Cardiac syncope can present with subtle but deadly ECG findings. When the history and physical exam do not suggest a diagnosis, always think of the following differentials when interpreting the ECG of patients with syncope or new-onset "seizures":
Ischemia (Acute Coronary Syndrome, Cardiomyopathy, etc.)
Dysrhythmias (Tachycardia, Bradycardia, AV-blocks)
WPW/Pre-excitation syndromes
Hypertrophic cardiomyopathy (HOCM)
Brugada pattern
Arrhythmogenic RV cardiomyopathy (ARVD/ARVC)