Kakarla Saikiran, Pr UmaShankar, Saravanan Sabari, Namboodiri Narayanan
Department of Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, 695011, India.
Division of In-Vivo Models and Testing, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, 695011, India.
J Interv Card Electrophysiol. 2024 Oct 14. doi: 10.1007/s10840-024-01927-3.
The bipolar radiofrequency ablation(B-RFA) strategy was increasingly used to target deep intramural re-entrant foci responsible for the arrhythmia not ablated by conventional unipolar RFA / sequential unipolar RFA. Lesional characteristics of various bipolar configurations were largely unknown.
To investigate the lesional geometry in relation to various factors to determine the most effective ablation strategy that minimises steam pops and achieves transmurality. To assess the temperatures at the return electrode.
A custom-made validated ex-vivo bipolar ablation model was used to assess lesion formation. The myocardial sample was placed between two ablation catheters in four different orientations. Lesions were created using different power (30 W, 40 W, 50 W) and time settings(30, 40 and 50 s) with different catheter orientations. Data was analysed using binary logistic regression and multiple linear regression.
Among 107 lesions, The volume of the active catheter lesion (266 +/- 137 mm^3) significantly differed from their return electrode counterparts (130 +/- 91.8 mm^3) (p < 0.001), and the temperatures at the return electrode end were lower than at the active electrode (p = 0.004). Higher power and longer duration application led to more frequent steam pops (p < 0.001), while true parallel configuration resulted in fewer steam pops (p < 0.001).
A custom model without ground electrode temperature monitoring is safe and cost-effective. The safest strategy is a true parallel configuration with an inter-electrode distance of at least 15 mm and a power of 30 W to 40 W, which generates lower steam pops and better transmurality.
双极射频消融（B-RFA）策略越来越多地用于针对常规单极射频消融/序贯单极射频消融未能消融的导致心律失常的深层壁内折返灶。各种双极配置的损伤特征在很大程度上尚不清楚。
研究与各种因素相关的损伤几何形状，以确定最有效的消融策略，该策略可将蒸汽泡产生降至最低并实现透壁性。评估返回电极处的温度。
使用定制的经过验证的体外双极消融模型评估损伤形成。将心肌样本以四种不同方向放置在两个消融导管之间。使用不同功率（30W、40W、50W）和时间设置（30、40和50秒）以及不同的导管方向创建损伤。使用二元逻辑回归和多元线性回归分析数据。
在107个损伤中，有源导管损伤的体积（266±137mm³）与其返回电极对应物的体积（130±91.8mm³）有显著差异（p<0.001），并且返回电极末端的温度低于有源电极处的温度（p=0.004）。更高的功率和更长的持续时间应用导致更频繁的蒸汽泡产生（p<0.001），而真正的平行配置导致更少的蒸汽泡产生（p<0.001）。
一个没有接地电极温度监测的定制模型是安全且具有成本效益的。最安全的策略是真正的平行配置，电极间距至少为15mm，功率为30W至40W，这样产生的蒸汽泡更少且透壁性更好。
