Miwa N, Nagata Y, Yamaguchi T, Nagase M, Sasaki T, Nozato T, Ashikaga T, Goya M, Hirao K. Effect of diurnal variations in the QRS complex and T waves on the eligibility for subcutaneous implantable cardioverter-defibrillators.
Heart Rhythm 2019;
16:913-920. [PMID:
30616021 DOI:
10.1016/j.hrthm.2019.01.004]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Indexed: 10/27/2022]
Abstract
BACKGROUND
Subcutaneous implantable cardioverter-defibrillators (S-ICDs) are an established therapy for preventing sudden cardiac death. However, a considerable number of patients still undergo inappropriate shocks even after conventional preimplantation electrocardiographic (ECG) screening.
OBJECTIVE
This study aimed to elucidate the additional effect of diurnal variations in the QRS complex and T waves of 24-hour Holter screening on S-ICD eligibility.
METHODS
Patients with transvenous ICDs who did not need pacing were selected for the study. The ECG was recorded by placing the electrodes to simulate the 3 sensing vectors of the S-ICD, with the patient in the standing and supine positions (conventional), during exercise, and during 24-hour Holter screening. We investigated the additional discrimination of diurnal variations in patients ineligible for S-ICDs as well as characteristics of those patients.
RESULTS
Of the 86 patients (82% men; mean age 54±16 years) analyzed by all 3 screenings, 2 (2.3%) and 3 (3.4%) were considered ineligible by conventional and exercise screening, respectively. An additional 21 patients (24.4%) were found ineligible through Holter screening. A multivariate logistic regression analysis demonstrated that Brugada syndrome and an increased QRS duration per millisecond were associated with ineligibility (odds ratio 5.74; 95% confidence interval 1.74-20.2; P = .003 and odds ratio 1.04; 95% confidence interval 1.01-1.07; P = .007, respectively). T-wave oversensing was mostly observed during 0-6 AM, but no significant diurnal variations were observed in the incorrect QRS profiles.
CONCLUSION
The detection of diurnal variations through Holter monitoring in addition to conventional screening is expected to be useful for determining S-ICD eligibility.
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