Undifferentiated chest pain, minute by minute.
Acute chest pain in the ED: 10-minute ECG, the six can't-miss causes, history likelihood ratios, hs-troponin 0/1 h and 0/2 h deltas, HEART and EDACS, disposition by risk, and when to image.
Reviewed October 2026 · verify against current guidelines
Scope — adults with acute chest pain or an equivalent (pressure, tightness or discomfort in the chest, shoulders, arms, neck, back, upper abdomen or jaw). STEMI and NSTE-ACS treatment live in ACS. Score at the bedside with the HEART pathway tool. Test selection is in non-invasive cardiac testing.
Chest pain · 1 of 6
ECG in 10 minutes, then the killers.
First 10 minutes (2021 chest pain; 2025 ACS)
| ECG | Acquire and read a 12-lead within 10 minutes of arrival, in any setting (Class 1). Read it for STEMI first. Review the prehospital tracing: ischemic changes can resolve before arrival (2022 ACC pathway). |
|---|---|
| Repeat | Nondiagnostic first ECG: repeat serially, especially with high suspicion, ongoing symptoms or deterioration (Class 1). In a national registry, 11% of patients finally diagnosed with STEMI had a nondiagnostic first ECG; 72.4% of them showed STEMI within 90 minutes (2025 ACS). |
| Extra leads | Intermediate-to-high suspicion with a nondiagnostic ECG: V7 to V9 are reasonable to rule out posterior MI (2021, Class 2a). Suspected inferior STEMI: add right-sided leads for RV involvement (2025 ACS). |
| Troponin | Draw cTn as soon as possible, preferably high-sensitivity (Class 1, 2025 ACS). With an ECG showing STEMI, do not wait for it. |
| Chest film | Useful to look for other cardiac, pulmonary and thoracic causes (2021). It must not delay primary PCI (2022 ACC pathway). |
Can't-miss causes and their bedside clues (2021 chest pain guideline)
| ACS | Diaphoresis, tachypnea, tachycardia, hypotension, crackles, S3, new MR murmur. The exam is often normal when uncomplicated. |
|---|---|
| Aortic dissection | Sudden ripping pain into the back. Pulse differential in about 30% (type A more than B). Abrupt severe pain plus pulse differential plus wide mediastinum carries more than 80% probability. Syncope in more than 10%; aortic regurgitation in 40% to 75% of type A. Full workup: aortic dissection. |
| Pulmonary embolism | Tachycardia plus dyspnea in more than 90%; pain on inspiration. |
| Pneumothorax, tension | Pneumothorax: dyspnea, pain on inspiration, unilateral absent breath sounds (Table 4). The guideline names tension pneumothorax, with esophageal rupture, among the nonvascular syndromes to identify early (Section 2.1). |
| Tamponade | No specific sign is listed by these guidelines. Suspect it with hypotension and a known or likely effusion: TTE is recommended for suspected life-threatening nonischemic causes, pericardial effusion included (Class 1). |
| Esophageal rupture | Emesis, subcutaneous emphysema, pneumothorax in about 20%, unilateral reduced breath sounds. Chest pain with a painful, tympanic abdomen raises it. |
Off the pathway — hemodynamic instability, significant arrhythmia or overt heart failure removes the patient from any accelerated pathway (2022 ACC pathway). New ischemic ECG changes mean high risk and NSTE-ACS care, not a rule-out protocol. A normal or unchanged ECG helps but does not exclude ACS (2021).
Chest pain · 2 of 6
History shifts the odds, not the decision.
Words matter
Do not call chest pain atypical. Describe it as cardiac, possibly cardiac or noncardiac (2021, Class 1). Women are at risk of underdiagnosis and more often report accompanying symptoms such as nausea and shortness of breath. Over 75, consider ACS with dyspnea, syncope, acute delirium or an unexplained fall (2021, Class 1). Relief with nitroglycerin does not prove ischemia (2021). For how far a likelihood ratio moves you, see likelihood ratios.
Likelihood ratios for ACS in the ED
| Raises | Prior abnormal stress test, LR 3.1. Peripheral arterial disease, LR 2.7. Pain radiating to both arms, LR 2.6 (Fanaroff 2015). Radiation to one or both shoulders or arms, or pain brought on by exertion: LRs 2.3 to 4.7 (Swap 2005). |
|---|---|
| Lowers | Pain that is stabbing, pleuritic, positional or reproduced by palpation: LRs 0.2 to 0.3 (Swap 2005). |
| ECG | ST depression, LR 5.3. Any ischemia, LR 3.6 (Fanaroff 2015). |
| Scores | HEART 7 to 10, LR 13. HEART 0 to 3, LR 0.20. TIMI 0 to 1, LR 0.31 (Fanaroff 2015). |
Bottom line — history, exam and ECG alone neither confirmed nor excluded ACS in the pooled data; scores that include the first troponin carried more information (Fanaroff 2015). No history feature makes testing unnecessary (Swap 2005).
Chest pain · 3 of 6
Troponin: the delta decides.
US practice first (2022 ACC pathway; 2025 ACS)
| Single draw | Rule out on one sample if hs-cTnT is less than 6 ng/L (the US limit of quantitation) or hs-cTnI is below its LoQ or less than 5 ng/L, and only with a nonischemic ECG and symptom onset at least 3 hours before the draw (2022 ACC pathway). Any single-value pathway needs the sample drawn at least 3 hours after onset (2025 ACS). |
|---|---|
| Modified 0/1 h | The ACC pathway's modified ESC 0/1-h algorithm, and its 0/2-h version, use assay-specific thresholds, with the LoQ as the 0-h single-draw cut-off; its figure note allows less than 5 ng/L instead for hs-cTnI. The 0/2-h approach is identical except the change is measured at 2 h, and it has not been validated in randomized trials (Table 2). Use the cut-offs your laboratory has validated for its assay: some US-cleared assays, such as Siemens Atellica, are not in ESC Table S4. |
| High-STEACS | MI is ruled out if the first hs-cTnI is less than 5 ng/L or hs-cTnT is less than 6 ng/L, when more than 3 h from symptom onset; or if the change from the first to the 3-h value is less than 3 ng/L and the value stays below the sex-specific 99th percentile. Validated in a randomized trial; slower to rule out, with fewer ED discharges than 0/1 or 0/2 h (2022 ACC pathway, Table 2). |
| Observe zone | At least one more hs-cTn at 3 to 6 hours, then classify any injury as chronic injury, acute injury, type 1 MI or type 2 MI (2022 ACC pathway). |
| Abnormal | In US EDs the high group is called abnormal, not MI: classify by the Universal Definition before treating as type 1 MI (2022 ACC pathway). |
European: ESC 0/1 h and 0/2 h logic (ESC 2023)
- Rule out at 0 h if hs-cTn is very low and pain began more than 3 hours before the draw; or if 0 h is low and there is no meaningful 1-h (or 2-h) change.
- Rule in if 0 h is high, or the 1-h (or 2-h) change reaches the assay's delta threshold.
- Observe everyone else: repeat hs-cTn at 3 h, with or without echocardiography.
- 0/1 h is the best option and 0/2 h the second-best. Use them only after STEMI and other emergencies are excluded, only in suspected ACS, and only with the assay they were validated for.
- Performance: rule-out NPV above 99% in large cohorts; rule-in PPV about 70% to 75% (ESC 2023). In less selected US populations the rule-in PPV has been 20% to 50%, so the 2022 ACC pathway calls this group abnormal, not MI.
European: assay-specific cut-offs, ng/L (ESC 2023, Table S4), stated as rules
| Elecsys hs-cTnT, 0/1 h | Rule out: 0 h less than 5 (pain more than 3 h), or 0 h less than 12 with 1-h change less than 3. Rule in: 0 h 52 or more, or 1-h change 5 or more. US labs report values below 6 as less than 6, so in the US the single-draw value is 6 (the LoQ), not 5. |
|---|---|
| Elecsys hs-cTnT, 0/2 h | Rule out: 0 h less than 5 (pain more than 3 h), or 0 h less than 14 with 2-h change less than 4. Rule in: 0 h 52 or more, or 2-h change 10 or more. In the US use 6 (the LoQ) in place of 5 for the single draw. |
| Architect hs-cTnI, 0/1 h | Rule out: 0 h less than 4 (pain more than 3 h), or 0 h less than 5 with 1-h change less than 2. Rule in: 0 h 64 or more, or 1-h change 6 or more. |
| Architect hs-cTnI, 0/2 h | Rule out: 0 h less than 4 (pain more than 3 h), or 0 h less than 6 with 2-h change less than 2. Rule in: 0 h 64 or more, or 2-h change 15 or more. |
| Access hs-cTnI, 0/1 h | Rule out: 0 h less than 4 (pain more than 3 h), or 0 h less than 5 with 1-h change less than 4. Rule in: 0 h 50 or more, or 1-h change 15 or more. |
| Access hs-cTnI, 0/2 h | Rule out: 0 h less than 4 (pain more than 3 h), or 0 h less than 5 with 2-h change less than 5. Rule in: 0 h 50 or more, or 2-h change 20 or more. |
| Other assays | Table S4 lists further hs-cTnI platforms; several have no validated 0/2 h values yet. If your assay is not listed, the ESC algorithms do not apply: use your laboratory's validated pathway. |
Reading the delta
| What it is | The absolute change in ng/L between two draws on the same assay. Cut-offs apply regardless of age, sex and kidney function (ESC 2023). |
|---|---|
| Timing | Thresholds are time-specific. Draw within the protocol window and interpret late draws by the actual collection time. 0 h and 1 h are draw times, not result times (ESC 2023; 2022 ACC pathway). |
| Small numbers | At low concentrations use absolute, not percent, change. A change while both values sit below the 99th percentile can still signal ischemia (2022 ACC pathway; 2025 ACS). |
| Flat but high | A stable elevation over serial draws is chronic injury. A late presenter on the down-slope can also look flat: correlate with symptom timing and keep sampling (2022 ACC pathway). |
| Early presenters | Pain under about 3 hours: no single-draw rule-out. Consider a 3-h sample even after a 1-h rule-out. Late rises occur in about 1%, so re-test with recurrent pain or persistent suspicion (ESC 2023). |
| US reporting | The FDA allows reporting only at or above the limit of quantitation. For hs-cTnT that floor is 6 ng/L, so the 2022 ACC pathway uses less than 6 ng/L for hs-cTnT, and less than the LoQ or less than 5 ng/L for hs-cTnI, as single-draw rule-out values, only with a nonischemic ECG and symptom onset at least 3 hours before the draw. |
| Observe zone | Death or MI at 30 days ranged 5% to 22% in this group (2022 ACC pathway). For hs-cTnT, a 3-h value less than 15 ng/L with a 0-to-3 h change less than 4 ng/L has been validated for further decisions (ESC 2023). |
Conventional assays — repeat at 3 to 6 hours; with hs-cTn, repeat at 1 to 2 hours (2025 ACS, Class 1; the 2021 guideline gives 1 to 3 hours). The 2021 guideline also calls a single hs-cTn below the limit of detection reasonable to exclude injury with a normal ECG and pain that began at least 3 hours before arrival (Class 2a).
Chest pain · 4 of 6
Score it, then place the patient.
HEART and EDACS
| HEART | History, ECG, Age, Risk factors, Troponin; 0 to 10 points. In 2440 Dutch ED patients, 6-week MACE was 1.7% for 0 to 3 (36.4% of patients), 16.6% for 4 to 6 and 50.1% for 7 to 10 (Backus 2013). 1.7% exceeds the 1% low-risk bar, hence serial troponin. |
|---|---|
| HEART Pathway | HEART 0 to 3, a nonischemic ECG and troponin below the 99th percentile at 0 and 3 h. After implementation at 3 US sites, 1461 of 4761 patients (30.7%) were low risk, and 0.4% of them had death or MI by 30 days (Mahler 2018). Score it with the HEART pathway tool. |
| EDACS | Positive or negative points for age, sex, known CAD or 3 or more risk factors at age 18 to 50, diaphoresis, radiation of pain, pain worse with inspiration and pain reproduced by palpation. EDACS-ADP is low risk with EDACS less than 16, no new ischemia on ECG and negative troponin at 0 and 2 h (Than 2014; Stopyra 2015). |
| EDACS evidence | Derivation and validation: 42.2% and 51.3% low risk, sensitivity 99.0% and 100% (Than 2014). A single-site US cohort: 66.7% low risk, 1.1% MACE among them, sensitivity 88.2% (Stopyra 2015). The 2022 ACC pathway cites other US validations at 1% or less. Check which version your ED uses. |
| With hs-cTn | Patients ruled out by an hs-cTn pathway with a nonischemic ECG do not routinely need a score; apply HEART or EDACS selectively when the history worries you (2022 ACC pathway). |
Disposition by risk
| Low | 30-day death or MACE less than 1% (2021, Class 1). Discharge without admission or urgent cardiac testing is reasonable (Class 2a): testing within 30 days has not been shown to help. Arrange follow-up within 30 days, ideally 14 (2022 ACC pathway). |
|---|---|
| Intermediate | Repeat hs-cTn at 3 to 6 hours and add HEART or EDACS. TTE for function, wall motion and effusion (2021, Class 1). Observation unit over admission (Class 2a). Discharge without testing is reasonable if the troponin is flat and either recent normal testing (CT or invasive angiogram within 2 years, stress test within 1 year) or an unchanged chronic elevation is present, with HEART 3 or less or EDACS less than 16, and fast follow-up. Otherwise test, usually before discharge. Follow-up within 7 days (2022 ACC pathway). |
| High | Any of: new ischemic ECG changes, troponin-confirmed acute injury, new LVEF less than 40%, new moderate-severe ischemia on stress testing, hemodynamic instability, or a high CDP score. Invasive angiography is recommended (2021, Class 1). Refractory angina or hemodynamic or electrical instability in NSTE-ACS: immediate invasive strategy (2025, Class 1). Other high-risk NSTE-ACS: invasive within 24 hours is reasonable (Class 2a). |
Chest pain · 5 of 6
Image the intermediate patient.
Intermediate risk, ACS not confirmed (2021 chest pain)
| No known CAD | CCTA to exclude plaque and obstructive CAD (Class 1) or stress testing: exercise ECG, stress echo, PET or SPECT MPI, or stress CMR (Class 1). Choose by local expertise and availability. |
|---|---|
| Stenosis 40% to 90% | Proximal or mid vessel on CCTA: FFR-CT can define vessel-specific ischemia and guide revascularization (Class 2a). FFR-CT turnaround time may delay decisions (2021 figure note). |
| Prior stress result | Moderate-severe ischemia within the past year: invasive angiography (Class 1). Mildly abnormal or inconclusive: CCTA is reasonable (Class 2a). |
| Known CAD | Optimize GDMT before more testing (Class 1). Worsening symptoms with significant left main, proximal LAD or multivessel disease, or prior revascularization: invasive angiography (Class 1). Otherwise stress imaging is reasonable (Class 2a); CCTA for known nonobstructive CAD (Class 2a). Extensive plaque degrades CCTA, so stress testing is preferred. |
| Prior CABG | Stress imaging for ischemia or CCTA for graft patency (Class 1); invasive angiography if testing is indeterminate (Class 1). |
ED versus outpatient (2022 ACC pathway)
| In the ED | When available, CCTA is the preferred non-invasive test for possible ACS without known CAD. No plaque or nonobstructive disease (stenosis less than 50%): discharge. Obstructive (50% or more): admit, treat as ACS and plan angiography unless shared decision favors GDMT. |
|---|---|
| Stress instead | Most intermediate-risk ED patients need stress imaging rather than exercise ECG alone, because known CAD, heart failure and comorbidity are common. A nondiagnostic test should lead to a different modality. |
| Outpatient | Ruled-out patients go home without further testing; outpatient testing only in selected cases. In stable type 2 MI or myocardial injury without ongoing symptoms, the CAD evaluation can be deferred to clinic. Use non-invasive cardiac testing to choose the test. |
| After the scan | Nonobstructive CAD or calcium score 100 or more: start a statin from the ED; aspirin may be reasonable if bleeding risk is low. Send incidental CT findings to the primary clinician. |
Chest pain · 6 of 6
Treat the cause you found.
Management pointers
| STEMI or OMI | Reperfusion; no wait for troponin. Patterns, Sgarbossa and pathways: ACS. |
|---|---|
| NSTE-ACS | Aspirin load then daily low dose for ACS without absolute contraindication (2025, Class 1); the guideline load is 162 to 325 mg, chewed when possible. Antithrombotics and invasive timing: ACS and aspirin. |
| Aortic syndrome | CT is the recommended first imaging test (2022 ACC/AHA aortic disease guideline, Class 1); TEE or MRI are reasonable alternatives (Class 2a). The 2021 chest pain guideline specifies CT angiography of chest, abdomen and pelvis (Class 1). Full workup: aortic dissection. |
| Pulmonary embolism | Pretest probability guides testing (Class 1). Stable with high suspicion: CT angiography with a PE protocol (Class 1). Work it up with the PE pathway tool. |
| Pericardial or obstructive | Suspected life-threatening nonischemic cause, including effusion: TTE (2021, Class 1). In arrest, work the reversible causes: adult cardiac arrest. |
| Myopericarditis | TTE for wall motion and effusion (Class 1); CMR with gadolinium to separate it from other causes (Class 1). |
| Type 2 MI or injury | Treat the precipitant, get a TTE, and consider anatomic or functional CAD testing, deferred to clinic if stable. When unsure between type 1 and type 2, manage as type 1 (2022 ACC pathway). |
| Sickle cell disease | Acute chest pain: emergency transfer by EMS to acute care (2021, Class 1), and exclude ACS (Class 1). |
| Recurrent, cardiac and lung clear | Evaluating for gastrointestinal causes is reasonable (2021, Class 2a). |
CDP clinical decision pathwayhs-cTn high-sensitivity cardiac troponinLoQ limit of quantitationMACE major adverse cardiac eventsOMI occlusion myocardial infarctionCCTA coronary CT angiographyFFR-CT CT-derived fractional flow reserveMPI myocardial perfusion imagingGDMT guideline-directed medical therapyEDACS-ADP ED Assessment of Chest pain Score, accelerated diagnostic protocolTTE transthoracic echocardiographyTEE transesophageal echocardiographyCMR cardiac magnetic resonanceNPV negative predictive valuePPV positive predictive valueLR likelihood ratioTIMI Thrombolysis in Myocardial Infarction scoreSTEMI ST-elevation myocardial infarctionNSTE-ACS non-ST-elevation acute coronary syndromePCI percutaneous coronary interventionLVEF left ventricular ejection fractionACS acute coronary syndromeCAD coronary artery diseasePE pulmonary embolismLAD left anterior descending arteryRV right ventricleCABG coronary artery bypass graftingMRI magnetic resonance imagingPET positron emission tomographySPECT single-photon emission CTMR mitral regurgitation
Educational reference only — not medical advice. Troponin cut-offs are assay-specific and summarize ESC 2023 Table S4 in our own words; use your laboratory's validated pathway and local protocol. Verify against the current ACC/AHA and ESC guidelines.
Sources
Verify against current guidelines and local protocol before acting.
- Gulati M, Levy PD, Mukherjee D, et al. 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain. Circulation 2021;144(22):e368-e454. doi:10.1161/CIR.0000000000001029. Also J Am Coll Cardiol 2021;78(22):e187-e285. doi:10.1016/j.jacc.2021.07.053. Recommendations read from the guideline text and the AHA guideline slide set (professional.heart.org).
- Byrne RA, Rossello X, Coughlan JJ, et al. 2023 ESC Guidelines for the management of acute coronary syndromes. Eur Heart J 2023;44(38):3720-3826. doi:10.1093/eurheartj/ehad191. Section 3.3 and Supplementary data, section 3.3.2 and Table S4 (assay-specific cut-offs).
- Rao SV, O'Donoghue ML, Ruel M, et al. 2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes. Circulation 2025;151(13):e771-e862. doi:10.1161/CIR.0000000000001309. Also J Am Coll Cardiol 2025;85(22):2135-2237. Sections 3.1.2, 4.3.1 and 6.1.
- Kontos MC, de Lemos JA, Deitelzweig SB, et al. 2022 ACC Expert Consensus Decision Pathway on the Evaluation and Disposition of Acute Chest Pain in the Emergency Department. J Am Coll Cardiol 2022;80(20):1925-1960. doi:10.1016/j.jacc.2022.08.750.
- Fanaroff AC, Rymer JA, Goldstein SA, Simel DL, Newby LK. Does this patient with chest pain have acute coronary syndrome? The Rational Clinical Examination systematic review. JAMA 2015;314(18):1955-1965. doi:10.1001/jama.2015.12735.
- Swap CJ, Nagurney JT. Value and limitations of chest pain history in the evaluation of patients with suspected acute coronary syndromes. JAMA 2005;294(20):2623-2629. doi:10.1001/jama.294.20.2623.
- Backus BE, Six AJ, Kelder JC, et al. A prospective validation of the HEART score for chest pain patients at the emergency department. Int J Cardiol 2013;168(3):2153-2158. doi:10.1016/j.ijcard.2013.01.255.
- Mahler SA, Lenoir KM, Wells BJ, et al. Safely identifying emergency department patients with acute chest pain for early discharge. Circulation 2018;138(22):2456-2468. doi:10.1161/CIRCULATIONAHA.118.036528.
- Than M, Flaws D, Sanders S, et al. Development and validation of the Emergency Department Assessment of Chest pain Score and 2 h accelerated diagnostic protocol. Emerg Med Australas 2014;26(1):34-44. doi:10.1111/1742-6723.12164.
- Stopyra JP, Miller CD, Hiestand BC, et al. Performance of the EDACS-accelerated diagnostic pathway in a cohort of US patients with acute chest pain. Crit Pathw Cardiol 2015;14(4):134-138. doi:10.1097/HPC.0000000000000059.
- Isselbacher EM, Preventza O, Hamilton Black J, et al. 2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease. Circulation 2022;146(24):e334-e482. doi:10.1161/CIR.0000000000001106. Section 7.2.
- Facts restated in our own words; no society tables, figures or algorithms reproduced. Not affiliated with or endorsed by the AHA, ACC or ESC.