What is the appropriate diagnosis and initial management for an adult patient with no prior medical history presenting with chest pain?

Diagnosis and Initial Management of Chest Pain in Adults

For an adult with no prior medical history presenting with chest pain, obtain a 12-lead ECG within 10 minutes of arrival and measure cardiac troponin immediately to rapidly identify or exclude acute coronary syndrome, which is the most critical life-threatening diagnosis requiring immediate intervention. 1, 2

Immediate Assessment (First 10 Minutes)

Obtain a 12-lead ECG within 10 minutes of patient arrival in any setting where chest pain suggests possible cardiac origin. 1, 2 This is the single most important initial diagnostic step.

• If ST-segment elevation, new ST depression, or new left bundle branch block is present, immediately activate STEMI or NSTE-ACS protocols per established guidelines. 1, 2
• If the initial ECG is nondiagnostic but clinical suspicion remains high, perform serial ECGs, especially when symptoms persist or clinical condition deteriorates. 1, 2
• Consider supplemental leads V7-V9 in patients with intermediate-to-high ACS suspicion and nondiagnostic initial ECG to detect posterior myocardial infarction. 1, 2

Measure cardiac troponin (preferably high-sensitivity troponin T or I) as soon as possible after presentation in all patients with suspected ACS. 1, 2 Do not wait for troponin results to initiate reperfusion therapy if ECG shows STEMI. 1

Critical Differential Diagnoses to Exclude

The history and physical examination must rapidly identify life-threatening conditions:

Acute Coronary Syndrome

• Presentation: Retrosternal pressure-type discomfort building gradually over minutes, radiating to left arm/jaw/neck, associated with diaphoresis, dyspnea, nausea, or syncope. 1, 3
• May occur at rest or with minimal exertion in unstable angina or NSTEMI. 1
• Physical findings: Diaphoresis, tachypnea, tachycardia, hypotension, crackles, S3 gallop, or new mitral regurgitation murmur may be present, though examination can be normal in uncomplicated cases. 1

Aortic Dissection

• Presentation: Sudden-onset "ripping" or "tearing" chest pain radiating to upper or lower back. 1, 3
• Physical findings: Pulse differential between extremities (30% of cases), blood pressure differential, or new aortic regurgitation murmur. 1
• Risk factors: Hypertension, known bicuspid aortic valve, aortic dilation, or connective tissue disorders. 1

Pulmonary Embolism

• Presentation: Acute dyspnea with pleuritic chest pain. 1, 4, 3
• Physical findings: Tachycardia and tachypnea present in >90% of patients. 1, 4

Tension Pneumothorax

• Presentation: Dyspnea and pleuritic pain on inspiration. 1, 4
• Physical findings: Unilateral absence of breath sounds with hyperresonant percussion. 1, 4

Pericarditis

• Presentation: Sharp, pleuritic chest pain that worsens when supine and improves when sitting forward. 1, 4, 3
• Physical findings: Friction rub, fever, and widespread ST-elevation with PR depression on ECG. 1, 4

Laboratory and Imaging Studies

Repeat troponin measurement at 6-12 hours after initial presentation for risk stratification if the first troponin is normal. 1, 2

Obtain a chest radiograph to evaluate for alternative cardiac, pulmonary, and thoracic causes including pneumonia, pneumothorax, widened mediastinum suggesting aortic dissection, or heart failure. 1, 2

Measure hemoglobin to detect anemia as a potential contributor to chest pain. 1, 2

Risk Stratification After Initial Testing

High-risk patients require urgent coronary angiography (ideally within hours, not days) if they have: 1, 2

• Recurrent ischemia (recurrent chest pain or dynamic ST-segment changes, particularly ST-segment depression or transient ST-segment elevation)
• Elevated troponin levels
• Hemodynamic instability (hypotension, pulmonary rales)
• Major arrhythmias (repetitive ventricular tachycardia, ventricular fibrillation)
• Early post-infarction unstable angina
• Diabetes mellitus
• ECG pattern that precludes assessment of ST-segment changes (e.g., bundle branch block, pacemaker rhythm)

Initial Medical Treatment for Non-STEMI ACS

While awaiting further evaluation, initiate the following medications for patients with acute coronary syndrome without persistent ST-segment elevation: 1, 2

• Aspirin 75-150 mg daily (or clopidogrel if aspirin contraindicated due to hypersensitivity or major gastrointestinal intolerance). 1, 2
• Low molecular weight heparin or unfractionated heparin. 1, 2
• Beta-blocker (unless contraindicated; calcium antagonists may be preferred in patients with contraindications to beta-blockers). 1
• Oral or intravenous nitrates for persistent or recurrent chest pain. 1, 2

Critical Pitfalls to Avoid

Do not use nitroglycerin response as a diagnostic criterion. Relief with nitroglycerin is not diagnostic of myocardial ischemia, as esophageal spasm and other noncardiac conditions also respond to nitroglycerin. 1, 3, 5

Do not assume reproducible chest wall tenderness excludes serious pathology. Seven percent of patients with palpable chest wall tenderness have acute coronary syndrome. 4, 3

Do not dismiss atypical presentations in women, elderly patients, or those with diabetes. These populations frequently present with atypical symptoms including sharp or stabbing pain, dyspnea, fatigue, nausea, or syncope without classic chest pressure. 1, 3

In office settings, if ECG is unavailable, refer the patient to the ED immediately. Do not delay transfer for troponin or other diagnostic testing. 1, 2, 3

Transport patients with clinical evidence of ACS or life-threatening causes urgently to the ED by EMS, not by private vehicle. 1, 2, 3

Setting-Specific Considerations

For patients initially evaluated in the office setting with acute chest pain and suspected ACS, delayed transfer to the ED for troponin or other diagnostic testing should be avoided. 1, 2

Positional chest pain (worse with lying down, turning, twisting, or bending) is usually nonischemic and suggests musculoskeletal or pericardial causes. 1, 3

Physical exercise or emotional stress are common triggers of anginal symptoms, while occurrence at rest or with minimal exertion suggests ACS. 1