Chest Pain: A Comprehensive Overview

• ROSEN's Emergency Medicine, p. 1833
• Goldman-Cecil Medicine, p. 2503

Pathophysiology of Chest Pain

• Pain from any of these organs produces the same indistinct quality and location
• Dorsal segments overlap 3 levels above and below, so thoracic disease can produce pain anywhere from the jaw to the epigastrium
• Radiation to the arms, shoulders, and neck occurs because somatic afferent fibers synapse in the same dorsal root ganglia as thoracic viscera, creating referred pain patterns
• ROSEN's Emergency Medicine, p. 1843-1845

Differential Diagnosis (Anatomical Framework)

A. Skin

• Herpes zoster (pain may precede rash by 1-2 days)

B. Breast

• Fibroadenoma, mastitis, gynecomastia

C. Musculoskeletal

• Costochondritis (most common benign cause)
• Tietze syndrome
• Precordial catch syndrome
• Pectoral muscle strain
• Rib fracture
• Cervical/thoracic spondylosis (C4-T6)
• Myositis

D. Esophageal

• Esophageal spasm (can closely mimic angina)
• GERD/esophagitis
• Esophageal rupture (Boerhaave syndrome - life-threatening)
• Esophageal neoplasm

E. Gastrointestinal

• Peptic ulcer disease
• Gallbladder disease / cholecystitis
• Pancreatitis
• Liver/subdiaphragmatic abscess

F. Pulmonary

• Pleuritis (pleuritic pain - sharp, worsens with breathing/coughing)
• Pleural effusion
• Pneumonia
• Pneumothorax (sudden onset, unilateral, with dyspnea)
• Pulmonary embolism
• Pulmonary hypertension
• Neoplasm

G. Cardiac (Most Critical)

• Acute coronary syndrome (ACS) - UA, NSTEMI, STEMI
• Stable angina
• Pericarditis
• Myocarditis
• Aortic stenosis / valve disease

H. Vascular

• Aortic dissection (sudden, tearing, radiates to back - life-threatening)

I. Other

• Anxiety/panic disorder
• Mediastinal mass
• Cardiac neurosis
• Symptom to Diagnosis, p. 3214-3260

The "Must Not Miss" Diagnoses (Life-Threatening)

• Goldman-Cecil Medicine, p. 2505-2509

Key Historical Features

Character and Quality

• Pressure / squeezing / constricting: highly suggestive of myocardial ischemia
• Sharp / stabbing / pleuritic (worse with breathing): pleural, pericardial, musculoskeletal
• Tearing / ripping: aortic dissection
• Burning: GERD, esophagitis
• Electric / lancinating: intercostal neuritis, herpes zoster

Diamond & Forrester Classification of Angina

1. Typical angina (all 3 criteria): (1) substernal pressure-like discomfort, (2) precipitated by exertion or emotional stress, (3) relieved by rest or nitroglycerin within 30 minutes
2. Atypical angina: 2 of the 3 criteria
3. Non-cardiac chest pain: only 1 criterion

• Fuster and Hurst's The Heart, p. 1389

Duration

• Angina: typically < 5 minutes, relieved by rest or nitrates
• UA/NSTEMI: > 20 minutes at rest
• Pain lasting hours to days without troponin elevation or ECG changes strongly argues against ischemia
• ACS pain may build gradually over several minutes and does not resolve with rest

Location and Radiation

• Substernal radiating to left arm, neck, jaw: classic ischemia
• Radiating to the back: aortic dissection or posterior MI
• Ipsilateral shoulder: diaphragmatic pleurisy
• Epigastric: inferior MI, GERD, peptic ulcer

Precipitating / Relieving Factors

• Exertion, cold, emotions, heavy meals -> ischemia
• Leaning forward relieves -> pericarditis
• Antacids relieve -> esophageal/GI cause
• Reproducible with palpation -> musculoskeletal (costochondritis)
• Deep breathing worsens -> pleurisy, pneumothorax, pericarditis
• Valsalva relieves -> precordial catch syndrome

Associated Symptoms

• Diaphoresis, nausea, vomiting: MI
• Dyspnea: PE, pneumothorax, MI, heart failure
• Hemoptysis: PE, lung malignancy, tuberculosis
• Syncope: severe AS, HOCM, massive PE
• Fever + pleuritic pain: pneumonia, pericarditis, pleuritis

Pleuritic vs. Cardiac vs. Musculoskeletal Pain

• Murray & Nadel's Respiratory Medicine, p. 3519-3548

Diagnostic Approach

Initial Stabilization

1. Appearance - distress, pallor, diaphoresis
2. Vital signs - BP in both arms (dissection), O2 saturation, HR
3. ECG - must be performed and read immediately for ALL chest pain patients

First-Line Investigations

• ECG: ST elevation (STEMI), ST depression/T-wave changes (NSTEMI/UA), saddle-shaped ST elevation (pericarditis), S1Q3T3 (PE)
• Troponin (high-sensitivity): rises within 1-3 hours of MI onset; serial measurements at 0h and 3h (or 0h/1h with hs-cTnI)
• CXR: pneumothorax, widened mediastinum (dissection), pleural effusion, pulmonary infiltrates
• BNP / NT-proBNP: if heart failure suspected
• D-dimer: rule out PE in low-to-moderate pretest probability
• ABG: if PE or significant respiratory compromise suspected

Further Investigations (Based on Suspected Diagnosis)

• CT pulmonary angiography (CTPA): gold standard for PE
• CT aortography: aortic dissection
• Echocardiography: wall motion abnormalities (ischemia), pericardial effusion, tamponade, aortic valve assessment
• Exercise stress test / stress echocardiography: stable chest pain evaluation for ischemia
• Coronary angiography: definitive diagnosis of CAD; also therapeutic (PCI)
• Esophageal manometry / pH monitoring: esophageal spasm, GERD
• Upper GI endoscopy: esophagitis, PUD

Specific Diagnoses in Detail

1. Acute Coronary Syndrome (ACS)

• The most feared cause of chest pain
• STEMI: complete occlusion; ECG shows ST elevation in 2+ contiguous leads
• NSTEMI: partial occlusion; troponin elevated but no ST elevation
• UA: no troponin elevation; rest pain or accelerating pattern
• Plaque rupture can occur on hemodynamically insignificant lesions, causing sudden-onset rest pain with no prior history
• Women, elderly, and diabetic patients may present atypically with fatigue, dyspnea, nausea without classic pain

2. Aortic Dissection

• Classically sudden, severe, "tearing" or "ripping" pain
• Ascending dissection (Type A): chest pain radiating to back; risk of AR, tamponade, stroke
• Descending dissection (Type B): back pain radiating to abdomen
• Key exam: BP differential > 20 mmHg between arms, pulse deficits
• Risk factors: hypertension, Marfan syndrome, bicuspid aortic valve, pregnancy
• Confirm with CT aortography, TEE, or MRI

3. Pulmonary Embolism

• Pleuritic chest pain (unilateral, sharp, worse with breathing) + dyspnea + hypoxia
• Hemoptysis in pulmonary infarction
• ECG: sinus tachycardia (most common); S1Q3T3 (rare but classic); right heart strain pattern
• Wells score / Geneva score for pretest probability; D-dimer to rule out; CTPA to confirm

4. Pericarditis

• Sharp, retrosternal pain; characteristically relieved by sitting up and leaning forward
• Pericardial friction rub on auscultation (pathognomonic)
• ECG: diffuse saddle-shaped ST elevation + PR depression
• Causes: viral (most common), autoimmune, post-MI (Dressler), uremia, malignancy

5. Stable Angina

• Episodic substernal pressure-like chest discomfort
• Precipitated by exertion, cold, emotion, heavy meals
• Relieved within 5 minutes by rest or sublingual nitroglycerin
• Progressive increase in frequency with decreasing exertion threshold suggests worsening CAD

6. GERD / Esophageal Causes

• Burning substernal discomfort; worse after meals and lying down
• Esophageal spasm can cause severe pressure-like pain mimicking angina; may even respond to nitroglycerin
• GERD is one of the most common non-cardiac causes of chest pain in ambulatory settings

7. Musculoskeletal (Costochondritis / Tietze Syndrome)

• Tendernesss reproducible on palpation of the costochondral junction
• No radiation, no diaphoresis, not exertional
• Tietze syndrome includes visible/palpable swelling at the affected joint (usually 2nd/3rd ribs)

Special Considerations

Women and Atypical Presentation

Elderly and Diabetic Patients

Variant (Prinzmetal) Angina

Summary: Rapid Clinical Framework

Chest Pain
├── ACUTE onset + hemodynamically unstable?
│   └── ECG → ACS / tension pneumothorax / tamponade
├── Sudden tearing + hypertension + back radiation?
│   └── Aortic Dissection (CT aortography)
├── Pleuritic + dyspnea + hypoxia + risk factors?
│   └── Pulmonary Embolism (D-dimer → CTPA)
├── Sharp + worse lying flat + better leaning forward + friction rub?
│   └── Pericarditis (ECG + Echo)
├── Exertional pressure + relieves with rest/nitrates?
│   └── Angina (ACS vs. stable) → troponin + stress test
├── Burning + worse after meals/lying down?
│   └── GERD / esophageal cause
└── Reproducible on palpation + recent activity?
    └── Musculoskeletal (costochondritis, Tietze)

• Symptom to Diagnosis: An Evidence-Based Guide, 4th Ed. - Chest Pain chapter
• Goldman-Cecil Medicine, International Edition - Chapter 39
• ROSEN's Emergency Medicine, 9th Ed. - Chapter 22
• Murray & Nadel's Textbook of Respiratory Medicine - Chapter on Chest Pain Syndromes
• Fuster and Hurst's The Heart, 15th Ed. - Chapter 2