To investigate the frequency and types of potential electrocardiogram (EKG) abnormalities captured during electroencephalography (EEG) recordings. 

EKG abnormalities are occasionally captured during EEG recordings, which can either be related to the presenting spell, or they can be incidental drawing attention to underlying undiagnosed cardiac conditions. 

This study was conducted at King Abdullah University Hospital (KAUH)-Northern Jordan. All EEGs (short/regular EEGs or long term monitoring in ICU or epilepsy monitoring unit) read by a single electroencephalographer over one year (2018) were investigated for EKG abnormalities. A cardiologist reviewed all EKG leads. Simple statistics on the frequency and types of these abnormalities were conducted. 

A total of 433 EEGs for 365 patients were included in the study, with a mean age of patients 46.6 ±21.7 years (males 49.6%). Abnormal EKG was found in 71 EEGs (16.4%). Of those, 28 EEGs (40%) had atrial fibrillation (AF) (6.5% of all EEGs); 19 EEGs (27.1%) had premature ventricular contractions (4.4% of all EEGs); 14 EEGs (20%) had sinus tachycardia (3.2% of all EEGs); 4 EEGs (5.7%) had premature atrial contractions (0.9% of all EEGs); 3 EEGs (4.3%) had sinus arrhythmia (0.7% of all EEGs); and 2 EEGs (2.9%) had sinus bradycardia (0.5% of all EEGs). AF was confirmed in 5 out of 7 patients with known history of AF, and discovered in 17 patients not previously known to have the disease (4.66% of all patients).

The frequency of EKG abnormalities captured during EEG recordings is relatively high, atrial fibrillation being the most common, with possible subsequent important implications on the diagnosis and management of the patient.