QT prolongation in patients with index evaluation for seizure or epilepsy is predictive of all-cause mortality

Published:November 11, 2021DOI:



      Refractory epilepsy confers a considerable lifetime risk of sudden unexplained death (SUDEP). Mechanisms may overlap with sudden cardiac death (SCD), particularly regarding QTc prolongation. Guidelines in the US do not mandate the use of ECG in diagnostic evaluation of seizures or epilepsy.


      We aimed to determine the frequency of ECG use, QT prolongation and whether it predicts mortality in patients with seizures.


      We performed a retrospective cohort study including all patients seen at Mayo Clinic in Rochester, MN from January 1st 2000 to July 31st 2015 with index evaluation for seizure or epilepsy. Patients with an ECG were categorized by presence of a prolonged QT interval with a primary endpoint of all-cause mortality after the 15-year observation period.


      Optimal cut-off QT intervals most predictive of mortality were identified. Median age was 40.0 years. An ECG was obtained in 18,222 (57.4%) patients. After excluding patients with confounding ECG findings, primary prolonged QT intervals were seen in 223 (1.4%) cases, similar to general population. Kaplan-Meier analysis demonstrated a significant increase in mortality (Cox HR 1.90; 95%CI: 1.76, 2.05) for prolonged optimal cut-off QT, maintained after adjustments for age, Charlson Comorbidity Index and sex (HR 1.48; 95%CI: 1.37, 1.59).


      Use of ECG in diagnostic workup of patients with seizures is poor. A prolonged optimal cut-off QTc interval predicts all-cause mortality in patients evaluated for seizure and those diagnosed with epilepsy. We advocate the routine use of a 12-lead ECG at index evaluation in patients with seizure or epilepsy.

      Graphical abstract


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