Abstract：
BACKGROUND: The efficacy of pulsed field ablation (PFA) for redo procedures is unknown.
OBJECTIVE: In this study, the authors aimed to evaluate the effectiveness of PFA when performing PFA over chronic RFA (redo environment).
METHODS: This was a 3-step in vivo study. In step 1 (creation of redo environment), 6 swine underwent radiofrequency ablation (RFA) with a local impedance measuring catheter and a contact force-enabled catheter in 3 different sites: the right atrium (RA) (intercaval line with intentional gaps), the left atrium (LA) (pulmonary vein isolation [PVI] with intentional gaps and superficial posterior wall ablations), and the left ventricle (LV) (short RFA applications [chronic RFA]). In step 2 (re-ablation), following a survival period of ≈5 weeks, animals were retreated as follows: in the RA, a focal PFA catheter over the prior intercaval line; in the LA, PVI using a pentaspline PFA catheter; and in the LV, animals were randomized to focal PFA or RFA. In each arm, 2 types of lesions were performed: acute or acute over chronic. In step 3 (remapping and euthanization), following an additional 3 to 5 days, all animals were remapped and sacrificed.
RESULTS: In the RA, re-ablation with PFA resulted in a complete intercaval block in all animals, expanding and homogenizing the disparate chronic RFA lesions from a width of 4 to 7 mm (chronic RFA) to a width of 16 to 28 mm (PFA over chronic RFA). In the LA, re-ablation with PFA resulted in complete PVI and transmural ablation of the PW. In the LV, the mean depth for acute RFA (post 2-5 days survival) was 7.6 ± 1.3 mm vs 3.9 ± 1.6 mm in the acute over chronic RFA lesions (P < 0.01). In contrast, the mean depth for acute PFA was 7.0 ± 1.6 mm, similar to when ablating with PFA over RFA (7.1 ± 1.3 mm; P = 0.94).
CONCLUSIONS: PFA is highly efficient for ablation following prior RFA, which may be beneficial in patients presenting for redo procedures. In the ventricle, PFA resulted in lesions that are deeper than RFA when ablating over chronic superficial RFA lesions.
OBJECTIVE: In this study, the authors aimed to evaluate the effectiveness of PFA when performing PFA over chronic RFA (redo environment).
METHODS: This was a 3-step in vivo study. In step 1 (creation of redo environment), 6 swine underwent radiofrequency ablation (RFA) with a local impedance measuring catheter and a contact force-enabled catheter in 3 different sites: the right atrium (RA) (intercaval line with intentional gaps), the left atrium (LA) (pulmonary vein isolation [PVI] with intentional gaps and superficial posterior wall ablations), and the left ventricle (LV) (short RFA applications [chronic RFA]). In step 2 (re-ablation), following a survival period of ≈5 weeks, animals were retreated as follows: in the RA, a focal PFA catheter over the prior intercaval line; in the LA, PVI using a pentaspline PFA catheter; and in the LV, animals were randomized to focal PFA or RFA. In each arm, 2 types of lesions were performed: acute or acute over chronic. In step 3 (remapping and euthanization), following an additional 3 to 5 days, all animals were remapped and sacrificed.
RESULTS: In the RA, re-ablation with PFA resulted in a complete intercaval block in all animals, expanding and homogenizing the disparate chronic RFA lesions from a width of 4 to 7 mm (chronic RFA) to a width of 16 to 28 mm (PFA over chronic RFA). In the LA, re-ablation with PFA resulted in complete PVI and transmural ablation of the PW. In the LV, the mean depth for acute RFA (post 2-5 days survival) was 7.6 ± 1.3 mm vs 3.9 ± 1.6 mm in the acute over chronic RFA lesions (P < 0.01). In contrast, the mean depth for acute PFA was 7.0 ± 1.6 mm, similar to when ablating with PFA over RFA (7.1 ± 1.3 mm; P = 0.94).
CONCLUSIONS: PFA is highly efficient for ablation following prior RFA, which may be beneficial in patients presenting for redo procedures. In the ventricle, PFA resulted in lesions that are deeper than RFA when ablating over chronic superficial RFA lesions.
摘要：
背景：脉冲场消融（PFA）用于重做手术的功效未知。
目的：在本研究中，作者旨在评估PFA相对于慢性RFA(重做环境)进行PFA时的有效性.
方法：这是一项3步体内研究。在步骤1（创建重做环境）中，6头猪在3个不同部位接受了射频消融（RFA），使用局部阻抗测量导管和带接触力的导管：右心房（RA）（有故意间隙的腔内线），左心房（LA）（肺静脉隔离[PVI]有故意间隙和浅层后壁消融），和左心室（LV）（短RFA应用[慢性RFA]）。在步骤2（再消融）中，在~5周的生存期后，动物如下进行治疗：在RA中，先前腔内线上方的局灶性PFA导管；在LA中，使用pentasplinePFA导管的PVI；在LV中，将动物随机分配至局灶性PFA或RFA。在每一只手臂上，进行了2种类型的病变：急性或急性慢性。在步骤3（重新映射和安乐死）中，在额外的3到5天之后，所有动物被重新映射并处死。
结果：在RA中，用PFA再次消融导致所有动物完全的腔室间阻滞,将不同的慢性RFA病变从4至7mm的宽度（慢性RFA）扩展和均质化到16至28mm的宽度（PFA超过慢性RFA）。在洛杉矶,用PFA重新消融导致完全PVI和PW的透壁消融。在LV中，急性RFA的平均深度（2-5天生存后）为7.6±1.3mm，而急性超过慢性RFA病变的平均深度为3.9±1.6mm（P<0.01）。相比之下,急性PFA的平均深度为7.0±1.6mm，与使用PFA消融而使用RFA消融时相似(7.1±1.3mm;P=0.94)。
结论：PFA对于先前RFA后的消融非常有效，这对出现重做手术的患者可能是有益的。在心室，在消融慢性浅表RFA病变时，PFA导致的病变比RFA更深。
目的：在本研究中，作者旨在评估PFA相对于慢性RFA(重做环境)进行PFA时的有效性.
方法：这是一项3步体内研究。在步骤1（创建重做环境）中，6头猪在3个不同部位接受了射频消融（RFA），使用局部阻抗测量导管和带接触力的导管：右心房（RA）（有故意间隙的腔内线），左心房（LA）（肺静脉隔离[PVI]有故意间隙和浅层后壁消融），和左心室（LV）（短RFA应用[慢性RFA]）。在步骤2（再消融）中，在~5周的生存期后，动物如下进行治疗：在RA中，先前腔内线上方的局灶性PFA导管；在LA中，使用pentasplinePFA导管的PVI；在LV中，将动物随机分配至局灶性PFA或RFA。在每一只手臂上，进行了2种类型的病变：急性或急性慢性。在步骤3（重新映射和安乐死）中，在额外的3到5天之后，所有动物被重新映射并处死。
结果：在RA中，用PFA再次消融导致所有动物完全的腔室间阻滞,将不同的慢性RFA病变从4至7mm的宽度（慢性RFA）扩展和均质化到16至28mm的宽度（PFA超过慢性RFA）。在洛杉矶,用PFA重新消融导致完全PVI和PW的透壁消融。在LV中，急性RFA的平均深度（2-5天生存后）为7.6±1.3mm，而急性超过慢性RFA病变的平均深度为3.9±1.6mm（P<0.01）。相比之下,急性PFA的平均深度为7.0±1.6mm，与使用PFA消融而使用RFA消融时相似(7.1±1.3mm;P=0.94)。
结论：PFA对于先前RFA后的消融非常有效，这对出现重做手术的患者可能是有益的。在心室，在消融慢性浅表RFA病变时，PFA导致的病变比RFA更深。
