What is the best course of action for a patient with intermittent left-sided chest pain that is pulsating and sharp at times, without evidence of costochondritis (inflammation of the cartilage that connects the ribs to the breastbone) or shortness of breath, and with a normal body mass index (BMI)?

Evaluation and Management of Intermittent Left-Sided Chest Pain

This patient requires urgent cardiac evaluation with ECG and troponin measurement to exclude acute coronary syndrome (ACS), as the intermittent, sharp, pulsating nature of the pain does not reliably exclude cardiac ischemia, particularly since the pain occurs at rest and without clear triggers. 1

Immediate Diagnostic Workup Required

ECG Within 10 Minutes

• An ECG must be obtained and interpreted within 10 minutes to identify ST-segment elevation myocardial infarction (STEMI), ST-segment depression, T-wave inversions, or other ischemic changes 1
• If the initial ECG is nondiagnostic, serial ECGs should be performed to detect evolving ischemic changes 1
• The ECG may be completely normal in uncomplicated acute myocardial infarction, so a normal tracing does not exclude cardiac pathology 1

Cardiac Troponin Measurement

• Cardiac troponin T or I should be measured as soon as possible after presentation to detect myocardial injury 1
• A second troponin measurement should be obtained 6-12 hours after symptom onset if the initial value is normal 1
• Elevated troponin indicates irreversible myocardial damage and confirms myocardial infarction 1

Critical Clinical Features That Guide Diagnosis

Characteristics That Make ACS Less Likely (But Do Not Exclude It)

• Sharp chest pain that increases with inspiration typically suggests pericarditis rather than ischemic heart disease 1
• Pain localized to a very limited area is unlikely related to myocardial ischemia 1
• Fleeting chest pain lasting only seconds is unlikely related to ischemic heart disease 1
• Positional chest pain usually indicates a nonischemic etiology such as musculoskeletal causes 1

Red Flags for Life-Threatening Conditions

• Pulsating pain can occur with aortic dissection, though this typically presents with sudden-onset "ripping" pain radiating to the back 1
• Pain occurring at rest or with minimal exertion suggests ACS rather than stable angina 1
• Associated symptoms such as dyspnea, palpitations, diaphoresis, lightheadedness, or syncope increase concern for cardiac ischemia 1

Physical Examination Priorities

Cardiac Assessment

• Assess for diaphoresis, tachypnea, tachycardia, hypotension, pulmonary crackles, S3 gallop, or new mitral regurgitation murmur—all suggesting ACS 1
• Check for pulse differentials between extremities (suggests aortic dissection in 30% of cases) 1
• Auscultate for pericardial friction rub, which indicates pericarditis 1

Musculoskeletal Examination

• Palpate the costochondral joints for reproducible tenderness 1, 2
• However, 7% of patients with reproducible chest wall tenderness still have ACS, so this finding does not exclude cardiac pathology 3
• The absence of costochondritis on examination (as stated in this case) makes musculoskeletal causes less likely but does not eliminate them 2

Pulmonary Assessment

• Assess for unilateral absence of breath sounds (pneumothorax) or localized dullness with egophony (pneumonia) 1
• Tachycardia and dyspnea occur in >90% of pulmonary embolism cases 1

Diagnostic Algorithm

Step 1: Rule Out Life-Threatening Causes

1. ECG within 10 minutes to identify STEMI, NSTE-ACS patterns, or pericarditis 1
2. Cardiac troponin measurement immediately, with repeat at 6-12 hours 1
3. Chest radiograph to evaluate for pneumothorax, pneumonia, widened mediastinum (aortic dissection), or pleural effusion 1, 3

Step 2: Risk Stratification

• High-risk features requiring urgent intervention include: 1
  • Recurrent chest pain or dynamic ST-segment changes
  • Elevated troponin levels
  • Hemodynamic instability
  • Major arrhythmias (ventricular tachycardia, ventricular fibrillation)
  • Diabetes mellitus (which can present with atypical symptoms)

Step 3: Observation Period

• Multi-lead ECG ischemia monitoring for 6-12 hours 1
• Obtain 12-lead ECG during any recurrent chest pain episodes and compare with pain-free tracings 1
• Echocardiogram to assess left ventricular function and exclude other cardiovascular causes 1

Management Based on Findings

If Cardiac Workup is Positive

• Initiate aspirin 75-150 mg daily, clopidogrel (if indicated), low-molecular-weight heparin or unfractionated heparin, beta-blocker, and nitrates for persistent pain 1
• Arrange urgent cardiology consultation for potential cardiac catheterization 1

If Cardiac Workup is Negative

• Consider alternative diagnoses including pericarditis (sharp pain worse supine, better sitting forward, with friction rub) 1, 3
• Evaluate for pulmonary embolism using validated clinical decision rules and D-dimer if pretest probability is low-to-intermediate 3
• Consider gastrointestinal causes (esophageal spasm, gastroesophageal reflux disease) 1
• Reassess for atypical costochondritis despite initial negative examination, as symptoms may be intermittent 2, 4

Critical Pitfalls to Avoid

• Never use nitroglycerin response as a diagnostic criterion, as relief with nitroglycerin does not confirm or exclude myocardial ischemia (esophageal spasm also responds) 1, 3
• Do not assume sharp, pulsating pain excludes cardiac ischemia—13% of ACS patients present with pleuritic-type pain 3
• Never delay transfer to the emergency department for troponin testing if evaluating in an office setting—patients with suspected ACS should be transported urgently by EMS 1, 3
• Do not rely solely on the absence of costochondritis tenderness to exclude musculoskeletal causes, as pain may be intermittent or involve deeper structures 2, 4
• Remember that examination may be completely normal in uncomplicated acute myocardial infarction 1

Special Considerations for This Patient

Given the intermittent nature occurring at any time of day without clear triggers, the pulsating and sharp quality, and normal BMI:

• The lack of exertional component does not exclude ACS, as unstable angina occurs at rest or with minimal exertion 1
• The sharp, pulsating quality suggests but does not confirm a non-cardiac etiology 1
• Cardiac evaluation remains mandatory before attributing symptoms to benign causes 1, 5
• If cardiac workup is negative, consider rare causes such as coronary artery fistula (which can present with chronic intermittent chest pain misdiagnosed as costochondritis) 6 or rate-related left bundle branch block causing cardiac memory changes 7