Department of Cardiology, St. Antonius Hospital, Nieuwegein, the Netherlands; Academic Medical Center (AMC), University of Amsterdam, Amsterdam, the Netherlands.
Semmelweis University, Heart and Vascular Center, Budapest, Hungary.
JACC Clin Electrophysiol. 2019 Feb;5(2):186-196. doi: 10.1016/j.jacep.2018.11.003. Epub 2018 Dec 26.
The ASD2 (Acute Extravascular Defibrillation, Pacing, and Electrogram) study evaluated the ability to adequately sense, pace, and defibrillate patients with a novel implantable cardioverter-defibrillator (ICD) lead implanted in the substernal space.
Subcutaneous ICDs are an alternative to a transvenous defibrillator system when transvenous implantation is not possible or desired. An alternative extravascular system placing a lead under the sternum has the potential to reduce defibrillation energy and the ability to deliver pacing therapies.
An investigational lead was inserted into the substernal space via a minimally invasive subxiphoid access, and a cutaneous defibrillation patch or subcutaneous active can emulator was placed on the left mid-axillary line. Pacing thresholds and extracardiac stimulation were evaluated. Up to 2 episodes of ventricular fibrillation were induced to test defibrillation efficacy.
The substernal lead was implanted in 79 patients, with a median implantation time of 12.0 ± 9.0 min. Ventricular pacing was successful in at least 1 vector in 76 of 78 patients (97.4%), and 72 of 78 (92.3%) patients had capture in ≥1 vector with no extracardiac stimulation. A 30-J shock successfully terminated 104 of 128 episodes (81.3%) of ventricular fibrillation in 69 patients. There were 7 adverse events in 6 patients causally (n = 5) or possibly (n = 2) related to the ASD2 procedure.
The ASD2 study demonstrated the ability to pace, sense, and defibrillate using a lead designed specifically for the substernal space.
ASD2（急性血管外除颤、起搏和心电图）研究评估了在胸骨下空间植入新型植入式心脏复律除颤器（ICD）导线的患者进行充分感知、起搏和除颤的能力。
当无法或不希望进行经静脉植入时，皮下 ICD 是经静脉除颤系统的替代方案。将导线置于胸骨下的替代血管外系统有可能降低除颤能量和提供起搏治疗的能力。
通过微创剑突下入路将研究用导线插入胸骨下空间，并将皮肤除颤贴片或皮下有源模拟器放置在左腋中线。评估起搏阈值和心外刺激。诱发性诱发 2 次室颤以测试除颤效果。
79 例患者植入了胸骨下导线，中位植入时间为 12.0±9.0 分钟。78 例患者中有 76 例（97.4%）至少在 1 个向量中成功进行了心室起搏，78 例患者中有 72 例（92.3%）在≥1 个向量中出现了无心外刺激的夺获。69 例患者中的 30-J 电击成功终止了 128 次室颤中的 104 次（81.3%）。6 例患者中的 7 例不良事件（n=5）或可能（n=2）与 ASD2 程序有关。
ASD2 研究表明，使用专门为胸骨下空间设计的导线进行起搏、感知和除颤是可行的。
