An Unusual ECG Finding in a Young Cardiac Arrest Patient
Recently, our group published a case report discussing a young cardiac arrest patient that appeared to have Epsilon waves on the ECG.
What’s an Epsilon Wave?
Epsilon waves are characterized as abnormal depolarizations occurring between the end of a QRS complex and the beginning of a T wave. Usually, the epsilon wave is a tiny little notch best seen in the septal leads. Epsilon waves are widely known to be associated with structural abnormalities of the heart, most notably arrhythmogenic right ventricular cardiomyopathies (ARVCs). In ARVC, the normal myocytes become replaced with a fibrofatty infiltrate that affects conduction and makes the heart prone to potential arrhythmia. Emergency Physicians need to be familiar with the Epsilon wave because this abnormality can be associated with sudden cardiac death.
Epsilon wave courtesy of LITFL. https://litfl.com/epsilon-wave-ecg-library/
Develop a Mental Checklist
The ECG is an essential part of the diagnostic workup for patients presenting to the emergency department with syncope or cardiac arrest. The Epsilon wave is one of many ECG findings I am looking for as I evaluate an ECG in the setting of syncope or cardiac arrest. Emergency physicians train their minds to be on the lookout for high-risk features that may provide clues to the underlying etiology and may even help guide treatment. Did this person collapse because they were having a heart attack? Did the patient code because of hyperkalemia? Do they have an abnormal conduction system that makes them prone to arrhythmia? Did they overdose on a sodium channel blocker? Could they have a massive pulmonary embolism? These are all questions emergency physicians think about when interpreting ECGs in the setting of syncope or cardiac arrest. It’s important to develop a mental checklist when evaluating ECGs.
Meet the Resident & Medical Student CoAuthors
When people ask me what I love about my job, I immediately think of the talented residents and students I have the opportunity to work with at USF. These three rock stars deserve recognition! From left to right: Dr. Brian Samuels (PGY 3), Dr. Bryan Hyman (PGY 2), and future Dr. Christian Schuetz (MS4).
“Tell me and I forget. Teach me and I remember. Involve me and I learn.”
About the Author
Dr. Okonkwo is the Assistant Program Director at USF. She attended medical school at Indiana University and completed her emergency medicine residency training at Carolinas Medical Center in Charlotte, North Carolina.