I have left-sided chest pain radiating to my axilla and breast; what could be causing it and how should I manage it?

Left-Sided Chest Pain Radiating to Axilla and Breast: Immediate Evaluation and Management

You must obtain a 12-lead ECG within 10 minutes and measure high-sensitivity cardiac troponin immediately to exclude acute coronary syndrome, even though your pain radiates to the axilla and breast—a pattern that can represent either cardiac ischemia or musculoskeletal disease. 1

Immediate Life-Threatening Exclusions Required

Your symptom pattern—left chest pain with radiation to the axilla and breast—overlaps with multiple diagnoses, some immediately fatal. The 2021 AHA/ACC Chest Pain Guideline mandates rapid identification of acute coronary syndrome, aortic dissection, pulmonary embolism, tension pneumothorax, and esophageal rupture because any can progress to death within minutes to hours without treatment. 1, 2

Acute Coronary Syndrome Assessment

• Classic anginal pain radiates to the left arm, neck, or jaw, but radiation to the axilla and breast also occurs, particularly in women, elderly patients, and those with diabetes who frequently present with atypical patterns including sharp or stabbing pain in the left or right chest. 1
• Approximately 13% of patients with pleuritic-type chest pain still have acute myocardial ischemia, so sharp quality does not rule out ACS. 1, 2
• Associated symptoms that markedly increase ACS likelihood include diaphoresis, dyspnea, nausea, vomiting, lightheadedness, presyncope, syncope, palpitations, or upper abdominal discomfort. 1
• A completely normal physical examination does not exclude uncomplicated myocardial infarction; however, findings such as diaphoresis, tachycardia, hypotension, pulmonary crackles, an S3 gallop, or a new mitral regurgitation murmur strongly suggest ACS. 1, 2

Other Immediately Fatal Causes

• Aortic dissection presents with sudden "ripping" or "tearing" chest or back pain maximal at onset, pulse differentials between extremities (≈30% of patients), systolic blood-pressure difference >20 mmHg between arms, and a new aortic regurgitation murmur (40–75% of type A dissections). 1, 2
• Pulmonary embolism causes acute dyspnea with pleuritic chest pain; tachycardia occurs in >90% of patients and tachypnea in ≈70%. 1, 2
• Tension pneumothorax produces dyspnea and sharp chest pain worsening with inspiration, unilateral absence of breath sounds, and hemodynamic instability. 1, 2

Algorithmic Diagnostic Approach (First 10 Minutes)

Step 1: Obtain a 12-lead ECG within 10 minutes and interpret for ST-elevation, ST-depression, T-wave inversion, new left bundle-branch block, or other acute ischemic changes. 1

Step 2: Measure high-sensitivity cardiac troponin immediately; it is the most sensitive and specific biomarker for myocardial injury. 1, 2

Step 3: Assess vital signs including oxygen saturation and blood pressure in both arms to detect pulse or pressure differentials suggestive of aortic dissection. 2

Step 4: Perform a focused cardiovascular examination for new murmurs, pericardial friction rubs, unilateral breath sounds, signs of heart failure, and hemodynamic instability. 1, 2

Step 5: If the initial ECG is nondiagnostic but clinical suspicion remains high, obtain serial ECGs every 15–30 minutes to capture evolving ischemic patterns. 1

Step 6: If the ECG shows ST-elevation or new ischemic changes OR troponin is elevated, activate emergency medical services for immediate transport to an emergency department and initiate dual antiplatelet therapy (aspirin plus P2Y12 inhibitor) and anticoagulation. 2, 3

Step 7: If the initial troponin is normal, repeat measurement at 3–6 hours; a single normal high-sensitivity troponin does not rule out ACS. 1, 2

Pain Characteristics That Guide Differential Diagnosis

Features Suggesting Cardiac Ischemia

• Gradual onset over several minutes (not seconds) of retrosternal pressure, heaviness, tightness, or squeezing that radiates to the left arm, axilla, neck, jaw, or breast. 1
• Pain lasting >20 minutes at rest suggests possible myocardial infarction. 1, 3
• Precipitation by physical exertion or emotional stress; occurrence at rest or with minimal exertion indicates acute coronary syndrome. 1

Features Suggesting Non-Cardiac Etiology

• Sharp chest pain that increases with inspiration and lying supine is unlikely related to ischemic heart disease and suggests acute pericarditis. 1
• Fleeting chest pain lasting only seconds is unlikely related to ischemic heart disease. 1
• Pain localized to a very limited area or radiating below the umbilicus or hip is unlikely related to myocardial ischemia. 1
• Positional chest pain (worse with specific movements, turning, twisting, or bending) is usually nonischemic and suggests musculoskeletal origin. 1
• Pain reproducible with palpation of the chest wall or costochondral junctions indicates costochondritis, which accounts for approximately 43% of chest-pain presentations in primary care after cardiac causes are excluded. 2

Serious Non-ACS Cardiac Causes

Pericarditis

• Sharp, pleuritic chest pain that worsens when lying supine and improves when sitting or leaning forward is the hallmark presentation. 1, 2, 4
• A pericardial friction rub may be audible on auscultation, though its absence does not exclude disease. 1, 2
• Fever commonly accompanies pericarditis. 1, 2
• ECG may show diffuse ST-segment elevation and PR-segment depression. 2, 4

Myocarditis

• Presents with chest pain, fever, and signs of heart failure such as an S3 gallop; clinical presentation can mimic ACS, necessitating troponin measurement for differentiation. 1, 2

Common Benign Causes

Costochondritis / Tietze Syndrome

• Tenderness of costochondral joints on palpation and pain reproducible with chest wall pressure are diagnostic. 1, 2
• Pain is affected by palpation, breathing, turning, twisting, or bending. 1, 2
• However, up to 7% of patients with reproducible chest-wall tenderness still have ACS, so reproducible tenderness does not fully exclude cardiac disease. 2

Gastroesophageal Reflux Disease (GERD)

• Burning retrosternal pain related to meals or occurring at night; stress may exacerbate symptoms, and antacids often provide relief. 1, 2, 3
• Bending forward increases intra-abdominal pressure and can precipitate GERD symptoms. 3

Critical Pitfalls to Avoid

• Do not rely on nitroglycerin response to differentiate cardiac from non-cardiac chest pain, as esophageal spasm and other conditions also respond to nitroglycerin. 1, 2, 3, 4
• Do not dismiss ACS in women, elderly patients, or individuals with diabetes based on atypical presentations; they frequently present with non-classic symptoms such as sharp or stabbing pain on the left or right side of the chest, throat discomfort, or abdominal pain. 1, 2
• Do not assume a normal physical examination excludes ACS; uncomplicated myocardial infarction can present with a completely normal exam. 1, 2
• Do not assume sharp or pleuritic pain excludes ACS; approximately 13% of patients with pleuritic-type pain have myocardial ischemia. 1, 2
• A normal initial ECG does not exclude ACS; 30–40% of acute myocardial infarctions present with a normal or nondiagnostic ECG, and approximately 5% of ACS patients have a normal first ECG. 2

Risk Stratification After Initial Evaluation

High-Risk Features Requiring Immediate Emergency Department Transfer by EMS

• ST-segment elevation or new ischemic changes on ECG. 1, 2, 3
• Elevated cardiac troponin (≥99th percentile). 2
• Hemodynamic instability (hypotension, shock). 1, 2
• Associated diaphoresis, dyspnea, nausea, syncope, or age >75 years with accompanying symptoms. 2

Low-Risk Profile (Normal ECG and Serial Troponins)

• Define low-risk criteria as: normal or nondiagnostic ECG, negative troponin at presentation and at 3–6 hours, stable vital signs, no ongoing pain, and absence of heart-failure signs. 2
• Manage low-risk patients by observing in a chest-pain unit for 10–12 hours or discharge with outpatient stress testing or coronary CT angiography within 72 hours. 2

Management Summary

If both ECG and serial troponins (at 0 and 3–6 hours) are normal AND pain is reproducible with chest-wall palpation, diagnose costochondritis, prescribe NSAIDs (e.g., ibuprofen 600–800 mg three times daily for 1–2 weeks), advise temporary avoidance of aggravating movements, and arrange outpatient stress testing or coronary CT angiography within 72 hours if cardiovascular risk factors are present. 2

If both troponins are normal but pain is not reproducible, schedule urgent (24–48 hour) stress testing or coronary CT angiography. 2

If pericarditis is suspected (sharp, positional pain worse supine, better leaning forward), initiate anti-inflammatory therapy with ibuprofen 600–800 mg three times daily for 1–2 weeks or colchicine 0.6 mg twice daily for 3 months, and consider admission or close outpatient follow-up depending on hemodynamic stability. 2, 3, 4