Preoperative Prediction of Shock Impedance for Subcutaneous Implantable Cardioverter Defibrillator Using Chest Computed Tomography

• Published in: Circulation Journal 2024/06/25, Vol.88(7), pp.1147-1154
• Main Authors: Kasagawa, Akira, Nakajima, Ikutaro, Nakayama, Yui, Togashi, Daisuke, Sasaki, Kenichi, Matsuda, Hisao, Harada, Tomoo, Akashi, Yoshihiro J
• Format: Article
• Language: English
• Subjects: Adipose tissue; Adipose Tissue - diagnostic imaging; Adult; Aged; Chest computed tomography; Defibrillation threshold; Defibrillators, Implantable; Electric Impedance; Female; Humans; Male; Middle Aged; Predictive Value of Tests; Shock impedance; Subcutaneous implantable cardioverter-defibrillator; Tomography, X-Ray Computed; Ventricular Fibrillation - diagnostic imaging; Ventricular Fibrillation - physiopathology; Ventricular Fibrillation - therapy
• ISSN: 1346-9843; 1347-4820; 1347-4820
• DOI: 10.1253/circj.CJ-23-0229

Background: High shock impedance is associated with conversion failure among patients with subcutaneous implantable cardioverter defibrillators (S-ICD). Currently, there is no preoperative assessment method for predicting high shock impedance. This study examined the efficacy of chest computed tomography (CT) as a preoperative evaluation tool to assess the shock impedance of S-ICDs.Methods and Results: The amount of adipose tissue adjacent to the device and anteroposterior diameter at the basal heart region were measured preoperatively using chest CT. We examined the correlation between these measurements and shock impedance at the conversion test. We enrolled 43 patients with S-ICDs (mean [±SD] age 54±15 years; body mass index 23±4 kg/m2; PRAETORIAN score 30–270 points; amount of adipose tissue 1,250±716 cm3), who underwent intraoperative conversion tests by inducing ventricular fibrillation, which was terminated with a 65-J shock. A sufficient concordance correlation coefficient was observed between the shock impedance and the amount of adipose tissue (r=0.616, P