What is the approach to assessment and management of a patient with chest pain radiating into the left arm?

Assessment and Management of Chest Pain Radiating to Left Arm

Chest pain radiating to the left arm should be treated as a potential acute coronary syndrome (ACS) until proven otherwise, requiring immediate ECG, cardiac biomarkers, and risk stratification.

Initial Assessment

History

• Characteristics of chest pain:

  • Nature: Retrosternal discomfort, pressure, heaviness, tightness, squeezing 1
  • Onset and duration: Typically gradual onset lasting ≥10 minutes 1
  • Location: Retrosternal with radiation to left arm, neck, jaw, or back 1
  • Precipitating factors: Physical exertion, emotional stress, or occurring at rest 1
  • Relieving factors: May not be relieved by rest or nitroglycerin in ACS 1

• Associated symptoms:

  • Diaphoresis (cold sweat), nausea, vomiting, dyspnea, lightheadedness, syncope 1
  • Women, elderly, and diabetic patients may present with atypical symptoms 2

Physical Examination

• Vital signs: Check for hypotension, tachycardia, or narrow pulse pressure 1
• Cardiovascular: Listen for S3, new murmurs, or basal rales 1
• Look for signs of autonomic activation (pallor, sweating) 1

Immediate Diagnostic Tests

1. 12-lead ECG within 10 minutes of arrival 1

   • Look for ST-segment elevation/depression, T-wave inversion, or new LBBB
   • Consider additional leads (V7-V9) if posterior MI suspected 1, 2

2. Cardiac biomarkers (preferably high-sensitivity troponin)

   • Initial and serial measurements (0,3, and 6 hours) 2
   • Do not delay treatment while waiting for results if clinical suspicion is high 2

3. Chest X-ray to exclude other causes (aortic dissection, pneumothorax) 1

Risk Stratification

High-Risk Features (requiring immediate intervention) 1:

• Recurrent/ongoing chest pain
• Marked ST-segment depression
• Hemodynamic instability
• Heart failure
• Ventricular arrhythmias
• Elevated troponin levels
• Diabetes mellitus

Risk Assessment Tools

• HEART score: History, ECG, Age, Risk factors, Troponin 3
• TIMI score: Age, risk factors, known CAD, ASA use, severe angina, ECG changes, cardiac markers 3

Management Algorithm

Immediate Management

1. For all suspected ACS patients:

   • Aspirin 250-500mg chewed 1
   • Supplemental oxygen if saturation <90% 1
   • IV access
   • Continuous cardiac monitoring 1
   • Pain relief with nitrates (sublingual or IV) and opioids if needed 1

2. If ST-segment elevation present:

   • Immediate reperfusion therapy (primary PCI preferred) 1
   • If PCI not available within 120 minutes, consider fibrinolysis 1

3. If no ST-segment elevation but high-risk features:

   • Antiplatelet therapy (aspirin + P2Y12 inhibitor) 1
   • Anticoagulation with heparin (unfractionated or LMWH) 1
   • Early invasive strategy (coronary angiography within 24 hours) 1

Subsequent Management

• For confirmed NSTE-ACS: Beta-blockers, statins, ACE inhibitors/ARBs 1
• For low-risk patients: Consider non-invasive testing (stress test, coronary CT) 1

Common Pitfalls to Avoid

1. Dismissing cardiac causes due to young age or atypical presentation 2

   • Women, elderly, and diabetic patients often present with atypical symptoms

2. Relying solely on initial ECG 2

   • ECG may be normal or non-diagnostic early in ACS
   • Obtain serial ECGs, especially during pain

3. Misattributing symptoms to non-cardiac causes 2

   • Especially gastrointestinal symptoms or musculoskeletal pain

4. Overlooking posterior MI 2

   • May present with interscapular pain and ST depression in V1-V3 rather than elevation
   • Consider additional posterior leads (V7-V9)

5. Delaying treatment while waiting for troponin results 2

   • Initial troponin may be normal in early ACS

Chest pain radiating to the left arm is a classic presentation of ACS, but the diagnosis requires a systematic approach using clinical assessment, ECG, and cardiac biomarkers. Early recognition and appropriate management significantly reduce morbidity and mortality in these patients.