In a 45-year-old man with one-day left-sided, non‑radiating chest pain reproducible on chest wall palpation, normal vital signs, and an ECG without significant ST‑segment or T‑wave abnormalities, what is the best approach to his ECG findings?

Best Approach to ECG Findings

In this patient with musculoskeletal chest pain (reproducible on palpation, movement-related, non-radiating) and a non-diagnostic ECG, the best approach is to perform serial ECGs if symptoms persist or change, obtain cardiac troponin levels to exclude acute coronary syndrome despite the low clinical suspicion, and consider discharge with outpatient follow-up if both remain normal. 1

Clinical Context and Risk Stratification

This patient presents with features that are noncardiac in origin based on the 2021 ACC/AHA chest pain guidelines 2:

• Pain characteristics favor musculoskeletal etiology:

  • Reproducible with chest wall palpation
  • Increases with movement
  • Non-radiating
  • No associated symptoms (nausea, dyspnea, diaphoresis)

• However, cardiac risk factors cannot be ignored:

  • 45-year-old male
  • 25 pack-year smoking history
  • Chest pain descriptors like "left-sided" have intermediate probability for ischemia 2

Algorithmic Approach to the Non-Diagnostic ECG

Step 1: Serial ECG Monitoring

When the initial ECG is non-diagnostic but clinical suspicion exists (even if low), serial ECGs should be performed to detect potential ischemic changes, especially if symptoms persist or clinical condition changes 1. This is a Class 1, Level C-EO recommendation.

• The ECG is diagnostic of acute MI in only 50% of patients at initial evaluation 3
• 1-4% of patients with completely normal ECGs ultimately have AMI 3
• Repeat ECGs every 15-30 minutes if symptoms continue

Step 2: Cardiac Biomarkers

Despite the musculoskeletal presentation, serial cardiac troponin (preferably high-sensitivity) should be measured 1:

• This is mandatory to exclude myocardial injury (Class 1, Level B-NR recommendation)
• High-sensitivity troponin enables more rapid detection or exclusion of myocardial injury 1
• The history alone, even when seemingly noncardiac, has limitations in excluding ACS 4

Step 3: Risk Stratification for Disposition

If both serial ECGs and troponins remain normal:

• This patient can be safely discharged with a negative predictive value approaching 99% for 30-day major adverse cardiac events
• However, clinical predictive models show that while long-term major events (death/MI) are well-predicted, short-term outcomes including need for revascularization are less well-predicted 4

Consider supplemental testing if:

• Posterior leads (V7-V9) are reasonable if posterior MI is suspected (Class 2a recommendation) 1
• Chest radiograph to evaluate other cardiac, pulmonary, or thoracic causes (Class 1 recommendation) 1

Critical Pitfalls to Avoid

1. Over-reliance on normal ECG: A normal or non-specifically abnormal ECG in a patient with classic anginal symptoms is dangerous 3. However, this patient's symptoms are not classic for angina.

2. Premature discharge without troponin: Even with obvious musculoskeletal features, troponin measurement is essential before discharge 1. Delayed transfer for diagnostic testing should be avoided (Class 3: Harm recommendation).

3. Missing subtle ECG findings: While this patient's ECG shows no ST-segment or T-wave abnormalities, be vigilant for:

   • Isolated T-wave inversion in aVL (can precede inferior MI) 5
   • ST depression in V1-V3 with tall R waves (posterior MI) 5
   • Diffuse ST depression with aVR elevation (left main disease) 5

Practical Management Algorithm

For this specific patient:

1. ✓ Obtain serial troponins (0 and 3 hours with high-sensitivity assay)

2. ✓ Repeat ECG if any symptom change

3. ✓ If both negative → discharge with:

   • Reassurance about musculoskeletal etiology
   • NSAIDs for pain management
   • Smoking cessation counseling (critical given 25 pack-year history)
   • Primary care follow-up within 1-2 weeks
   • Return precautions for any change in symptoms

4. ✗ Do NOT pursue stress testing or advanced cardiac imaging if troponins and serial ECGs remain normal with this presentation 4

The rhythm strip findings (not described in detail here) should be evaluated for any arrhythmias that would require arrhythmia-specific guideline management 1.