Surface electrocardiogram screening for subcutaneous implantable cardioverter-defibrillators in Japanese patients with and without brugada syndrome

Abstract

Background: Subcutaneous implantable cardioverter-defibrillators (S-ICD) could eliminate lead-associated complications. We assessed the prevalence of S-ICD ineligibility in conventional ICD recipients and compared it in patients with and without Brugada syndrome (BrS). Methods and Results: Consecutive patients with a transvenous ICD without an indication for antibradycardia pacing were assessed. A patient was considered eligible for S-ICD if the ECG satisfied the screening template, both supine and standing, in ≥1 lead. Among 130 patients (103 men, age 57±15 years), a total of 18 (13.8%) patients were ineligible. The BrS group (n=33) had a significantly higher prevalence of S-ICD screening failure as compared with the non-BrS group (P=0.003; 30% vs. 8.2%). In the BrS group, the body mass index (BMI) was significantly lower, and T/QRS amplitude in lead I was significantly higher in those who were ineligible than that in the patients who were eligible. Of the 10 BrS patients failing the screening, 4 became eligible in the right parasternal electrode position. Conclusions: Among current ICD patients, there was a high incidence of patients with BrS who were unsuitable for S-ICD based on the left parasternal screening test. Suitability screening of patients for S-ICDs should be conducted carefully in patients with BrS, particularly if the BMI is low. Right parasternal electrode positioning should also be tested in such BrS patients.