What are the initial diagnostic steps for a patient admitted with chest pain?

Initial Diagnostic Workup for Chest Pain in Admitted Ward Patients

For any patient admitted to the ward with chest pain, immediately obtain a 12-lead ECG (within 10 minutes), measure high-sensitivity cardiac troponin as soon as possible, and obtain a chest radiograph to evaluate cardiac, pulmonary, and thoracic causes. 1, 2

Immediate ECG Evaluation (Within 10 Minutes)

• Acquire and interpret a 12-lead ECG within 10 minutes of patient arrival to the ward, regardless of whether the patient appears stable 1, 2
• If ST-segment elevation, new ST-depression, or new left bundle branch block is present, immediately activate STEMI or NSTE-ACS protocols 1, 2
• A single normal ECG never rules out acute coronary syndrome (ACS) - up to 6% of patients with evolving ACS can have a normal initial ECG 3
• Perform serial ECGs if the initial tracing is nondiagnostic, especially when clinical suspicion remains high, symptoms persist, or the patient's condition deteriorates 1, 3, 2
• Consider supplemental posterior leads (V7-V9) in patients with intermediate-to-high ACS suspicion and nondiagnostic standard ECG, as left circumflex or right coronary artery occlusions causing posterior wall ischemia are often "electrically silent" on standard 12-lead ECG 1, 3, 2
• Compare the current ECG with previous ECGs when available, as left ventricular hypertrophy, bundle branch blocks, and ventricular pacing may mask signs of ischemia 3, 2

Cardiac Biomarker Testing

• Measure cardiac troponin (cTn I or T) as soon as possible after the patient arrives on the ward 1, 2
• High-sensitivity troponin is the preferred biomarker because it enables more rapid detection or exclusion of myocardial injury and increases diagnostic accuracy 3, 2
• Repeat troponin measurements at 1-3 hours for high-sensitivity troponin assays and 3-6 hours for conventional troponin assays after initial collection 2
• For patients with acute chest pain, normal ECG, and symptoms beginning at least 3 hours before arrival, a single high-sensitivity troponin below the limit of detection at time zero is reasonable to exclude myocardial injury 2
• Serial troponin measurements are necessary to identify abnormal values and rising/falling patterns 3
• Do not use creatine kinase-MB isoenzyme or myoglobin for diagnosis when troponin is available 3

Chest Radiography

• Obtain a chest X-ray to evaluate for alternative cardiac, pulmonary, and thoracic causes including pneumonia, pneumothorax, widened mediastinum (suggesting aortic dissection), heart failure, and pleural effusion 1, 2

Risk Stratification After Initial Testing

• Implement a clinical decision pathway that categorizes patients into low-, intermediate-, and high-risk strata to facilitate subsequent diagnostic evaluation 1, 2
• Patients with acute chest pain and <1% 30-day risk of death or major adverse cardiovascular events (MACE) should be designated as low risk 2
• High-risk features include recurrent ischemia, elevated troponin levels, hemodynamic instability, major arrhythmias, and diabetes mellitus 3

Additional Diagnostic Testing Based on Risk

• For intermediate-risk patients, transthoracic echocardiography (TTE) is recommended as a rapid bedside test to establish baseline ventricular and valvular function, evaluate for wall motion abnormalities, and assess for pericardial effusion 2
• For high-risk patients, consider invasive coronary angiography 3
• For intermediate-risk patients, perform anatomic or functional testing such as coronary CT angiography 3

Symptom-Driven Repeat Testing

• Repeat ECG immediately when chest pain recurs or persists during ward evaluation, as ongoing symptoms increase the likelihood of capturing evolving ischemic changes 1, 3
• Repeat ECG if the clinical condition deteriorates, including development of dyspnea, diaphoresis, hemodynamic instability, or arrhythmias 3
• Continue serial ECGs until other diagnostic testing (troponins, imaging) definitively rules out ACS 3
• When clinical suspicion for ACS remains intermediate-to-high, perform serial ECGs even if symptoms have temporarily abated 3

Critical Pitfalls to Avoid

• Never rely on a single normal ECG to exclude ACS in a patient with ongoing chest pain or high clinical suspicion - this is the most dangerous error in chest pain evaluation 3
• Do not delay repeat ECGs waiting for scheduled intervals if symptoms change; symptom-driven timing takes priority 3
• Relief with nitroglycerin is not diagnostic of myocardial ischemia and should not be used as a diagnostic criterion 1