Quick Reference
RxDrug of choiceAspirin 162-325 mg chewed for suspected ACS.
AltAlternativesTicagrelor 180 mg loading dose for ACS; heparin for PE; labetalol for aortic dissection.
⊘AvoidNitrates with recent PDE5 inhibitor use; NSAIDs in ACS; thrombolytics in aortic dissection.
DxTest of choice12-lead ECG within 10 minutes; high-sensitivity troponin; CT angiography for dissection/PE.
ScKey scoreHEART score for risk stratification of chest pain.
→When to referSTEMI, high-risk NSTEMI, type A aortic dissection, massive PE, esophageal rupture.
Use a structured approach to rule out the worst first; low-risk patients can be safely discharged with follow-up.
Undifferentiated chest pain is a common and challenging ED presentation where the clinician must rapidly identify life-threatening causes (ACS, aortic dissection, PE, tension pneumothorax, esophageal rupture) while avoiding unnecessary admissions. A systematic approach using history, ECG, biomarkers, and validated risk scores (HEART, TIMI, PERC, ADD-RS) allows safe and efficient disposition. The key is to apply a 'worst-first' differential, perform simultaneous stabilization and evaluation, and use high-sensitivity troponin protocols to rule out NSTEMI within 1-2 hours. For low-risk patients, early discharge with follow-up is safe; for high-risk patients, immediate consultation and intervention are critical. This page provides a framework for the emergency physician to manage undifferentiated chest pain from arrival to disposition.
Overview and Recommendations
Background
- •Undifferentiated chest pain is one of the most common emergency department (ED) presentations, accounting for approximately 5-10% of all ED visits in the United States, over 7 million encounters annually. The critical challenge is that a small minority of these patients harbor a life-threatening condition (acute coronary syndrome [ACS], pulmonary embolism [PE], aortic dissection, tension pneumothorax, esophageal rupture) where time-to-treatment directly impacts mortality. The paradigm of 'worst-first' differential diagnosis and rapid risk stratification using validated scores (HEART, TIMI, PERC, aortic dissection detection risk score [ADD-RS]) has replaced the older approach of admitting all chest pain for observation.
- •The dangerous differential for chest pain can be organized by mechanism: ischemic (ACS, demand ischemia), aortic (dissection, rupture), pulmonary (PE, pneumothorax, pneumonia), pericardial (pericarditis, tamponade), esophageal (rupture, spasm), and musculoskeletal. The clinician's primary task is to identify the 5-10% of patients with an immediate threat to life or limb using a systematic, time-sensitive approach.
- •Acute coronary syndrome remains the most feared cause, with an estimated 1.1 million ACS events per year in the US. The shift from troponin T/I to high-sensitivity troponin (hs-cTn) assays has enabled rapid rule-out protocols (0/1-hour, 0/2-hour) that can safely discharge up to 60% of patients with suspected NSTEMI within 2 hours, reducing ED length of stay and admissions.
- •Aortic dissection, though rare (incidence 3-4 per 100,000), carries a mortality of 1- per hour in the first 48 hours if untreated. The key to diagnosis is a high index of suspicion based on risk factors (hypertension, connective tissue disorders, bicuspid aortic valve) and the classic presentation of sudden, severe, tearing chest pain radiating to the back.
- •Pulmonary embolism is another high-risk cause, with an annual incidence of 1-2 per 1,000. The PERC rule and Wells criteria help determine who needs D-dimer testing; a negative PERC (no criteria) can safely avoid testing in low-prevalence populations. For those with suspected PE, CT pulmonary angiography (CTPA) is the gold standard.
- •Other important causes include pericarditis (often pleuritic, positional, with PR depression on ECG), myocarditis (often with viral prodrome, elevated troponin, and normal coronaries), and esophageal rupture (Boerhaave syndrome, vomiting followed by chest pain, subcutaneous emphysema, and mediastinal air on imaging).
Evaluation
- •Suspect a life-threatening cause in any patient presenting with chest pain, especially if sudden onset, severe, or associated with hemodynamic instability, syncope, or dyspnea. The initial evaluation must proceed simultaneously with stabilization: obtain a focused history while the patient is on a monitor, oxygen, and IV access.
- •Ask about the quality (sharp, dull, tearing, pleuritic), onset (sudden vs gradual), location (substernal, left-sided, back), radiation (to arm, jaw, back), duration, exacerbating/relieving factors (exertion, position, breathing), and associated symptoms (diaphoresis, nausea, dyspnea, palpitations, syncope). Also ask about risk factors: age >55 for men, >65 for women, smoking, diabetes, hypertension, hyperlipidemia, family history of premature CAD, prior CAD, cocaine use, pregnancy, recent surgery or immobilization (for PE), connective tissue disease (for dissection).
- •Examine for vital signs including bilateral arm blood pressures (difference >20 mmHg suggests dissection), pulse oximetry, and respiratory rate. Look for signs of heart failure (JVD, rales, S3), pericardial rub, murmurs, asymmetrical pulses, chest wall tenderness, subcutaneous emphysema, and unilateral leg swelling (DVT).
- •Order a 12-lead ECG within 10 minutes of arrival (door-to-ECG time target). Look for ST-elevation MI (STEMI) criteria, ST depression, T-wave inversions, left bundle branch block (new or presumably new), PR depression (pericarditis), S1Q3T3 (PE), and signs of LVH or strain.
- •Obtain a chest X-ray (portable if unstable) to evaluate for pneumothorax, widened mediastinum (aortic dissection), pulmonary edema, pneumonia, or free air under diaphragm (esophageal rupture).
- •Draw blood for high-sensitivity troponin (hs-cTn), use a 0/1-hour or 0/2-hour algorithm based on local protocol. For patients with low pre-test probability (HEART score 0-3), a single hs-cTn below the limit of detection at 0 hours can rule out NSTEMI with >99% negative predictive value.
- •For suspected PE, use the Wells criteria or revised Geneva score. If low probability, order a D-dimer (high sensitivity). If D-dimer positive or high probability, order CTPA. In pregnancy, consider V/Q scan if CTPA is contraindicated.
- •For suspected aortic dissection, use the aortic dissection detection risk score (ADD-RS): high-risk conditions (Marfan, family history, known aortic valve disease, prior aortic surgery, recent aortic manipulation), high-risk pain features (abrupt onset, severe intensity, tearing/ripping quality), and high-risk exam findings (pulse deficit, focal neurologic deficit, new murmur of aortic regurgitation, hypotension/shock). If ADD-RS >0, order CT angiography of the chest/abdomen/pelvis.
- •Consider point-of-care ultrasound (POCUS) to assess for pericardial effusion (tamponade), left ventricular function, aortic root dilation, and pneumothorax (lung sliding).
- •For patients with low-risk chest pain (no ischemic ECG changes, normal initial troponin, no high-risk features), use the HEART score (History, ECG, Age, Risk factors, Troponin) to stratify risk. HEART score 0-3: low risk (1- MACE at); 4-6: moderate risk (12-); 7-10: high risk (50-). Low-risk patients may be eligible for early discharge with outpatient follow-up.
- •Also consider other causes: costochondritis (tenderness on palpation), shingles (rash), anxiety/panic attack (hyperventilation, palpitations), and gastroesophageal reflux (heartburn, relieved by antacids).
Management
- •For any patient with suspected ACS, immediately administer aspirin 162-325 mg chewed (non-enteric coated) and nitroglycerin 0.4 mg sublingual every 5 minutes up to 3 doses if pain persists and SBP >100 mmHg. Do not give nitrates if right ventricular infarction suspected (inferior STEMI with hypotension) or if sildenafil/tadalafil use within 24-48 hours.
- •For STEMI (ST elevation in 2 contiguous leads: ≥1 mm in limb leads, ≥2 mm in precordial leads, or new LBBB), activate the catheterization lab immediately. Goal door-to-balloon time <90 minutes. If transfer to PCI-capable center >120 minutes, consider fibrinolysis (tenecteplase weight-based bolus) within 30 minutes of arrival, unless contraindicated.
- •For NSTEMI (positive troponin with ischemic symptoms or ECG changes), start antithrombotic therapy: heparin (unfractionated or low molecular weight) and consider P2Y12 inhibitor (ticagrelor 180 mg loading dose or clopidogrel 600 mg). Use the GRACE score to guide early invasive vs conservative strategy. High-risk features (recurrent ischemia, hemodynamic instability, arrhythmia, GRACE >140) warrant early angiography (<24 hours).
- •For suspected aortic dissection, immediately lower heart rate and blood pressure: start IV beta-blocker (esmolol or labetalol) to target heart rate 60 bpm, then add vasodilator (sodium nitroprusside or nicardipine) to target SBP 100-120 mmHg. Avoid beta-blocker alone if there is aortic regurgitation or heart failure. Definitive management is surgical for type A (ascending) and medical for type B (descending) unless complicated.
- •For suspected PE with hemodynamic instability (massive PE), administer IV unfractionated heparin bolus (80 units/kg) followed by infusion, and consider thrombolysis (alteplase 100 mg over 2 hours) if no contraindications. For submassive PE (RV strain on echo or elevated troponin), anticoagulate with heparin and consider thrombolysis if clinical deterioration.
- •For pericarditis, treat with NSAIDs (ibuprofen 600-800 mg TID or aspirin 650 mg QID) and colchicine 0.6 mg BID (0.3 mg BID if <70 kg) for to reduce recurrence. Avoid anticoagulation if possible due to risk of hemorrhagic pericardial effusion.
- •For pneumothorax (tension or large), perform needle decompression (14-gauge angiocath in 2nd intercostal space midclavicular line) followed by tube thoracostomy (chest tube to water seal).
- •For esophageal rupture (Boerhaave), start broad-spectrum antibiotics (piperacillin-tazobactam or carbapenem), IV fluids, and consult thoracic surgery emergently for repair.
- •For low-risk chest pain (HEART score 0-3, negative serial troponins, no ischemic ECG), consider discharge with outpatient stress testing or coronary CTA within 72 hours. Provide instructions to return if symptoms recur.
- •What NOT to do: Do not give nitrates in suspected right ventricular infarction or with recent PDE5 inhibitor use. Do not give thrombolytics for STEMI if >12 hours from symptom onset (unless ongoing ischemia) or if contraindications (recent surgery, stroke, bleeding). Do not discharge a patient with a HEART score ≥4 without further evaluation. Do not use NSAIDs in suspected ACS (increase mortality).
- •When to refer: Immediately consult cardiology for STEMI, NSTEMI with high-risk features, or unstable arrhythmias. Consult cardiothoracic surgery for type A aortic dissection or esophageal rupture. Consult interventional radiology for massive PE if thrombolysis contraindicated.
- •Discharge criteria: Hemodynamically stable, pain controlled, negative serial troponins (0 and 2-3 hours), no ischemic ECG changes, HEART score ≤3, and appropriate follow-up arranged. For patients with known CAD or multiple risk factors, consider observation unit or admission.
Board Review — High Yield
- •HEART score, Validated risk stratification tool for chest pain: History, ECG, Age, Risk factors, Troponin. Score 0-3: low risk (1- MACE at).
- •Door-to-ECG time, Target ≤10 minutes for all patients with chest pain.
- •High-sensitivity troponin, Allows 0/1-hour rule-out protocol; a single undetectable hs-cTn at 0 hours rules out NSTEMI with >99% NPV in low-risk patients.
- •Aortic dissection detection risk score (ADD-RS), If any one of three categories (high-risk condition, pain, exam) is positive, obtain CT angiography.
- •PERC rule, For suspected PE: if all 8 criteria negative (age >50, HR >100, sat <95%, prior DVT/PE, surgery, hemoptysis, estrogen use, unilateral leg swelling), no further testing needed.
- •Tension pneumothorax, Clinical diagnosis: hypotension, distended neck veins, absent breath sounds, tracheal deviation. Immediate needle decompression.
- •Boerhaave syndrome, Esophageal rupture after vomiting; chest X-ray shows mediastinal air; treat with antibiotics and surgery.
- •Nitroglycerin contraindications, Right ventricular infarction (inferior STEMI with hypotension), recent PDE5 inhibitor use (sildenafil within 24h, tadalafil within 48h).