Exercise stress test reveals ineligibility for subcutaneous implantable cardioverter defibrillator in patients with Brugada syndrome

J Cardiovasc Electrophysiol. 2017 Dec;28(12):1454-1459. doi: 10.1111/jce.13315. Epub 2017 Sep 1.

Abstract

Background: The eligibility of patients with Brugada syndrome (BrS) for implantation of a subcutaneous implantable cardioverter defibrillator (S-ICD) is not well known. This study aimed to clarify the eligibility of BrS patients for S-ICD using electrocardiography (ECG) at rest and during exercise testing. We also analyzed factors associated with ineligibility for S-ICD from standard 12-lead ECG at rest.

Methods: We enrolled 110 consecutive BrS patients who visited Okayama university hospital from December 2015 to December 2016. All patients were assessed for S-ICD eligibility, which required one lead to satisfy the S-ICD screening template. We assessed standard 12-lead ECG parameters in all participants. Of those who passed S-ICD screening, 45 patients were assessed for S-ICD eligibility during treadmill stress test.

Results: Mean age of study patients was 54 ± 13 years and 108 (98%) were men. In total, 89 patients (81%) satisfied S-ICD indications at rest. Existence of complete right bundle branch block (CRBBB) on standard 12-lead ECG was a significant predictor of ineligibility for S-ICD (odds ratio, 5.00; P = 0.03; 95%CI, 1.14-21.98). Of the 45 patients who underwent treadmill stress testing, 11 patients (24%) showed ineligibility for S-ICD during the test.

Conclusion: CRBBB was a predictor of ineligibility for S-ICD in patients with BrS. Sinus tachycardia changes ECG morphology in some patients and stress testing should be considered before S-ICD implantation.

Keywords: Brugada syndrome; exercise stress test; implantable cardioverter defibrillator; inappropriate shock; subcutaneous implantable cardioverter defibrillator.

MeSH terms

  • Adult
  • Aged
  • Brugada Syndrome / diagnostic imaging*
  • Brugada Syndrome / physiopathology*
  • Brugada Syndrome / surgery
  • Defibrillators, Implantable*
  • Electrocardiography / instrumentation
  • Electrocardiography / methods*
  • Eligibility Determination / methods*
  • Exercise Test / methods*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Risk Factors
  • Subcutaneous Tissue / diagnostic imaging