Chest Pain

OVERVIEW

Acute chest pain encompasses any visceral or somatic pain, pressure, tightness, or discomfort originating between the level of the lower jaw and the epigastrium.

The primary objective in evaluating acute chest pain is to rapidly identify or exclude the “Big 6” life-threatening emergencies before considering benign or musculoskeletal etiologies.

Cardiac causes account for ~15–20% of emergency chest pain presentations, but non-cardiac causes (Gastroesophageal, Musculoskeletal, Psychiatric) account for >50%.

APPROACH

Step 1: Immediate Triage & Primary Survey (ABCDE)

• Obtain 12-Lead ECG within 10 minutes of presentation.
• Attach continuous cardiac monitoring, pulse oximetry, and BP cuff. Secure IV access.
• Screen for Immediate Resuscitation Features:
  • Unstable Vitals / Shock (SBP < 90 mmHg, HR > 120 or < 50 bpm, SpO2 < 93%).
  • Severe dyspnea / altered consciousness / diaphoresis.

Step 2: Rule Out the “Big 6” Life-Threatening Emergencies

• 1. Acute Coronary Syndrome (ACS): ST elevation / depression or T-wave inversion on ECG; retrosternal crushing pain.
• 2. Acute Aortic Dissection: Sudden tearing pain radiating to back; BP differential > 20 mmHg between arms or pulse deficit.
• 3. Pulmonary Embolism (PE): Pleuritic chest pain, dyspnea, tachycardia, hypoxia, swollen leg (DVT).
• 4. Tension Pneumothorax: Unilateral absent breath sounds, hyper-resonance, hypotension, tracheal shift.
• 5. Cardiac Tamponade: Beck’s Triad (Hypotension + Distended neck veins + Muffled heart sounds); eFAST positive.
• 6. Esophageal Perforation (Boerhaave): Severe sudden epigastric/chest pain post-retching, subcutaneous emphysema.

Step 3: Diagnostic Branching Logic

• ST-Elevation on ECG (STEMI): -> Code STEMI / Immediate Cath Lab transfer for primary PCI (target FMC-to-device < 90 min) OR thrombolysis if PCI unavailable < 120 min.
• Hemodynamically Unstable / Asymmetrical Pulses / Widened Mediastinum: -> Emergency CT Aortogram (rule out Aortic Dissection).
• Hypoxia / Tachycardia / High Wells Score: -> CT Pulmonary Angiogram (CTPA).
• Stable with Normal Initial ECG: -> Serial high-sensitivity Troponin protocol + Risk Stratification (HEART Score).

DIFFERENTIAL DIAGNOSIS

Cardiovascular (Life-Threatening):

• Acute Coronary Syndrome (STEMI / NSTEMI / Unstable Angina):
  • Distinguishing features: Heavy, retrosternal crushing pressure/tightness radiating to left arm/jaw, exertional onset, diaphoresis, nausea.
• Acute Aortic Dissection (Type A vs. Type B):
  • Distinguishing features: Sudden-onset (“maximal at onset”), “tearing” or “ripping” pain radiating between scapulae; inter-arm SBP difference > 20 mmHg, new aortic regurgitation murmur, or neurological deficit.
• Acute Pericarditis / Myocarditis:
  • Distinguishing features: Sharp, retrosternal pain worse on lying flat, relieved by sitting forward; friction rub on auscultation; diffuse concave ST elevation with PR depression across multiple leads on ECG.

Pulmonary (Life-Threatening):

• Pulmonary Embolism (PE):
  • Distinguishing features: Sudden-onset pleuritic (sharp, inspiration-dependent) chest pain, dyspnea, tachycardia, hemoptysis; history of recent surgery, immobility, malignancy, or DVT.
• Tension Pneumothorax:
  • Distinguishing features: Acute pleuritic pain, respiratory distress, ipsilateral hyper-resonance with absent breath sounds, severe hypotension, contralateral tracheal deviation.

Gastrointestinal & Non-Life-Threatening Causes:

• Esophageal Perforation (Boerhaave Syndrome):
  • Distinguishing features: History of severe vomiting/retching followed by sudden chest/epigastric pain, neck subcutaneous emphysema (Mackler’s triad: vomiting, chest pain, subcutaneous emphysema).
• Gastroesophageal Reflux Disease (GERD) / Esophageal Spasm:
  • Distinguishing features: Burning epigastric pain, acid regurgitation, worse lying flat post-meals; relieved by antacids. (Note: Esophageal spasm can respond to nitroglycerin, mimicking angina!).
• Musculoskeletal Chest Wall Pain (Costochondritis / Tietze Syndrome):
  • Distinguishing features: Sharp, localized pain reproducible by direct palpation of costochondral joints; no systemic features.

CAUSES OF CHEST PAIN BY BODY SYSTEMS
Cardiac	Respiratory	Gastrointestinal	Musculoskeletal	Psychogenic
Acute Coronary Syndrome	Pulmonary Embolism	Oesophageal rupture	Rib Fracture	Anxiety
Aortic dissection	Pneumothorax	Pneumomediastinum	Herpes Zoster	Panic attack
Pericarditis	Pulmonary Hypertension	Cholecystitis	Costochondritis
Stable Angina	Pneumonia	GERD/GORD
Endocarditis	Lung Cancer	Peptic ulcer disease
Cardiac tamponade	Bronchiectasis	Acute Pancreatitis

INVESTIGATIONS

First-Line / Bedside & Emergency Diagnostics:

• 12-Lead ECG (Repeat every 15–30 min if ongoing pain): Look for ST elevation, ST depression, T-wave inversion, new LBBB, or Wellens/De Winter signs.
• High-Sensitivity Troponin (hs-cTnT or hs-cTnI): Serial testing at 0h and 1h (or 0h and 3h). Rising delta confirms acute myocardial injury.
• Bedside eFAST / Point-of-Care Ultrasound (POCUS): Evaluate for pericardial effusion/tamponade, RV strain (McConnell’s sign in PE), lung sliding (pneumothorax), and aortic root diameter.
• Basic Bloods: FBC, U&E, Glucose, Lipids, Coagulation profile, D-Dimer (only if low/intermediate probability for PE).
• Portable Chest X-Ray: Screen for pneumothorax, widened mediastinum (> 8 cm), cardiomegaly, pulmonary edema, or pneumonia.

Targeted / Diagnostic Imaging Strategy:

• CT Pulmonary Angiography (CTPA): Gold standard for Pulmonary Embolism in patients with high Wells score or positive D-dimer.
• Triple-Rule-Out CT Angiography: Single ECG-gated scan evaluating Coronary Arteries (ACS), Thoracic Aorta (Dissection), and Pulmonary Arteries (PE) in high-risk equivocal cases.
• Formal Transthoracic / Transesophageal Echocardiography: Assesses regional wall motion abnormalities (RWMA), ejection fraction, valvular disease, or aortic root dilation.

CRITICAL MANAGEMENT

Acute Coronary Syndrome (Immediate ED Stabilization):

• Aspirin: 300 mg PO chewed immediately (unless severe allergy or active dissection).
• Second Antiplatelet (P2Y12 inhibitor): Ticagrelor 180 mg PO or Clopidogrel 300–600 mg PO (after discussion with interventional cardiology).
• Anticoagulation: Unfractionated Heparin (UFH) IV or LMWH (Enoxaparin 1 mg/kg SC) for NSTEMI/STEMI.
• Nitrates (GTN): Sublingual GTN 0.4 mg spray every 5 min (up to 3 doses) for ischemic pain.
  • Contraindication: Do NOT give nitrates if Right Ventricular Infarction (inferior STEMI with ST elevation in V4R) or recent Sildenafil/PDE-5 inhibitor use (causes severe profound hypotension).
• Supplemental O2: Administer only if SpO2 < 93% (hyperoxia causes coronary vasoconstriction).

Acute Aortic Dissection:

• Impulse Control: Administer IV short-acting beta-blocker (e.g., Esmolol or Labetalol) to target HR < 60 bpm and SBP 100–120 mmHg within 20 minutes to reduce aortic wall shear stress.