01Approach to the Critical Patient/attcp56

Immediate stabilization

›Life-threatening etiology recognition

›STEMI or dynamic ischemic ECG changes

›Emergent cath lab activation

›Dual antiplatelet therapy immediately

›Aortic dissection features

›BP differential >20 mmHg between arms

›Sudden maximal-at-onset tearing pain radiating to back

›IV access bilateral large bore, type and crossmatch

›Tension pneumothorax

›Absent breath sounds unilateral with JVD and hypotension

›Immediate needle decompression second ICS midclavicular line

›Massive PE with hemodynamic compromise

›RV strain on ECG, tachycardia, hypoxia

›Systemic thrombolytics if no contraindication

›Esophageal rupture (Boerhaave)

›Subcutaneous emphysema, Hamman crunch

›NPO, urgent cardiothoracic surgery consult

›Cardiac tamponade

›Beck triad: hypotension, JVD, muffled heart sounds

›Emergent pericardiocentesis

Monitoring and targets

›Resuscitation bay assignment criteria

›Systolic BP <90 mmHg or MAP <65 mmHg

›Immediate IV fluid resuscitation 500 ml bolus

›Vasopressor initiation if no response

›SpO2 <90% on room air

›Supplemental O2 titrated to SpO2 >94%

02History/hx106

Symptom characterization

›Pain quality

›Pressure, tightness, squeezing, heaviness, burning: more consistent with ACS

›Sensitivity of classic presentation ~50-60% for ACS

›Sharp, stabbing, pleuritic, positional: less likely ischemic

›Point tenderness reproducible with palpation suggests musculoskeletal

›Tearing or ripping, maximal at onset: dissection until proven otherwise

›Associated interscapular radiation increases dissection probability

Onset and timing

›Temporal features

›Sudden onset maximal at onset

›Aortic dissection, aortic rupture, esophageal rupture

›Tension pneumothorax if associated with dyspnea

›Gradual crescendo

›ACS typical pattern

›Worsening over minutes to hours

›Duration >20 minutes continuous

›ACS until proven otherwise

›Fleeting seconds-long episodes

›Low ischemic concern; consider musculoskeletal or anxiety

›Days of constant pain

›Musculoskeletal, pericarditis, pleuritis

Location and radiation

›Radiation patterns

›Substernal radiating to left arm, jaw, or neck

›Classic ACS; present in ~30-40% of MI patients

›Interscapular back radiation

›Aortic dissection (Type A or B)

›Posterior MI (add leads V7-V9)

›Dermatomal unilateral distribution

›Herpes zoster; vesicular rash may follow

›Right upper quadrant or epigastric referral

›Cholecystitis, pancreatitis, inferior MI

›Neck and jaw only without substernal component

›Atypical ACS especially in women and elderly

Associated symptoms

›High-risk associated features

›Diaphoresis

›High specificity for ACS and hemodynamic compromise

›Syncope or presyncope

›PE, dissection, arrhythmia, aortic stenosis

›Dyspnea

›ACS equivalent presentation especially in women, diabetic, and elderly

›Hemoptysis

›PE, malignancy, severe pneumonia

›Dysphagia or odynophagia

›Esophageal origin chest pain, esophageal rupture

›Fever

›Pericarditis, myocarditis, pneumonia, pleuritis, endocarditis

Provoking and relieving factors

›Contextual modifiers

›Exertional onset

›Ischemia, HCM, aortic stenosis

›Pleuritic: worse with inspiration or cough

›PE, pericarditis, pneumonia, pneumothorax

›Positional: worse supine, relieved by leaning forward

›Pericarditis (pathognomonic when classic)

›Postprandial

›GERD, esophageal spasm, peptic ulcer disease

›Response to nitroglycerin

›Non-response does NOT rule out ACS

›Response to GI cocktail does NOT rule out ACS

Important negatives and atypical presentations

›Atypical presentations requiring vigilance

›Women

›More likely to present with dyspnea, nausea, fatigue without classic chest pain

›2021 AHA/ACC guideline discourages use of "atypical" label

›Elderly patients

›Dyspnea, weakness, syncope as ACS equivalents

›Diabetic patients: silent MI, nausea, fatigue

›MI prevalence ranges from ~1% ages 18-44 to ~4% in patients >=80 presenting with nontraumatic chest pain

Medication history

›Relevant contributors and contraindications

›Cocaine, amphetamines

›Coronary vasospasm, ACS, aortic dissection

›Avoid beta-blockers if cocaine-related; use benzodiazepines

›PDE5 inhibitors (sildenafil, vardenafil, tadalafil)

›Absolute contraindication to nitrates

›Sildenafil or vardenafil: contraindicated within 24 hours

›Tadalafil: contraindicated within 48 hours

›5-fluorouracil or capecitabine

›Coronary vasospasm, oncology-related ACS

›NSAIDs or bisphosphonates

›Peptic ulcer disease, esophagitis-related chest pain

›OCP or HRT

›VTE risk factor; consider PE in younger women

Risk factors

›ACS risk factors

›Hypertension, hyperlipidemia, diabetes mellitus

›Each independently increases CAD risk

›Active smoking or prior tobacco use

›Obesity (BMI >30)

›Family history of premature CAD

›First-degree male relative <55 years, female <65 years

›Prior MI, PCI, CABG, or known CAD

›Prior normal stress test <1 year or coronary angiogram <2 years may allow earlier discharge

›PE risk factors

›Recent surgery or prolonged immobilization

›Active malignancy

›Prior VTE or thrombophilia

›OCP or HRT use, long-haul travel

›Dissection risk factors

›Uncontrolled hypertension (most common modifiable risk)

›Connective tissue disorders: Marfan, Ehlers-Danlos, Loeys-Dietz

›Bicuspid aortic valve, prior aortic surgery

›Pregnancy (peripartum risk)

Review of systems

›Targeted systems review

›Cardiovascular: palpitations, prior cardiac history, orthopnea, PND, leg edema

›Pulmonary: cough, hemoptysis, recent travel or immobilization

›GI: heartburn, nausea, vomiting, melena, hematemesis

›MSK: recent trauma, heavy lifting, repetitive strain

›Neurologic: focal deficits suggesting aortic malperfusion

›Dermatologic: vesicular rash for zoster

›Psychiatric: panic symptoms, hyperventilation, paresthesias

03Physical Exam/exam48

Vital signs

›Hemodynamic assessment

›Blood pressure bilateral arms

›Differential >20 mmHg: aortic dissection

›Sensitivity ~30% alone; pain + pulse differential + widened mediastinum >80% probability

›Heart rate

›Tachycardia: PE, ACS with hemodynamic compromise, tamponade

›Bradycardia: vagal response, inferior MI with conduction involvement

›Respiratory rate and SpO2

›Tachypnea + hypoxia >90% sensitive for PE

›Temperature

›Fever supports pericarditis, pneumonia, myocarditis, endocarditis

Cardiovascular exam

›Cardiac auscultation

›New or worsening murmur

›MR murmur: papillary muscle dysfunction in ACS

›AR murmur: Type A dissection with aortic root involvement

›Aortic stenosis murmur: exertional chest pain

›Pericardial friction rub

›Pericarditis (biphasic or triphasic rub)

›S3 gallop

›New heart failure, decompensated ACS

›Muffled heart sounds

›Pericardial effusion, tamponade

Pulmonary exam

›Lung assessment

›Absent breath sounds unilateral

›Pneumothorax, tension pneumothorax, large effusion

04Differential Diagnosis/ddx68

Life-threatening (cannot miss)

›ACS spectrum

›STEMI: ICD-10 I21.x

›ST elevation in contiguous leads or new LBBB

›Emergent PCI target

›NSTEMI: ICD-10 I21.4

›Troponin positive without ST elevation

›Unstable angina: ICD-10 I20.0

›Troponin negative with ischemic ECG changes or high-risk features

›Acute aortic syndrome

›Type A dissection: ICD-10 I71.01

›Ascending aorta involvement, surgical emergency

›Type B dissection: ICD-10 I71.10

›Descending aorta, primarily medical management

›Intramural hematoma and penetrating aortic ulcer

›CT aortography required to distinguish

›Pulmonary embolism: ICD-10 I26.x

›Massive (hemodynamic compromise)

›Thrombolytics or catheter-directed therapy

›Submassive (RV dysfunction, troponin positive)

›Consider thrombolytics vs anticoagulation alone

›Low-risk (hemodynamically stable, normal RV)

›Anticoagulation, outpatient management possible

›Tension pneumothorax: ICD-10 J93.x

›Clinical diagnosis, do not delay for imaging

›Immediate needle decompression then chest tube

›Esophageal rupture (Boerhaave): ICD-10 K22.3

›Preceding forceful vomiting or instrumentation

05Laboratory Tests/lt46

High-sensitivity cardiac troponin

›hs-cTn: primary biomarker for myocardial injury

›Serial measurement 0 and 1-3 hours (hs-cTn protocol)

›0/1h ESC algorithm: 0 hour + 1 hour result

›0/2h algorithm: 0 hour + 2 hour result

›0/3-6h protocol for conventional troponin assays

›Single hs-cTn below limit of detection at >=3 hours after symptom onset

›Reasonable to exclude myocardial injury (Class IIa)

›CK-MB and myoglobin NOT recommended for diagnosis or prognosis

›2021 AHA/ACC Guideline

›Elevated troponin without ACS: type 2 MI or myocardial injury

›Causes: PE, myocarditis, sepsis, demand ischemia, CKD, contusion

D-dimer

›D-dimer for PE exclusion

›High sensitivity ~97%, low specificity ~40%

›Useful only in low to intermediate pretest probability

›Age-adjusted cutoff: patient age x 10 mcg/l in patients >50 years

›Reduces false positive rate and unnecessary CT

›YEARS algorithm D-dimer threshold: 500 mcg/l if no YEARS criteria, 1000 mcg/l if 1 YEARS criteria

›Validated in pregnancy

BNP and NT-proBNP

›Natriuretic peptides

›BNP >100 pg/ml or NT-proBNP >300 pg/ml: acute HF threshold

›Used when acute heart failure mimics or complicates chest pain

›Elevated in PE with RV strain

›Not specific for etiology; interpret with clinical context

Complete blood count and metabolic panel

›Standard baseline labs

06Diagnostic Tests/dt107

Scoring Systems

›HEART score (Validated ED chest pain risk stratification)

›Five components: History, ECG, Age, Risk factors, Troponin

›Score 0-10; each component 0-2 points

›HEART <=3: low risk, 30-day MACE rate <1%

›HEART 4-6: intermediate risk, MACE rate ~12%

›HEART >=7: high risk, MACE rate ~50%

›HEART Pathway combines HEART score with serial troponin

›HEART <=3 + nonischemic ECG + serial troponin <99th percentile: eligible for early discharge

›2022 ACC Expert Consensus Decision Pathway recommends HEART Pathway

›EDACS (Emergency Department Assessment of Chest Pain Score)

›Age, sex, diaphoresis, radiation, and similar features

›EDACS <16 with 2-hour serial troponin: low risk cohort

›Validated with 0/2h hs-cTn protocol

›30-day MACE rate <1% in low-risk group

›ESC 0/1h hs-cTn algorithm

›Rule-out: hs-cTnI or hs-cTnT below limit of detection at 0h AND 1h

›Sensitivity >99% for NSTEMI

›Rule-in: >5 times upper limit of normal OR absolute delta >rule-in threshold at 1h

›Requires lab-specific thresholds

›PERC rule (PE rule-out criteria)

›All 8 criteria negative in low pretest probability: PE excluded without D-dimer

›Age <50, HR <100, SpO2 >94%, no unilateral leg swelling

›No hemoptysis, no prior VTE, no surgery/trauma in 4 weeks, no OCP/HRT

›Wells PE Score

›Score <=1: low probability (D-dimer then CT if positive)

›Score 2-6: moderate probability (D-dimer then CT if positive)

›Score >6: high probability (proceed to CT directly)

›ADD-RS (Aortic Dissection Detection Risk Score)

›High-risk conditions, high-risk pain features, high-risk exam findings

›Score 0: low risk; D-dimer <500 mcg/l can exclude dissection

›Score >=1: CT aortography recommended

ECG

›12-lead ECG interpretation

›ST elevation >=1 mm in contiguous leads

›STEMI: emergent cath lab activation

›Hyperacute T waves

›Early STEMI or acute ischemia before ST elevation develops

›ST depression and T-wave inversions

›NSTEMI or ischemia; Wellens pattern for LAD involvement

›New or presumed new LBBB

›STEMI equivalent in appropriate clinical context (Sgarbossa criteria)

›Diffuse ST elevation with PR depression

›Pericarditis (saddle-shaped, no reciprocal changes except aVR)

›S1Q3T3 pattern with sinus tachycardia

›PE (low sensitivity ~20%)

›Low voltage with electrical alternans

›Pericardial effusion or tamponade

›Posterior MI: ST depression in V1-V4

›Add leads V7-V9 to diagnose; up to 6% of ischemia missed on single ECG

MRI

›Cardiac MRI (CMR)

›Late gadolinium enhancement (LGE)

›Myocarditis: subepicardial or midmyocardial pattern

›MI: subendocardial or transmural distribution in coronary territory

›Pericarditis: pericardial LGE

›Not first-line in acute ED setting

›Used for subacute diagnosis when troponin elevated without clear cause

›Takotsubo: apical ballooning, no significant LGE

›MRI aortography

›Alternative to CT for dissection in patients with contrast allergy or CKD

›High sensitivity and specificity comparable to CT

›Limited by time and availability in emergent setting

CT

›CT pulmonary angiography (CTPA)

›Gold standard for PE diagnosis

›Sensitivity 83-96%, specificity 86-97%

›ACEP Level B recommendation

›Requires adequate renal function and contrast tolerance

›Estimated GFR >30 ml/min/1.73m2 generally required

›Incidental findings common: evaluate all mediastinal structures

›CT aortography

›Gold standard for aortic dissection

›Sensitivity ~95-100%, specificity ~96-100%

›Identifies intimal flap, extent of dissection, branch vessel involvement

›CT angiography from aortic root to iliacs

›Identifies both Type A and Type B dissection

›Coronary CT angiography (CCTA)

›Recommended for intermediate-risk patients with negative or inconclusive ACS workup

›Reduces time to diagnosis by 50% compared to nuclear stress testing

›2021 AHA/ACC Guideline: Class IIa recommendation

›Sensitivity ~97-99% for obstructive CAD, specificity ~79-86%

›High negative predictive value allows safe discharge

›Low-risk patients do NOT benefit from stress testing or cardiac imaging within 30 days

›2021 AHA/ACC Guideline

›Triple rule-out CTA

›Simultaneously evaluates coronary arteries, aorta, pulmonary arteries

›Select intermediate-risk patients where all three diagnoses on differential

›Higher radiation and contrast load; use judiciously

Ultrasound

›Point-of-care ultrasound (POCUS)

›Cardiac POCUS

›Wall motion abnormalities: ACS vs myocarditis

›RV dilation and paradoxical septal motion: PE

›Pericardial effusion and cardiac swinging: tamponade

›Aortic root dilation: Type A dissection screening

›Lung POCUS

›Pneumothorax: absent lung sliding, absent B-lines, lung point sign

›B-lines: pulmonary edema from ACS-related acute HF

›Consolidation with air bronchograms: pneumonia

›IVC assessment

›Collapsible IVC <2 cm: volume responsiveness

›Plethoric IVC >2.5 cm non-collapsing: elevated RA pressure, tamponade, PE

›Abdominal aortic ultrasound

›Aortic root dilation >3.5 cm raises dissection concern

›Abdominal AAA evaluation in older patients with chest-abdominal pain

›Formal echocardiography (TTE)

›Recommended for intermediate-risk patients

›Assess LVEF, wall motion, valvular disease, pericardial effusion

›Class IIa recommendation for undifferentiated chest pain workup

›TEE reserved for suspected aortic dissection in hemodynamically unstable patients

›Sensitivity ~95%, specificity ~77-100% for dissection

07Disposition/dispo37

Discharge criteria

›Low-risk discharge pathway

›HEART score <=3 + nonischemic ECG + serial troponin below 99th percentile

›30-day MACE rate <1%; safe for discharge

›2022 ACC Expert Consensus Decision Pathway

›Single hs-cTn below limit of detection if symptoms onset >=3 hours prior

›Normal ECG required

›No high-risk features on history or exam

›No diaphoresis, hemodynamic instability, or ongoing pain

›Arranged follow-up with PCP or cardiology within 7 days

›Intermediate-risk features discharged after normal testing: close follow-up still recommended

Observation unit

›Intermediate-risk management

›HEART score 4-6 or observation zone on hs-cTn algorithm

›Serial troponin at 3-6 hours

›Consider predischarge CCTA or stress testing

›Predischarge stress testing considerations

›Exercise ECG: appropriate for patients who can exercise with interpretable ECG

›Nuclear or echo stress: for LBBB, paced rhythm, or unable to exercise

›Observation 12-24 hours with serial ECGs and reassessment

Admission criteria

›High-risk admission indications

›STEMI or NSTE-ACS: cardiology admission

›STEMI: cath lab within 90 minutes of first medical contact

›NSTEMI high risk: early invasive strategy within 24 hours

›HEART score >=7 or rising troponin with ischemic ECG changes

›Coronary angiography consideration

›Hemodynamic instability, significant arrhythmia, acute heart failure

08Treatment/t77

Immediate universal interventions

›All undifferentiated chest pain

›IV access, cardiac monitoring, pulse oximetry

›Two large-bore IVs for hemodynamically unstable

›12-lead ECG within 10 minutes

›Class I recommendation

›Supplemental O2 only if SpO2 <90%

›Routine O2 NOT recommended in non-hypoxic ACS patients

›Evidence: AVOID-O2 and DETO2X-AMI trials

›NPO if procedural intervention anticipated

ACS treatment

›Antiplatelet therapy

›Aspirin 162-325 mg (chewed, non-enteric coated)

›Class I recommendation; give as soon as ACS suspected

›2025 ACC/AHA ACS Guideline

›P2Y12 inhibitor (if ACS confirmed or high probability)

›Ticagrelor 180 mg loading dose (preferred in NSTEMI)

›Maintenance: 90 mg twice daily

›Clopidogrel 600 mg loading dose

›Alternative if ticagrelor unavailable or bleeding risk high

›Prasugrel 60 mg loading dose (PCI only, avoid in prior stroke/TIA or age >=75)

›Nitroglycerin for ischemic pain

›NTG 0.4 mg sublingual every 5 minutes x 3 doses

›If SBP >=90 mmHg and no RV infarct

›Contraindicated with recent PDE5 inhibitor use

›IV NTG for persistent pain, hypertension, or pulmonary edema

›Start 5-10 mcg/min, titrate 5-10 mcg/min every 3-5 minutes

›Target symptom relief or SBP reduction; avoid SBP <90 mmHg

›Analgesics

›Morphine 2-4 mg IV or fentanyl 25-50 mcg IV for refractory pain

›Use cautiously: morphine may delay P2Y12 absorption

›Fentanyl preferred if morphine concern

›Anticoagulation

›Unfractionated heparin (UFH)

›STEMI/NSTEMI bolus 60 units/kg IV (max 4000 units)

›Infusion 12 units/kg/hour (max 1000 units/hour)

›Target aPTT 50-70 seconds

›Enoxaparin (LMWH) for NSTEMI

›1 mg/kg subcutaneous every 12 hours

›Reduce to 1 mg/kg once daily if eGFR <30 ml/min/1.73m2

›Avoid anticoagulation until dissection excluded in uncertain cases

›Beta-blocker

›Metoprolol tartrate 5 mg IV every 5 minutes x 3 doses (acute setting)

›Only if HR >60, SBP >120 mmHg, no signs of HF

›Transition to oral metoprolol 25-50 mg twice daily

›Contraindications: cocaine toxicity, severe bronchospasm, high-degree AV block, cardiogenic shock

Pericarditis treatment

›Anti-inflammatory regimen

›Ibuprofen 600 mg three times daily OR ASA 750-1000 mg three times daily

›Continue until pain resolves and CRP normalizes

›Taper NSAID over 2-4 weeks

›Colchicine 0.5 mg twice daily for 3 months (if weight >70 kg)

›0.5 mg once daily if weight <=70 kg

›Reduces recurrence rate from 30% to 15%

›2024 JAMA pericarditis review

›Gastroprotection with PPI during NSAID course

›Especially if prolonged use or concurrent anticoagulation

›Physical activity restriction until asymptomatic and CRP normalized

Pulmonary embolism treatment

›Risk-stratified anticoagulation

›Massive PE with hemodynamic compromise

›Systemic thrombolytics: alteplase 100 mg IV over 2 hours

›Contraindications: recent surgery <10 days, prior hemorrhagic stroke, active bleeding

›Catheter-directed thrombolysis if systemic contraindicated

›Submassive PE (RV dysfunction, troponin positive)

›Anticoagulation primary treatment

›Systemic thrombolytics controversial; consider if clinical deterioration

›Low-risk PE

›LMWH: enoxaparin 1 mg/kg subcutaneous every 12 hours

›DOAC: rivaroxaban 15 mg twice daily x 21 days then 20 mg once daily

›Apixaban 10 mg twice daily x 7 days then 5 mg twice daily (alternative)

Musculoskeletal and GI treatment

›Non-cardiac etiologies

›Musculoskeletal

›Ibuprofen 400-600 mg every 6-8 hours with food

›Acetaminophen 500-1000 mg every 6 hours as alternative

›Topical NSAIDs as adjunct

›GERD/esophageal

›PPI: omeprazole 20-40 mg once daily

›Antacids: aluminum hydroxide/magnesium hydroxide suspension

›GI cocktail (antacid + viscous lidocaine +/- anticholinergic)

›GI cocktail response does NOT confirm GI etiology

09Special Populations/sp61

Pregnancy

›Physiologic changes and risk

›Cardiovascular physiology in pregnancy

›Increased plasma volume, heart rate, and cardiac output

›Reduced systemic vascular resistance

›Exacerbates underlying cardiac conditions

›Aortic dissection in pregnancy

›Peak risk: third trimester and peripartum

›Associated with connective tissue disorders, pre-eclampsia, bicuspid valve

›Type A: emergent surgical intervention; consider fetal delivery timing with obstetrics

›PE in pregnancy

›Increased VTE risk 5-fold during pregnancy and postpartum period

›D-dimer cutoffs not validated in pregnancy; YEARS algorithm validated

›CTPA or V/Q scan both acceptable; shield fetal field

›LMWH preferred anticoagulation; DOACs contraindicated

›ACS in pregnancy

›Rare but mortality higher than non-pregnant

›SCAD (spontaneous coronary artery dissection) more common in peripartum

›CTPA and coronary angiography with abdominal shielding acceptable if needed

›Medications in pregnancy

›Aspirin: safe in pregnancy

›P2Y12 inhibitors: limited data; use only if maternal benefit clearly outweighs risk

›Heparin and LMWH: safe; DOACs contraindicated

›Colchicine: limited safety data in pregnancy; consult rheumatology

›NSAIDs: avoid after 20 weeks gestational age (ductus arteriosus concern)

Geriatric

›Age-related considerations

›Atypical presentations

›Dyspnea, weakness, falls, altered mental status as ACS equivalents

›Classic chest pain absent in up to 30% of elderly MI patients

›MI prevalence ~4% in patients >=80 presenting with nontraumatic chest pain

›Medication management

›Reduced renal clearance: adjust LMWH, heparin, and contrast-requiring CT

›Beta-blockers: use lower starting doses; avoid in frailty with hypotension risk

›Morphine: increased sensitivity; use fentanyl or lower doses

›NSAID caution: renal toxicity, GI bleeding, HF exacerbation risk

›HEART score considerations

›Age >=65 years contributes maximum 2 points to HEART score

›Older patients more likely in intermediate and high-risk categories

›Troponin interpretation

›Baseline troponin elevation more common with CKD and prior cardiac injury

›Focus on delta (absolute change) rather than single elevated value

›Discharge planning

›Social support, mobility limitations, medication adherence

›Lower threshold for admission if uncertain follow-up

Pediatrics

›Age-specific considerations

›Epidemiology

›Chest pain in children and adolescents is rarely cardiac (<1-6% of cases)

›Most common causes: musculoskeletal (30%), idiopathic (30%), respiratory, GI

›Cardiac causes requiring recognition

›Myocarditis: troponin elevation, viral prodrome, dilated cardiomyopathy

›Kawasaki disease sequelae: coronary artery aneurysm in prior affected patients

›Congenital heart disease exacerbation or arrhythmia

›HCM: exertional pain, syncope, positive family history of sudden cardiac death

›Anomalous coronary arteries: exertional pain in young athletes

›Medication dosing

›Aspirin in ACS equivalent (rare): 3-5 mg/kg/day, max 81 mg/day for antiplatelet

›Ibuprofen for pericarditis or musculoskeletal: 10 mg/kg/dose every 6-8 hours (max 40 mg/kg/day)

›Heparin anticoagulation: 75 units/kg bolus then 20 units/kg/hour infusion, titrate to aPTT

›POCUS utility

›Highly useful to exclude effusion, wall motion abnormality, and structural disease

›Reassurance after cardiac workup

›Majority have benign etiology; clear communication with family

10Background/b68

Epidemiology

›Incidence and burden

›Chest pain accounts for >7.8 million ED visits annually in the United States

›Second most common ED complaint after abdominal pain

›Etiology distribution

›ACS approximately 10-15% of ED chest pain presentations

›Musculoskeletal and GI causes collectively account for majority of noncardiac cases

›Pericarditis up to 5% of nonischemic chest pain ED visits

›Age-specific MI prevalence in nontraumatic chest pain

›Ages 18-44: ~1% MI prevalence

›Ages >=80: ~4% MI prevalence

›Missed diagnosis risk

›Up to 6% of patients with ischemia discharged after single normal ECG

›Women, elderly, and diabetic patients at highest risk for missed ACS

›Mortality

›STEMI in-hospital mortality 3-5% with primary PCI

›Type A dissection without surgery: mortality ~1-2% per hour initially

›Massive PE in-hospital mortality 25-65%

Pathophysiology

›ACS mechanisms

›Atherosclerotic plaque rupture or erosion

›Platelet aggregation and thrombus formation at site of disruption

›Complete occlusion: STEMI with transmural ischemia

›Partial occlusion or distal embolization: NSTEMI or unstable angina

›Type 2 MI

›Myocardial oxygen demand-supply mismatch without plaque rupture

›Causes: tachyarrhythmia, severe anemia, hypotension, cocaine vasospasm

›Aortic dissection mechanism

›Intimal tear allows blood to enter medial layer

›DeBakey Type I: originates ascending, extends to descending

›DeBakey Type II: confined to ascending aorta

›DeBakey Type III: originates descending aorta

›Stanford Type A: involves ascending aorta (surgical)

›Stanford Type B: confined to descending aorta (medical)

›Risk of malperfusion

›Branch vessel occlusion: stroke, renal failure, ischemic limb, mesenteric ischemia

›PE mechanism

›Thrombus from deep venous system embolizes to pulmonary vasculature

›RV afterload increase leads to RV dilation and dysfunction

›Massive PE: obstructive shock with cardiovascular collapse

›Hypoxia mechanisms

›V/Q mismatch, atelectasis, reduced cardiac output

›Pericarditis mechanism

›Inflammation of pericardium from viral, autoimmune, or secondary causes

›Most common: viral (Coxsackievirus, echovirus, SARS-CoV-2)

›70-85% have benign course with standard treatment

Therapeutic Considerations

›Risk stratification evidence base

›HEART Pathway validation

›Prospective validation studies demonstrate 30-day MACE rate <1% in low-risk group

›2022 ACC Expert Consensus Decision Pathway endorses HEART Pathway

›2024 JACC validation study (Mahler et al): confirms safety of pathway

›hs-cTn algorithms

›ESC 0/1h and 0/2h algorithms reduce observation times

›Single hs-cTn at >=3 hours: reasonable to exclude myocardial injury (Class IIa)

›CCTA vs stress testing in intermediate risk

›CCTA reduces time to diagnosis by 50% vs nuclear stress testing

›2021 AHA/ACC Guideline: CCTA Class IIa for intermediate-risk patients

›Pericarditis treatment evidence

›COPE trial: colchicine added to NSAIDs reduces recurrence

›Recurrence rate reduced from 30% to 15%

›CORE trial: confirms colchicine benefit in recurrent pericarditis

›2024 JAMA review recommends colchicine 0.5 mg BID x 3 months standard of care

›Supplemental oxygen evidence

›AVOID-O2 and DETO2X-AMI trials

›Routine O2 in non-hypoxic ACS patients: no benefit, possible harm

›Supplemental O2 only for SpO2 <90%

›PE thrombolysis threshold

›Massive PE (hemodynamic compromise): systemic thrombolytics Class I

›Submassive PE: thrombolytics controversial; anticoagulation primary

›PEITHO trial: thrombolytics reduce hemodynamic collapse but increase bleeding

11Patient Discharge Instructions/pdi30

copy discharge instructions

›Chest Pain Discharge Instructions

›Your ED evaluation today for chest pain has been completed

›The tests performed today reduce but do not eliminate the possibility of a cardiac problem

›Follow-up with your family doctor or cardiologist within 7 days is important

›Return to the Emergency Department immediately if you experience

›Chest pain that returns, worsens, or feels different from today

›New shortness of breath or difficulty breathing

›Fainting, near-fainting, or loss of consciousness

›Palpitations or sensation of a rapid or irregular heartbeat

›Pain spreading to your arm, jaw, neck, or back

›Sweating with chest discomfort

›Nausea or vomiting with chest pain

›Activity and lifestyle guidance

›Avoid strenuous activity until cleared by your doctor

›If chest pain was diagnosed as musculoskeletal, rest and avoid heavy lifting for 1-2 weeks

›If pericarditis was diagnosed, avoid exercise until your doctor clears you and pain resolves

›Medications prescribed today

›Take medications exactly as directed

›Do not stop aspirin or other heart medications without speaking to your doctor

›If prescribed NSAIDs (ibuprofen), take with food to protect your stomach

›If prescribed colchicine, complete the full course as directed

›Diet and lifestyle

›If GI-related chest pain: avoid caffeine, alcohol, spicy and fatty foods, chocolate, and late-night meals

›If cardiac risk factors present: follow heart-healthy diet, reduce salt, quit smoking

›Avoid cocaine and stimulant drug use

›Important reminders

›A negative workup today means the tests today do not show an immediately dangerous cause

12References/r18

Guidelines and key sources

›Primary guidelines

›2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for Evaluation and Diagnosis of Chest Pain

›Gulati M, Levy PD, Mukherjee D, et al. Journal of the American College of Cardiology. 2021

›Recommends hs-cTn, CCTA for intermediate risk, and abandonment of "atypical" label

›2022 ACC Expert Consensus Decision Pathway on Evaluation and Disposition of Acute Chest Pain in ED

›Kontos MC, de Lemos JA, Deitelzweig SB, et al. Journal of the American College of Cardiology. 2022

›Endorses HEART Pathway; defines low, intermediate, high risk categories

›2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for Management of Patients with Acute Coronary Syndromes

›Rao SV, O'Donoghue ML, Ruel M, et al. Journal of the American College of Cardiology. 2025

›2024 AHA and American Red Cross Guidelines for First Aid

›Hewett Brumberg EK, Douma MJ, Alibertis K, et al. Circulation. 2024

›Key supporting references

›Hollenberg SM, Gentile F, Jumean M, et al. Navigating a Complicated World: AHA/ACC Chest Pain Guidelines. Chest. 2022

›Mahler SA, Ashburn NP, Supples MW, et al. Validation of ACC Expert Consensus Decision Pathway for Patients with Chest Pain. Journal of the American College of Cardiology. 2024

›Dawson LP, Smith K, Cullen L, et al. Care Models for Acute Chest Pain That Improve Outcomes and Efficiency. JACC State-of-the-Art Review. 2022

›Cremer PC, Klein AL, Imazio M. Diagnosis, Risk Stratification, and Treatment of Pericarditis: A Review. JAMA. 2024

›Buelt A, Kennady J, Arnold M. Chest Pain Evaluation: Updated Guidelines From the AHA/ACC. American Family Physician. 2023

›Nohria R, Viera AJ. Acute Coronary Syndrome: Diagnosis and Initial Management. American Family Physician. 2024

Evidence & Review