# Sudden Cardiac Arrest on the Treadmill: Anomalous Left Main Mimicking Spontaneous Coronary Artery Dissection

## TL;DR

A young woman experienced sudden cardiac arrest during exercise due to a rare coronary artery anomaly, not a spontaneous dissection as initially thought.

## Contribution

Highlights the importance of CCTA in diagnosing anomalous coronary artery anatomy in young patients with sudden cardiac events.

## Key findings

- Initial angiography misdiagnosed SCAD, but CCTA identified an anomalous left main coronary artery.
- Anomalous left main coronary artery with an interarterial course is a high-risk condition for sudden cardiac death in young individuals.
- Surgical correction is the definitive treatment for this rare coronary anomaly.

## Abstract

A 28-year-old healthy woman collapsed while running on a treadmill, with no known past medical history or conditions.

Initial angiography suggested left main spontaneous coronary artery dissection (SCAD), but coronary computed tomography angiography (CCTA) revealed an anomalous left main coronary artery arising from the right sinus with an intramural interarterial course. Surgical correction was performed.

This case demonstrates the diagnostic challenges in a young patient presenting with sudden cardiac arrest during exertion, initially presumed to be SCAD; further evaluation with CCTA revealed no evidence of SCAD. The imaging uncovered an anomalous origin of the left main coronary artery from the right coronary sinus with an interarterial and intramural course, which is a high-risk anomaly associated with sudden cardiac death at a young age.

Anomalous courses of the left main coronary artery are rare and associated with sudden cardiac death, particularly in young individuals. CCTA is the gold standard for diagnosis, with surgical intervention being the definitive treatment.