Diagnostic value of electrocardiogram during routine electroencephalogram.

Introduction: A single-lead electrocardiogram (EKG) is routinely recorded with electroencephalogram (EEG). This study investigates the frequency and types of EKG abnormalities during routine EEG.

Methods: All routine EEGs (20-60 min) over one year were retrospectively analyzed. A blinded cardiologist interpreted EKG recordings. An epileptologist evaluated EEGs. Demographic data, underlying comorbidities, and indications for the EEG were extracted.

Results: A total of 433 recordings for 365 patients were included. Mean (±SD) age was 46.8 (±21.3) years and 50.4% were females. EKG abnormalities were detected in 28.5% of patients; sinus tachycardia (11%), premature ventricular contractions (7.9%), atrial fibrillation (Afib) (6.3%), sinus bradycardia (2.2%) and premature atrial contractions (1.1%). Afib was more common in females than males (p = 0.020), confirmed in six out of seven patients and discovered in 17 patients. Age (OR: 1.67, 95%CI: 1.05-2.66, p = 0.031), prior diagnosis of epilepsy (OR: 2.25, 95% CI: 1.22 - 4.14, p = 0.009), history of seizure (OR: 1.97,  95%CI: 1.09-3.54, p = 0.024), abnormal EEG (OR: 2.14, 95%CI: 1.25 - 3.66, p = 0.005) and EEGs evaluating seizures/epilepsy (OR: 4.18, 95% CI: 1.32 - 13.21, p = 0.015) or syncope (OR: 3.21, 95% CI: 1.16 - 8.84, p = 0.024) were independently associated with abnormal EKG.

Conclusion: The frequency of EKG abnormalities captured during routine EEGs was high, with Afib being the most significant. Older age, history of epilepsy or seizure, abnormal EEGs, and EEGs evaluating seizures/epilepsy or syncope were significant predictors. These findings suggest neurologists to become more vigilant to EKG recorded during routine EEG as such findings might have diagnostic and therapeutic implications.