In young Emergency Department patients with syncope, most of the time, testing is minimal. Generally, the only universal testing is a pregnancy test and/or an electrocardiogram.
We've gotten pretty good at understanding the "life-threatening" causes of syncope in young adults diagnosed by electrocardiography, including:
- Wolff-Parkinson-White Syndrome
- Hypertrophic Obstructive Cardiomyopathy
- Brugada Syndrome
- Congenital Long QT
But there's always more, and Arrhythmogenic Right Ventricular Dysplasia is one of those "more" that seems not to be on everyone's lists. ARVD is a genetically-inherited abnormality in cardiac desmosomes that leads to fibrofatty deposition in the right ventricle. It is currently estimated to result in ~5% of the sudden cardiac deaths in adults under age 65, secondary to sustained monomorphic ventricular tachycardia. The characteristic EKG finding to look out for is, unfortunately, quite subtle – the "epsilon wave". These waves are most prominent in V1-V3, and manifest as sharp upward deflections from baseline at the conclusion of the QRS complex.
Very few Emergency Department presentations mix the high-risk needle-in-the-haystack with the low-risk like young adults with syncope, so it's important to stay alert for these rare ECG findings.
"Impact of new electrocardiographic criteria in arrhythmogenic cardiomyopathy"