Predicting inappropriate S-ICD® episodes by simple 12-lead surface ECG parameters

Aims: The present study aims at analyzing the role of a preimplantation 12-lead electrocardiogram (ECG) on the prediction of inappropriate S-ICD (R) episodes. Methods: N=116 screened patients (pts) with an S-ICD (R) and a follow-up of at least 6 months were included. A preimplantation 12-lead ECG (50 mm/s, 10 mm/mV) was analyzed with regard to QRS and T-wave amplitude, T wave concordance or discordance and QRS/T wave ratio in all 12 leads. To ensure an exact determination of parameters Datinf (R) Measure software was used. Results were correlated to the occurrence of oversensing of cardiac signals during follow-up. Results: N = 116 pts. (63,8% male, mean age 40,9 +/- 15,5 years) were included (primary prevention in 47.4% of pts). The most frequent cardiac diseases were hypertrophic cardiomyopathy (HCM) in n = 25 (21,6%), electrical heart disease in n = 20 (17,2%), and dilated cardiomyopathy in n = 17 (14,7%). Mean follow-up was 740 +/- 549 days. During follow- up n = 17 (14.7%) pts. experienced n = 27 inappropriate episodes due to T-wave oversensing. Besides HCM (OR 6.16, CI 1.79-21.15, p = 0.004) a discordance of QRS to T-wave in lead I (OR 6.5, CI 1.86-22.67, p = 0.003) was found to be a strong predictor for inappropriate shocks. In multivariate analysis the pts. with a combination of both had an 8.4-fold higher risk of misclassification of intracardiac signals (p = 0.003) with consecutive inappropriate therapy. Conclusion: A discordance of QRS to T-wave in lead I turned out to be a strong predictor for future inappropriate shocks in a typical S-ICD (R) cohort with special impact on HCM pts. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

This study found that a discordance of QRS to T-wave in lead I turned out to be a strong predictor for future inappropriate shocks in a typical S-ICD (R) cohort, with a special impact on patients with hypertrophic cardiomyopathy (HCM).