What is the diagnosis and treatment for a patient with left chest pain radiating to the left arm, aggravated by bending for 2 weeks?

Differential Diagnosis and Management of Left Chest Pain Radiating to Left Arm Aggravated by Bending

This patient requires immediate evaluation for acute coronary syndrome (ACS), but the aggravation by bending strongly suggests a musculoskeletal or gastrointestinal etiology rather than cardiac ischemia—however, cardiac causes must be definitively ruled out first given the classic radiation pattern. 1, 2

Immediate Risk Stratification

High-Priority Cardiac Evaluation Required

• Obtain a 12-lead ECG within 10 minutes to identify ST-elevation myocardial infarction (STEMI), ST depression, or other ischemic changes 1, 2
• Measure cardiac troponin immediately and repeat according to protocol, as elevated troponin with typical chest pain indicates NSTEMI 2
• The classic presentation of substernal chest pain radiating to the left arm has high likelihood for ACS, with diaphoresis having 95% specificity (LR 5.18) 2
• However, pain aggravated by bending forward is a presumptive sign of nonanginal chest pain and argues against cardiac ischemia 3

Key Historical Features to Distinguish Cardiac from Non-Cardiac

Features suggesting NON-cardiac origin (present in this case):

• Aggravation by bending forward is highly characteristic of nonanginal pain 3
• Pain duration of 2 weeks with intermittent pattern (cardiac ischemia typically presents as crescendo pattern over 48 hours or acute onset) 1
• Chest pain is very likely nonanginal if it can be brought on by movement of the trunk or arm, or by bending forward 3

Features that would suggest cardiac origin (assess for these):

• Pain lasting >20 minutes at rest suggests possible myocardial infarction 1
• Pressure, oppression, or heaviness quality (rather than sharp or positional) 2
• Precipitation by exertion or emotional stress with relief by rest 1
• Associated symptoms: diaphoresis, nausea, dyspnea, lightheadedness 1

Differential Diagnosis Algorithm

1. Acute Pericarditis (Most Likely Given Clinical Features)

• Sharp, pleuritic chest pain that worsens in supine position and improves when sitting up and leaning forward is diagnostic of acute pericarditis 2
• The aggravation by bending in this patient fits this pattern
• ECG may show diffuse ST elevation with PR depression 2
• Requires echocardiography to assess for pericardial effusion 2

2. Gastroesophageal Reflux Disease (GERD)

• Epigastric or substernal pain that can radiate to left arm 4
• Bending forward increases intra-abdominal pressure and can precipitate GERD symptoms 4
• Does not typically cause true left arm radiation but can mimic cardiac pain 3
• Trial of proton pump inhibitor therapy may be diagnostic and therapeutic 4

3. Musculoskeletal Pain

• Pain reproducible with palpation and worsening with specific movements suggests musculoskeletal origin 4
• Positional chest pain is usually nonischemic 4
• Costochondritis or chest wall strain can radiate along intercostal nerves
• Physical examination should assess for chest wall tenderness 1

4. Unstable Angina/NSTEMI (Must Rule Out)

• Chest or left arm pain as chief symptom with known CAD history, age >70, male sex, or diabetes indicates intermediate-to-high likelihood 1
• Patients with substernal or left chest pain with radiation to left arm have <10% chance of right coronary artery disease but significant risk of left-sided coronary disease 5
• Absence of pain at rest >20 minutes and lack of accelerating tempo over 48 hours makes this less likely 1

Recommended Diagnostic Workup

Immediate (Emergency Department Evaluation)

1. 12-lead ECG within 10 minutes 1, 2
2. Cardiac troponin measurement (immediate and repeat per protocol) 2
3. Chest radiograph to evaluate for pneumothorax, pneumonia, or mediastinal widening 2
4. Focused cardiovascular examination for murmurs, rales, signs of heart failure 1

If Initial Cardiac Workup Negative

1. Assess for pericardial friction rub on examination 2
2. Transthoracic echocardiography if pericarditis suspected 2
3. Chest wall palpation to reproduce pain and identify musculoskeletal source 1, 4
4. Trial of proton pump inhibitor if GERD suspected after cardiac exclusion 4

Critical Pitfalls to Avoid

• Do not rely on nitroglycerin response as diagnostic criterion—esophageal spasm and other conditions also respond to nitroglycerin 1, 3
• Do not assume positional pain excludes cardiac disease until troponin and ECG are definitively negative 1
• Do not delay emergency evaluation for chest pain with classic radiation pattern, even if features suggest non-cardiac etiology 1
• Pain aggravated by bending is a strong indicator of non-cardiac origin, but this must be confirmed with objective testing, not assumed 3

Disposition Decision

• If troponin elevated or ECG shows ischemic changes: Admit for ACS management per cardiology protocols 1, 2
• If cardiac workup negative and pericarditis suspected: Consider admission or close outpatient follow-up depending on hemodynamic stability 2
• If cardiac and pericardial causes excluded: Outpatient management with PPI trial for GERD or NSAIDs for musculoskeletal pain with close follow-up 4