Acute aortic syndrome (AAS) is a rare but time-dependent emergency, with a linear mortality increase of 2% per hour of diagnostic delay. It is also difficult to diagnose, with a miss rate of 25% and misdiagnosis rates up to 38%. The gold standard for AAS diagnosis is CT imaging. Although CT imaging is readily available in most EDs, it is impractical to CT scan every patient presenting with chest pain for a multitude …