What should the initial workup include for a patient presenting with shortness of breath and mild to moderate chest pain?

Initial Workup for Shortness of Breath with Mild/Moderate Chest Pain

For a patient presenting with 5 days of shortness of breath and associated mild/moderate chest pain, obtain an ECG within 10 minutes, measure cardiac troponin immediately and repeat at 10-12 hours, perform a chest radiograph, and conduct a focused cardiovascular examination with attention to valvular disease, heart failure, and pulmonary disease. 1

Immediate Assessment (Within 10 Minutes)

Electrocardiogram

• Obtain a 12-lead ECG within 10 minutes of presentation to evaluate for ST-segment changes, new Q waves, T-wave inversions, or new left bundle branch block 1
• Compare with previous ECG if available, particularly valuable in patients with pre-existing cardiac pathology such as left ventricular hypertrophy 1
• Initiate continuous multi-lead ECG monitoring for arrhythmias and ST-segment changes 1

Focused History

• Document specific chest pain characteristics: nature (pressure, tightness, sharp, pleuritic), onset and duration, location and radiation, precipitating factors (exertion, rest), relieving factors, and associated symptoms 1
• Sharp chest pain that increases with inspiration and lying supine is unlikely ischemic and suggests pericarditis 1
• Pain reproducible by palpation, stabbing, pleuritic, or positional characteristics decrease likelihood of acute coronary syndrome (likelihood ratios 0.2-0.3) 2
• Assess cardiovascular risk factors including age, diabetes, prior myocardial infarction, and angina history, which increase probability of acute cardiac ischemia 1, 3

Physical Examination

• Perform focused cardiovascular examination specifically evaluating for valvular heart disease (aortic stenosis), hypertrophic cardiomyopathy, heart failure signs (rales, elevated jugular venous pressure), and pulmonary disease 1
• Presence of third heart sound (S3) gallop substantially increases probability of heart failure (positive likelihood ratio 11) 4
• Absence of rales decreases probability of heart failure (negative likelihood ratio 0.51) 4
• Document vital signs including blood pressure in both arms (to evaluate for aortic dissection) and pulse rate 3

Laboratory Assessment

Cardiac Biomarkers

• Draw cardiac troponin T or I immediately on admission as the preferred marker of myocardial damage 1
• Repeat troponin measurement at 10-12 hours after symptom onset for diagnosis of possible myocardial infarction and risk assessment 1
• Elevated troponin identifies high-risk patients requiring aggressive management 1

Additional Laboratory Tests

• Measure hemoglobin to detect anemia as a potential contributor 1
• Consider B-type natriuretic peptide (BNP) if heart failure is suspected; BNP <100 pg/mL effectively excludes heart failure (negative likelihood ratio 0.11) 4

Imaging Studies

Chest Radiograph

• Obtain chest radiograph as initial imaging study for all patients with dyspnea and chest pain 1
• Evaluate for pulmonary venous congestion (positive likelihood ratio 12.0 for heart failure), cardiomegaly (absence has negative likelihood ratio 0.33 for heart failure), pneumonia, pneumothorax, and pleural effusion 1, 4
• Chest radiograph provides diagnostic information in approximately one-third of chronic dyspnea cases when combined with laboratory evaluation 1

Risk Stratification During Observation Period

High-Risk Features Requiring Aggressive Management

• Recurrent ischemia (chest pain or dynamic ST-segment changes, particularly ST depression or transient ST elevation) 1
• Elevated troponin levels 1
• Hemodynamic instability (hypotension, pulmonary rales) during the 8-12 hour observation period 1
• Haemodynamic or rhythmic instability 1

Initial Medical Treatment for Suspected Acute Coronary Syndrome

• Administer aspirin 250-500 mg as soon as possible 1
• Initiate heparin (low-molecular-weight heparin can be started in emergency department) 1
• Give beta-blocker unless contraindicated 1
• Provide oral or intravenous nitrates for persistent or recurrent symptoms 1

Alternative Diagnoses to Consider

Pulmonary Causes

• Pulmonary embolism: Consider in patients with acute onset dyspnea; use clinical decision rules for risk stratification 5
• Pneumonia: Evaluate for fever, egophony, and dullness to percussion 5
• Pleurisy: Characterized by pain related to breathing movements 6
• Pneumothorax: Presents with acute chest pain and dyspnea 1, 6

Cardiovascular Non-Ischemic Causes

• Acute pericarditis: Sharp pain increased with inspiration and lying supine 1, 5
• Aortic dissection: Sudden onset ripping chest pain with radiation to back, evaluate for pulse differential 1, 5
• Heart failure: Assess for orthopnea, paroxysmal nocturnal dyspnea (positive likelihood ratio 2.6), and elevated BNP 4

Other Causes

• Gastroesophageal reflux disease: Burning retrosternal pain with acid regurgitation 5
• Chest wall pain/costochondritis: Localized pain reproducible by palpation 5
• Panic disorder/anxiety: Consider when cardiac and pulmonary causes excluded 5

Critical Pitfalls to Avoid

• Do not discharge patients without at least some diagnostic testing, as chest pain history alone cannot safely exclude acute coronary syndrome 2
• Normal ECG does not exclude acute coronary syndrome: 20% of acute myocardial infarction patients and 37% of unstable angina patients have normal initial ECGs 3
• Atypical presentations are common, particularly in older patients (>75 years), women, and those with diabetes 1, 7, 8
• Five-day duration of symptoms does not exclude acute coronary syndrome, as unstable angina can present with prolonged or recurrent symptoms 1
• Shortness of breath as chief complaint is less frequently associated with acute cardiac ischemia but does not exclude it, particularly in older patients and those with heart failure 3, 4