What is the initial management approach for a patient presenting with chest pain?

Algorithmic Approach to Chest Pain

Immediate Actions (First 10 Minutes)

Obtain a 12-lead ECG within 10 minutes of patient contact and measure cardiac troponin immediately to identify life-threatening conditions requiring urgent intervention. 1, 2

Step 1: Vital Signs and Monitoring

• Place patient on continuous cardiac monitoring with defibrillator readily available 1
• Assess vital signs including blood pressure in both arms (to detect aortic dissection) 2
• Monitor for hemodynamic instability, which mandates immediate escalation 2

Step 2: ECG Interpretation and Risk Stratification

If ST-segment elevation ≥1 mm in contiguous leads or new left bundle branch block:

• Diagnose STEMI and activate immediate reperfusion pathway 2
• Administer aspirin 160-325 mg (chewable preferred) 1, 2
• Give sublingual nitroglycerin if systolic BP >90 mmHg and HR 50-100 bpm 2
• Administer morphine IV titrated to pain severity 2
• Transport by EMS for primary PCI (door-to-balloon <90 minutes) or thrombolysis (door-to-needle <30 minutes) 2

If ECG shows new ischemic changes (ST depression, T-wave inversions, Q waves) but no ST elevation:

• Diagnose high-risk ACS (NSTEMI/unstable angina likely) 1, 2
• Administer aspirin 160-325 mg immediately 1
• Give nitroglycerin if hemodynamically stable 2
• Arrange urgent hospital transfer by EMS 1
• Serial troponins will differentiate NSTEMI from unstable angina 1

If initial ECG is nondiagnostic but clinical suspicion remains:

• Perform serial ECGs every 15-30 minutes 1
• Consider supplemental leads V7-V9 to detect posterior MI 1
• Proceed to clinical risk stratification below 1

Step 3: Clinical Risk Stratification for Nondiagnostic ECG

High-Risk Features (immediate ED transfer by EMS): 1, 2

• Retrosternal pressure/heaviness building over minutes with radiation to left arm, jaw, or neck
• Associated diaphoresis, dyspnea, nausea, or syncope
• Pain at rest or with minimal exertion
• Age >75 years with any chest discomfort
• Diabetes, renal insufficiency, or known coronary disease
• Women with atypical symptoms (isolated dyspnea, nausea, fatigue)
• Elevated troponin on initial testing

Moderate-Risk Features (ED evaluation required): 1, 2

• Typical anginal symptoms with exertion that resolve with rest
• Multiple cardiac risk factors (age, hypertension, hyperlipidemia, smoking, family history)
• Pain characteristics somewhat consistent with ACS but atypical features present

Low-Risk Features (consider alternative diagnoses): 1, 3

• Sharp, pleuritic pain worsened by breathing or position changes
• Pain localized to very small area (<2 cm diameter)
• Pain reproducible with chest wall palpation
• Fleeting pain lasting only seconds
• Pain radiating below umbilicus
• Burning retrosternal pain related to meals, relieved by antacids

Step 4: Evaluate for Other Life-Threatening Causes

Aortic Dissection: 2, 3

• Sudden-onset "tearing" or "ripping" pain radiating to back
• Pulse or blood pressure differentials between extremities
• New aortic regurgitation murmur
• Obtain chest X-ray and CT angiography if suspected

Pulmonary Embolism: 2, 3

• Acute dyspnea with pleuritic chest pain
• Tachycardia (present in >90%) and tachypnea
• Risk factors: recent surgery, immobilization, malignancy, pregnancy
• Obtain D-dimer if low-risk, CT pulmonary angiography if moderate-to-high risk

Tension Pneumothorax: 3

• Severe dyspnea with unilateral absence of breath sounds
• Tracheal deviation and jugular venous distension
• Requires immediate needle decompression

Pericarditis: 3

• Sharp, pleuritic pain worsened when supine, improved leaning forward
• Friction rub on examination
• Diffuse ST elevation and PR depression on ECG

Step 5: Consider Common Benign Causes (After Excluding Life-Threatening Conditions)

Musculoskeletal (Costochondritis): 3

• Tenderness of costochondral joints on palpation
• Pain reproducible with chest wall pressure
• Pain affected by movement, breathing, or position

Gastroesophageal Reflux Disease: 3

• Burning retrosternal pain related to meals
• Relieved by antacids
• No cardiac risk factors or concerning features

Critical Pitfalls to Avoid

• Never use nitroglycerin response as a diagnostic criterion—esophageal spasm and other conditions also respond to nitroglycerin 1, 2
• Do not delay ED transfer for troponin testing in office settings when ACS is suspected 2
• Never dismiss chest pain based on young age—ACS can occur even in adolescents 2
• Do not assume sharp, pleuritic pain excludes ACS—pericarditis and atypical presentations occur 2
• Women and elderly patients frequently present with atypical symptoms (isolated dyspnea, nausea, syncope, delirium)—maintain high suspicion 1, 2
• Physical examination contributes minimally to diagnosing MI unless shock is present 4, 2

Disposition Algorithm

Route 1 (Immediate EMS transfer): 5

• ST elevation or new LBBB on ECG
• High-risk features with clinical evidence of ACS
• Hemodynamic instability or life-threatening alternative diagnosis

Route 2 (Urgent ED evaluation): 5

• Nondiagnostic ECG with moderate-to-high probability of ACS
• Elevated troponin
• Concerning alternative diagnoses requiring imaging

Route 3 (Outpatient workup possible): 5, 6

• Low probability of ACS with normal ECG and troponin
• Consider stress testing, coronary CT angiography, or cardiac MRI
• Treat alternative diagnoses (GERD, costochondritis, anxiety)

Route 4 (Discharge home): 5

• No suspicion of ACS or other serious pathology
• Clear benign alternative diagnosis identified
• Appropriate follow-up arranged

This systematic approach achieves high diagnostic accuracy while optimizing resource utilization and minimizing mortality through early identification of life-threatening conditions. 5