Arrhythm Electrophysiol. 2025 Feb;18(2):e013120. doi: 10.1161/CIRCEP.124.013120. Epub 2025 Jan 24.
Power-controlled radiofrequency ablation with irrigated-tip catheters has been the norm for ventricular ablation for almost 2 decades. New catheter technology has recently integrated more accurate tissue temperature sensing enabling temperature-controlled irrigated ablation. We aimed to investigate the in vivo ablation parameters and lesion formation characteristics in ventricular myocardium using a novel temperature-controlled radiofrequency catheter.
Twenty canines were divided into 3 groups: 4 noninfarcted, acute (phase I); 8 noninfarcted, chronic (phase II); and 8 infarcted, chronic (phase III). Lesions were delivered with a temperature-controlled radiofrequency system utilizing a chemical vapor deposit diamond for efficient thermal diffusivity. In phase I, 17 ablation settings were tested (temperature set points, 50/60/70 °C; ablation duration, 15/30/60/90/120 s; and power limit, 30/50 W). Four and one of these sets of parameters were further tested in phases II and III, respectively. Lesions were assessed by ex vivo contrast-enhanced magnetic resonance imaging and gross pathology 5 weeks after ablation in phases II/III.
Across all phases, 111 ablation lesions were delivered. Ablation with the power limit of 50 W, the temperature set point of 60 °C, and the duration of 60 s produced significantly larger and deeper lesions (mean, 569.2 mm; mean maximal depth, 9.8 mm) compared with 50 W/60 °C/30 s (mean, 340.4 mm; mean maximal depth, 8.3 mm) and 50 W/50 °C/60 s (mean, 227 mm; mean maximal depth, 6.9 mm), with <0.05 for all pairwise comparisons. Ablation of infarcted myocardium in phase III (50 W/60 °C/30 s) resulted in smaller impedance and bipolar electrogram amplitude changes and lesion size compared with ablation in normal myocardium with the same settings. No steam pop, myocardial perforation, or char formation was observed in any of the 111 ablations across all phases.
In vivo radiofrequency ablation in a canine model with a diamond-tip temperature-controlled catheter using a temperature set point of 60 °C and a power limit of 50 W created large lesions without steam pop risk in both normal and infarcted ventricular myocardia.
近20年来，使用灌注式尖端导管进行功率控制的射频消融一直是心室消融的标准方法。最近，新的导管技术集成了更精确的组织温度传感功能，实现了温度控制的灌注式消融。我们旨在使用一种新型的温度控制射频导管，研究心室心肌的体内消融参数和病变形成特征。
将20只犬分为3组：4只非梗死急性组（I期）；8只非梗死慢性组（II期）；8只梗死慢性组（III期）。使用一种具有化学气相沉积金刚石以实现高效热扩散率的温度控制射频系统进行消融。在I期，测试了17种消融设置（温度设定点为50/60/70°C；消融持续时间为15/30/60/90/120秒；功率限制为30/50瓦）。在II期和III期分别进一步测试了其中4组和1组参数。在II/III期消融5周后，通过离体对比增强磁共振成像和大体病理学评估病变。
在所有阶段共进行了111次消融。与50瓦/60°C/30秒（平均340.4毫米；平均最大深度8.3毫米）和50瓦/50°C/60秒（平均227毫米；平均最大深度6.9毫米）相比，功率限制为50瓦、温度设定点为60°C、持续时间为60秒的消融产生的病变明显更大更深（平均569.2毫米；平均最大深度9.8毫米），所有两两比较的P值均<0.05。与相同设置下正常心肌的消融相比，III期梗死心肌的消融（50瓦/60°C/30秒）导致较小的阻抗和双极电图幅度变化以及较小的病变大小。在所有阶段的111次消融中，均未观察到蒸汽爆发现象、心肌穿孔或炭化形成。
在犬模型中，使用金刚石尖端温度控制导管，温度设定点为60°C，功率限制为50瓦进行体内射频消融，在正常和梗死的心室心肌中均可产生大的病变且无蒸汽爆发风险。
