Helmsley Electrophysiology Center (I.K., V.Y.R., S.R.D., J.S.K.), Icahn School of Medicine at Mount Sinai, New York, NY.
Cardiovascular Regenerative Medicine (B.J.W., H.W.C.), Icahn School of Medicine at Mount Sinai, New York, NY.
Circ Arrhythm Electrophysiol. 2022 Sep;15(9):e011120. doi: 10.1161/CIRCEP.122.011120. Epub 2022 Sep 8.
Our understanding of catheter-based pulsed field ablation (PFA) of the ventricular myocardium is limited. We conducted a series of exploratory evaluations of ventricular PFA in swine ventricles.
A focal lattice-tip catheter was used to deliver proprietary biphasic monopolar PFA applications to swine ventricles under general anesthesia, with guidance from electroanatomical mapping, fluoroscopy, and intracardiac echocardiography. We conducted experiments to assess the impact of (1) delivery repetition (2×, 3×, or 4×) at each location, (2) epicardial PFA delivery, and (3) confluent areas of shallow healed endocardial scar created by prior PFA (4 weeks earlier) on subsequent endocardial PFA. Additional assessments included PFA optimized for the ventricle, lesion visualization by intracardiac echocardiography imaging, and immunohistochemical insights.
Experiment no. 1: lesions (n=49) were larger with delivery repetition of either 4× or 3× versus 2×: length 17.6±3.9 or 14.2±2.0 versus 12.7±2.0 mm (<0.01, =0.22), width 13.4±1.8 or 10.6±1.3 versus 10.5±1.1 mm (<0.01, =1.00), and depth 6.1±2.1 or 5.1±1.3 versus 4.2±1.0 mm (<0.01, =0.21). Experiment no. 2: epicardial lesions (n=18) were reliably created and comparable to endocardial lesions: length 24.6±9.7 mm (n=5), width 15.6±4.6 mm, and depth 4.5±3.7 mm. Experiment no. 3: PFA (n=16) was able to penetrate to a depth of 4.8 (interquartile range, 4.5-5.4) mm in healthy myocardium versus 5.6 (interquartile range, 3.6-6.6) mm in adjacent healed endocardial scar (=0.79), suggesting that superficial scar does not significantly impair PFA. Finally, we demonstrate, PFA optimized for the ventricle yielded adequate lesion dimensions, can result in myocardial activation, can be visualized by intracardiac echocardiography, and have unique immunohistochemical characteristics.
This in vivo evaluation offers insights into the behavior of endocardial or epicardial PFA delivered using the lattice-tip catheter to normal or scarred porcine ventricular myocardium, thereby setting the stage for future clinical studies.
我们对基于导管的脉冲场消融（PFA）在心室心肌中的理解有限。我们在猪心室中进行了一系列探索性的心室 PFA 评估。
在全身麻醉下，使用网格尖端导管将专有的双相单极 PFA 应用于猪心室，通过电解剖标测、透视和心内超声心动图进行指导。我们进行了实验，以评估以下因素的影响：（1）在每个部位进行 2×、3×或 4×的传递重复，（2）心外膜 PFA 传递，（3）由先前的 PFA（4 周前）产生的浅愈合心内膜疤痕的融合区域对随后的心内膜 PFA 的影响。其他评估包括针对心室优化的 PFA、心内超声心动图成像的可见性以及免疫组织化学见解。
实验 1：在传递重复 4×或 3×时，与 2×相比，病灶（n=49）更大：长度 17.6±3.9 或 14.2±2.0 与 12.7±2.0mm（<0.01，=0.22），宽度 13.4±1.8 或 10.6±1.3 与 10.5±1.1mm（<0.01，=1.00），深度 6.1±2.1 或 5.1±1.3 与 4.2±1.0mm（<0.01，=0.21）。实验 2：可靠地创建了心外膜病灶（n=18），并与心内膜病灶相当：长度 24.6±9.7mm（n=5），宽度 15.6±4.6mm，深度 4.5±3.7mm。实验 3：PFA（n=16）能够穿透至健康心肌 4.8（四分位间距，4.5-5.4）mm 的深度，而在相邻愈合的心内膜疤痕中为 5.6（四分位间距，3.6-6.6）mm（=0.79），表明浅表疤痕不会显著影响 PFA。最后，我们证明，针对心室优化的 PFA 可产生足够的病灶尺寸，可以导致心肌激活，可以通过心内超声心动图进行可视化，并具有独特的免疫组织化学特征。
这项体内评估为使用网格尖端导管向正常或瘢痕猪心室心肌传递心内膜或心外膜 PFA 的行为提供了深入了解，从而为未来的临床研究奠定了基础。
