Differential Diagnosis for Chest Pain

Life-Threatening Causes

The American Heart Association and American College of Cardiology emphasize that initial assessment must focus on rapidly identifying immediately life-threatening conditions, with a combination of severe pain, abrupt onset, pulse differential, and widened mediastinum on chest x-ray having a >80% probability of acute aortic dissection 1, 2, 3, 4
Acute Coronary Syndrome (ACS) can occur at rest without exertion, particularly in unstable angina or NSTEMI, and may present with diaphoresis, tachypnea, tachycardia, hypotension, crackles, S3, or mitral regurgitation murmur 2, 3, 4
Acute aortic dissection is characterized by sudden onset of severe "ripping" or "tearing" chest pain, often radiating to upper or lower back, with risk factors including hypertension, known bicuspid aortic valve, aortic dilation, and connective tissue disorders (Marfan syndrome) 2, 3, 4, 5
Pulmonary Embolism (PE) typically presents with tachycardia and dyspnea in >90% of patients, with pain that may occur with inspiration but can also be present at rest 2, 3, 4

The American College of Cardiology recommends considering cardiac causes unrelated to exertion, including pericarditis, myocarditis, stress cardiomyopathy (Takotsubo), and valvular heart disease, with characteristic signs and symptoms such as fever, chest pain, heart failure signs, and S3 gallop 2, 3, 4, 6

Pneumonia is characterized by fever, localized chest pain, friction rub, regional dullness to percussion, and egophony, while pneumothorax presents with dyspnea and pain on inspiration, unilateral absence of breath sounds 3, 4

The American College of Cardiology recommends obtaining an ECG within 10 minutes and cardiac troponin as soon as possible, performing a focused cardiovascular examination, and obtaining a chest radiograph to evaluate cardiac, pulmonary, and thoracic causes 4, 5, 7
Serial ECGs should be performed if initial ECG is nondiagnostic but high clinical suspicion for ACS remains, and supplemental leads V7-V9 should be considered for posterior MI if intermediate-to-high suspicion and nondiagnostic initial ECG 3, 5

The American Heart Association warns against using nitroglycerin relief as a diagnostic criterion for myocardial ischemia, delaying transfer to ED for troponin or diagnostic testing if ACS is suspected, and assuming a normal examination excludes ACS 2, 3, 4, 5