Abstract：
BACKGROUND: Pulsed field ablation (PFA) of atrial fibrillation is a new method in clinical practice. Despite a favorable safety profile of PFA in atrial fibrillation ablation, rare cases of renal failure, probably due to hemolysis, have recently been reported.
OBJECTIVE: The aim of this study was to determine the rate of hemolysis and cardiac cell death during in vitro PFA with different electric field intensities.
METHODS: Blood samples from healthy volunteers and mouse HL-1 cardiomyocyte cell lines were subjected to in vitro irreversible electroporation using 216 bipolar pulses, each lasting 2 μs with intervals of 5 μs, repeated 20 times at a frequency of 1 Hz. These pulses varied from 500 V to 1500 V. Cell-free hemoglobin levels were assessed spectrophotometrically, and red blood cell microparticles were evaluated by flow cytometry. Cardiomyocyte death was quantified with propidium iodide.
RESULTS: Pulsed field energy (1000 V/cm, 1250 V/cm, and 1500 V/cm) was associated with a significant increase in cell-free hemoglobin (0.32 ± 0.16 g/L, 2.2 ± 0.96 g/L, and 5.7 ± 0.39 g/L; P < .01) and similar increase in the concentration of red blood cell microparticles. Significant rates of cardiomyocyte death were observed at electric field strengths of 750 V/cm, 1000 V/cm, 1250 V/cm, and 1500 V/cm (26.5% ± 5.9%, 44.3% ± 6.2%, 55.5% ± 6.9%, and 74.5% ± 17.8% of cardiomyocytes; P < .01).
CONCLUSIONS: The most effective induction of cell death in vitro was observed at 1500 V/cm. This intensity was also associated with a significant degree of hemolysis.
OBJECTIVE: The aim of this study was to determine the rate of hemolysis and cardiac cell death during in vitro PFA with different electric field intensities.
METHODS: Blood samples from healthy volunteers and mouse HL-1 cardiomyocyte cell lines were subjected to in vitro irreversible electroporation using 216 bipolar pulses, each lasting 2 μs with intervals of 5 μs, repeated 20 times at a frequency of 1 Hz. These pulses varied from 500 V to 1500 V. Cell-free hemoglobin levels were assessed spectrophotometrically, and red blood cell microparticles were evaluated by flow cytometry. Cardiomyocyte death was quantified with propidium iodide.
RESULTS: Pulsed field energy (1000 V/cm, 1250 V/cm, and 1500 V/cm) was associated with a significant increase in cell-free hemoglobin (0.32 ± 0.16 g/L, 2.2 ± 0.96 g/L, and 5.7 ± 0.39 g/L; P < .01) and similar increase in the concentration of red blood cell microparticles. Significant rates of cardiomyocyte death were observed at electric field strengths of 750 V/cm, 1000 V/cm, 1250 V/cm, and 1500 V/cm (26.5% ± 5.9%, 44.3% ± 6.2%, 55.5% ± 6.9%, and 74.5% ± 17.8% of cardiomyocytes; P < .01).
CONCLUSIONS: The most effective induction of cell death in vitro was observed at 1500 V/cm. This intensity was also associated with a significant degree of hemolysis.
摘要：
背景：心房颤动（AF）的脉冲场消融（PFA）是临床实践中的一种新方法。尽管PFA在房颤消融术中具有良好的安全性,罕见的肾衰竭病例,可能是溶血,最近有报道。
目的：这项研究的目的是确定在不同电场强度的体外PFA过程中溶血和心肌细胞死亡的速率。
方法：使用216个双极脉冲对健康志愿者和小鼠HL-1心肌细胞系的血液样本进行体外不可逆电穿孔（IRE），每个持续2μs，间隔5μs，以1Hz的频率重复20次。这些脉冲在500到1500V之间变化。用分光光度法评估无细胞血红蛋白水平，使用流式细胞术评估红细胞微粒（RBCμ）。使用碘化丙锭定量心肌细胞死亡。
结果：PF能量（1000V/cm，1250V/cm,和1500V/cm）与无细胞血红蛋白显着增加（0.31±0.16g/l，2.33±0.90g/l，和5.7±0.20g/l，p<0.05)，RBCμ浓度的增加相似。在750V/cm的电场强度下观察到显著的心肌细胞死亡率，1000V/cm,1250V/cm和1500V/cm（26.5±5.9％，44.3±6.2%,55.5±6.9％和74.5±17.8％的心肌细胞，p<0.05)。
结论：在1500V/cm下观察到最有效的体外细胞死亡诱导。这种强度也与显著程度的溶血有关。
目的：这项研究的目的是确定在不同电场强度的体外PFA过程中溶血和心肌细胞死亡的速率。
方法：使用216个双极脉冲对健康志愿者和小鼠HL-1心肌细胞系的血液样本进行体外不可逆电穿孔（IRE），每个持续2μs，间隔5μs，以1Hz的频率重复20次。这些脉冲在500到1500V之间变化。用分光光度法评估无细胞血红蛋白水平，使用流式细胞术评估红细胞微粒（RBCμ）。使用碘化丙锭定量心肌细胞死亡。
结果：PF能量（1000V/cm，1250V/cm,和1500V/cm）与无细胞血红蛋白显着增加（0.31±0.16g/l，2.33±0.90g/l，和5.7±0.20g/l，p<0.05)，RBCμ浓度的增加相似。在750V/cm的电场强度下观察到显著的心肌细胞死亡率，1000V/cm,1250V/cm和1500V/cm（26.5±5.9％，44.3±6.2%,55.5±6.9％和74.5±17.8％的心肌细胞，p<0.05)。
结论：在1500V/cm下观察到最有效的体外细胞死亡诱导。这种强度也与显著程度的溶血有关。
