What is the initial evaluation and management of a patient presenting with chest pain?

Initial Evaluation and Management of Chest Pain

Obtain a 12-lead ECG within 10 minutes of patient arrival and measure cardiac troponin as soon as possible—these are the two essential diagnostic tests that drive all subsequent management decisions. 1, 2

Immediate Actions Upon Presentation

ECG Acquisition (Within 10 Minutes)

• Perform and interpret a 12-lead ECG within 10 minutes regardless of setting (office, ED, or prehospital) 1, 2, 3
• If ECG cannot be obtained in an office setting, immediately transfer the patient to the ED via EMS—do not delay for any reason 1, 2
• Compare the ECG with previous tracings if available to detect subtle changes 1

Cardiac Biomarker Testing

• Measure cardiac troponin immediately upon ED arrival—this is the most sensitive test for detecting acute myocardial injury 1, 2
• Do NOT delay transfer from office settings to obtain troponin results; transport first, test in the ED 1, 2, 3, 4

Transfer Considerations

• Transport suspected ACS or life-threatening chest pain via EMS, not private vehicle 1, 2, 3
• EMS provides critical advantages: prehospital ECG acquisition, trained personnel for arrhythmia management and defibrillation, and shorter ED arrival times 1, 2

Clinical Assessment Components

History Taking—Specific Elements to Elicit

• Pain characteristics: nature (pressure, squeezing, sharp, electrical), onset and duration, location and radiation patterns 2
• Precipitating factors: exertion, emotional stress, rest, positional changes 2
• Relieving factors: rest, nitroglycerin (though response is NOT diagnostic) 2, 3
• Associated symptoms: diaphoresis, nausea, dyspnea, syncope, fatigue—particularly important in women and elderly patients 3
• Important caveat: Sharp, stabbing, or pleuritic pain makes ischemic disease less likely but does NOT exclude it 3

Physical Examination—Critical Findings

• Look for signs suggesting ACS: diaphoresis, tachypnea, tachycardia, hypotension, pulmonary crackles, S3 gallop, new mitral regurgitation murmur 2
• Do NOT rely on reproducible chest wall tenderness to exclude serious pathology—7% of patients with palpable tenderness have ACS 3
• Assess for alternative life-threatening causes: unequal pulses (aortic dissection), unilateral breath sounds (pneumothorax), friction rub (pericarditis) 3, 5

Additional Initial Testing

• Obtain chest radiography to evaluate cardiac, pulmonary, and thoracic causes 2, 3

ECG-Directed Management Algorithm

If ST-Elevation or New LBBB Present

• Treat immediately according to STEMI guidelines—activate catheterization lab for emergent reperfusion 1, 2
• Early STEMI recognition dramatically improves outcomes 1

If ST-Depression or T-Wave Inversions Present

• Treat according to NSTE-ACS guidelines 1, 2
• Proceed with serial troponin measurements and risk stratification 6

If Initial ECG is Nondiagnostic or Normal

• Perform serial ECGs, especially if symptoms persist, clinical suspicion remains high, or condition deteriorates 1, 2
• Time repeat ECGs based on symptom recurrence or clinical changes 1
• Consider supplemental leads V7-V9 if posterior MI is suspected in patients with intermediate-to-high ACS suspicion 1, 3
• Critical point: A normal initial ECG does NOT exclude ACS—up to 6% of patients with evolving ACS have normal initial ECGs 1
• Left ventricular hypertrophy, bundle branch blocks, and ventricular pacing may mask ischemic changes 1

Ongoing Monitoring

• Continue serial ECGs until other diagnostic testing rules out ACS 1
• Do NOT base management decisions solely on a single normal or nondiagnostic ECG 1

Life-Threatening Differential Diagnoses to Exclude

Beyond ACS, systematically consider:

• Aortic dissection: unequal pulses, severe tearing pain radiating to back 3, 5
• Pulmonary embolism: dyspnea, tachycardia, risk factors for thromboembolism 3, 5
• Tension pneumothorax: unilateral breath sounds, tracheal deviation, respiratory distress 3, 5
• Pericarditis: positional pain, diffuse ST elevation with PR depression on ECG 3, 5
• Myocarditis: recent viral illness, diffuse ECG changes 1, 3

Critical Pitfalls to Avoid

• Never delay ECG interpretation—this directly delays critical interventions 2
• Never use nitroglycerin response as diagnostic—relief does not confirm or exclude myocardial ischemia 2, 3
• Never delay ED transfer for office-based troponin testing in suspected ACS 2, 3, 4
• Never assume chest wall tenderness excludes cardiac pathology 3
• Never discharge based solely on a single normal ECG without serial testing or troponin results 1

Special Population Considerations

Women

• Emphasize accompanying symptoms more common in women: nausea, fatigue, dyspnea without typical chest pressure 3
• Women are at higher risk for underdiagnosis of ACS 3

Elderly (≥75 years)

• Consider ACS when atypical presentations occur: isolated dyspnea, syncope, acute delirium, unexplained falls 3
• Maintain lower threshold for cardiac workup in this population 3