What are the immediate steps for an adult with no known medical history experiencing sharp pectoral pain?

Immediate Management of Sharp Pectoral Pain in Adults

Call 9-1-1 immediately and obtain an ECG within 10 minutes to rule out life-threatening cardiac causes, even though sharp pain is less typical for acute coronary syndrome. 1

Life-Threatening Conditions to Exclude First

Acute Coronary Syndrome

• Sharp chest pain does NOT exclude myocardial infarction, particularly in women, elderly patients, and those with diabetes who frequently present with atypical symptoms including sharp or stabbing pain. 1
• Obtain high-sensitivity cardiac troponin immediately and repeat at 3-6 hours if initial value is negative. 1, 2
• Look for associated symptoms that increase cardiac likelihood: diaphoresis, nausea, dyspnea, radiation to arm/jaw/back, or symptoms interrupting normal activity. 1, 3
• A completely normal physical examination does NOT rule out myocardial infarction—the physical exam contributes almost nothing to diagnosing a heart attack unless shock is present. 3

Aortic Dissection

• Sudden onset of sharp, ripping, or tearing chest pain radiating to the back is the hallmark of aortic dissection, particularly in hypertensive patients. 1
• Check blood pressure in both arms (>20 mmHg difference suggests dissection) and assess all peripheral pulses for differentials. 1, 4
• The abruptness of pain onset is the most specific characteristic for dissection. 1
• Critical pitfall: Normal peripheral pulses do NOT exclude aortic dissection, especially Type B dissections. 3

Pulmonary Embolism

• Assess for acute dyspnea, tachycardia >100 bpm, tachypnea, and pleuritic component to the pain. 1, 4
• Sharp, pleuritic chest pain is a common presentation of PE. 1

Most Likely Diagnosis: Acute Pericarditis

If the sharp pain worsens when lying flat and improves when sitting up or leaning forward, this is pathognomonic for acute pericarditis. 1, 4

Diagnostic Features of Pericarditis

• Sharp, pleuritic chest pain that may be improved by sitting up or leaning forward. 1, 4
• Listen for a pericardial friction rub on physical examination. 1
• ECG shows widespread ST-elevation with PR depression (although changes may be transient). 1, 4
• Troponin may be minimally elevated but does not confer worse prognosis in pericarditis. 1

Other Non-Life-Threatening Causes

Musculoskeletal Pain

• Positional chest pain that can be localized to a very limited area is unlikely related to myocardial ischemia. 1
• Costochondritis presents with positional pain but typically worsens with specific movements rather than just lying flat. 4
• Pectoralis minor syndrome causes chest wall and axillary tenderness with pain and paresthesia into the arm. 5, 6, 7
• Pectoralis major muscle injury typically follows trauma or weightlifting with visible ecchymosis, palpable defect, and weakness on resisted shoulder adduction. 8

Gastrointestinal Causes

• Gastroesophageal reflux can cause sharp chest pain that worsens when lying flat due to increased acid reflux. 4
• Associated symptoms include heartburn, regurgitation, relief with antacids, and worsening after meals or at night. 4

Critical Management Pitfalls to Avoid

• Do NOT use nitroglycerin response as a diagnostic criterion—esophageal spasm and other non-cardiac conditions also respond to nitroglycerin. 1, 4
• Do NOT dismiss cardiac causes based on "sharp" pain quality alone—this descriptor is misleading and cardiac disease can present this way. 1
• Do NOT rely on pain severity to determine urgency—severity is a poor predictor of imminent complications like cardiac arrest. 3
• A single troponin measurement is insufficient—serial measurements at least 6 hours apart are required to exclude myocardial injury. 2

Immediate Action Algorithm

1. Activate EMS (9-1-1) immediately rather than self-transport to hospital. 1, 3
2. Obtain 12-lead ECG within 10 minutes to identify STEMI, ST-depression, T-wave inversions, or PR depression. 1, 4, 2
3. Draw high-sensitivity cardiac troponin immediately and place patient on cardiac monitor. 1, 2, 3
4. Administer aspirin 325 mg (chewed) if signs suggest heart attack and no contraindications exist (recent bleeding, known allergy). 1
5. Assess vital signs including blood pressure in both arms, heart rate, oxygen saturation, and respiratory rate. 2, 3
6. Repeat troponin at 3-6 hours if initial value is negative and clinical suspicion remains. 2

Two negative troponin measurements at least 6 hours apart, non-ischemic ECG, and absence of high-risk features are necessary before considering alternative diagnoses. 2