What is the best course of action for a patient presenting with sternum discomfort and tenderness?

Management of Sternum Discomfort and Tenderness

Obtain an ECG immediately in your office and interpret it within 10 minutes; if this cannot be done or if any ischemic changes are present, transfer the patient to the emergency department by EMS for cardiac troponin testing—do not delay transfer for office-based troponin testing. 1, 2

Immediate Actions in Office Setting

• Perform a 12-lead ECG within 10 minutes of patient presentation, regardless of whether symptoms suggest cardiac or musculoskeletal origin 1
• If ECG equipment is unavailable or interpretation cannot occur within 10 minutes, immediately refer the patient to the ED 1
• Never delay transfer to obtain troponin levels in the office setting—this causes harmful delays in diagnosis and treatment 1, 2
• Transport by personal automobile should be avoided; use EMS for transfer 1

Physical Examination Findings to Guide Diagnosis

Cardiac Causes to Rule Out First

• Acute coronary syndrome: Look for diaphoresis, tachypnea, tachycardia, hypotension, crackles, S3 gallop, or new mitral regurgitation murmur (though examination may be completely normal in uncomplicated cases) 1
• Pericarditis: Fever, pleuritic chest pain that worsens when supine, and friction rub on auscultation 1
• Myocarditis: Fever, chest pain, signs of heart failure, and S3 gallop 1
• Aortic dissection: Pulse differential between extremities (present in 30% of patients), connective tissue disorder features, severe abrupt-onset pain 1

Musculoskeletal Causes (Most Common)

• Costochondritis/Tietze syndrome: Tenderness to palpation of the costochondral joints is the hallmark finding 1
• Pain that is reproducible with chest wall palpation, varies with body position, breathing, turning, twisting, or bending 2, 3
• Well-localized pain on the chest wall that can be pointed to with one finger 2

ECG-Based Management Algorithm

If ECG Shows ST-Elevation or New ST Depression or New LBBB

• Immediate EMS transfer to ED for STEMI/NSTE-ACS protocol 1, 2
• Administer aspirin 250-500 mg immediately if not contraindicated 2
• Consider sublingual nitroglycerin if no bradycardia or hypotension present 2, 4

If ECG is Nondiagnostic but Symptoms Persist

• Perform serial ECGs at 15-30 minute intervals to detect evolving ischemic changes 1
• Consider supplemental leads V7-V9 if intermediate-to-high clinical suspicion for posterior MI 1
• Transfer to ED for cardiac troponin measurement as soon as possible 1

If ECG is Normal and Clinical Suspicion is Low

• Cardiac biomarkers should still be measured if any cardiac risk factors are present 1
• If initial troponin is negative within 6 hours of symptom onset, repeat measurement at 8-12 hours after symptom onset 1

Key Historical Features That Distinguish Cardiac from Non-Cardiac Pain

Features Suggesting Cardiac Origin

• Pain that interrupts normal daily activities 2
• Associated cold sweats, nausea, vomiting, or anxiety/fear 2
• Radiation pattern typical of angina (to jaw, left arm, back) 2
• Exertional component or relief with rest 2

Features Suggesting Non-Cardiac Origin

• Pain that varies with respiration, body position, or food intake 2
• Pain reproduced by palpation of the chest wall 2, 3
• Pain generated from multiple sites 2
• Sharp, stabbing quality that is fleeting (seconds duration) 1

Critical Pitfalls to Avoid

• Do not assume chronicity equals safety: Stable angina can progress to acute coronary syndrome even with weeks of symptoms 2
• Do not rely on physical examination alone: Physical exam contributes almost nothing to diagnosing myocardial infarction unless shock is present 2
• Do not use chest wall tenderness to exclude cardiac disease: While tenderness suggests musculoskeletal cause, it does not definitively rule out concurrent cardiac pathology 1, 2
• Do not delay cardiac workup based solely on age: Use age and sex to guide threshold, but younger patients can still have ACS 2

When Musculoskeletal Diagnosis is Appropriate

Only after cardiac causes have been systematically excluded with ECG and appropriate risk stratification can you confidently diagnose costochondritis or other musculoskeletal causes 2. The presence of reproducible chest wall tenderness at the costochondral joints strongly suggests musculoskeletal etiology, but this finding alone is insufficient to exclude cardiac disease without proper cardiac evaluation 1, 3.