P1157Defibrillation threshold with subcutaneous implantable-cardioverter defibrillator implanted using an intermuscular 2-incision approach. (18th June 2020)

• Record Type: Journal Article
• Authors: Biffi, M; Ziacchi, M; Martignani, C; Lavalle, C; Piro, A; Diemberger, I
• Is Part Of: Europace. Volume 22(2020)Supplement 1
• Publication Date: 2020-06-18
• Subjects: Arrhythmia -- Treatment -- Periodicals; Cardiac pacing -- Periodicals; Catheter ablation -- Periodicals; Heart -- Physiology -- Periodicals; Electrophysiology -- Periodicals; 617.4120645
• DOI: 10.1093/europace/euaa162.145
• Languages: English
• ISSNs: 1099-5129

Abstract

Abstract: Funding Acknowledgements: NO FUNDING OnBehalf: Rhythm Detect Registry Background: Current subcutaneous implantable cardioverter–defibrillators (S-ICD) deliver 80J, and the conversion test is usually conducted by delivering shock energy of 65 J to ensure a safety defibrillation margin of at least 15 J. However, little is known about the real safety margin in real life clinical practice. Purpose: To determine the defibrillation threshold (DFT) with S-ICD and to investigate its association with clinical characteristics. Methods: De novo S-ICD patients were consecutively enrolled and DFT was evaluated using a pre-specified step-up protocol at implantation. Results: 35 patients, BMI 25 ± 4 kg/m2, left ventricular ejection fraction (LVEF) 48 ± 19%, underwent S-ICD implantation. The generator was positioned in an intermuscular pocket and a 2-incision technique was applied in all patients. The mean DFT was 30 ± 10J and the DFT was >30J in 7 (20%) patients. A single patient had a >40J DFT. The time to shock was 11 ± 3 seconds and the shock impedance was 67 ±21 Ohm at the lowest effective energy. The DFT was comparable in patients with LVEF ≤35% (33 ± 15J) versus >35% (29 ± 5J, p = 0.278), and in patients with BMI ≤25 kg/m2 (30 ± 5J) versus >25kg/m2 (31 ± 14J, p = 0.864). Conclusions: We observed low DFT and low shock impedance in patients who received S-ICD with an intermuscular 2-incision approach. The S-ICD defibrillation success rate at ≤30J was 80%, while 97% of patients were defibrillated at ≤ 40J. We found no difference in DFT according to the LVEF or the BMI.