Differential Diagnoses for Chest Pain and Shortness of Breath

Life-Threatening Causes

The American College of Cardiology recommends immediate identification or exclusion of life-threatening causes such as acute coronary syndrome, aortic dissection, pulmonary embolism, tension pneumothorax, pericardial tamponade, and esophageal rupture in patients presenting with chest pain and shortness of breath 1
Acute coronary syndrome typically presents with retrosternal pressure, heaviness, or squeezing that builds gradually over minutes, radiating to the left arm, jaw, or neck, accompanied by diaphoresis, dyspnea, nausea, or syncope 1
The American Heart Association notes that pain occurs at rest or with minimal exertion and lasts longer than fleeting seconds in acute coronary syndrome 2, 1
Women and elderly patients with acute coronary syndrome frequently present with atypical symptoms, primarily dyspnea and nausea rather than classic chest pain 3, 4
High-risk populations, including those over 75 years old, with diabetes, renal insufficiency, or dementia, require immediate attention even with minimal symptoms 1
Aortic dissection presents with sudden-onset "ripping" or "tearing" chest pain radiating to the upper or lower back 5, 1
Physical exam findings for aortic dissection include pulse differentials between extremities, blood pressure differentials >20 mmHg, or new aortic regurgitation murmur 5, 1
The American College of Cardiology recommends CT angiography of the chest, abdomen, and pelvis as the diagnostic test of choice for aortic dissection 5
Pulmonary embolism presents with acute dyspnea and pleuritic chest pain 1
Physical findings for pulmonary embolism include tachycardia present in >90% of patients and tachypnea 1
The presence of risk factors such as immobility, recent surgery, malignancy, or hypercoagulable state is associated with pulmonary embolism 1
Tension pneumothorax presents with severe dyspnea and unilateral absence of breath sounds 1
Physical findings for tension pneumothorax include tracheal deviation, jugular venous distension, and hypotension 1
Pericardial tamponade presents with dyspnea, chest discomfort, and hypotension 5
The American College of Cardiology recommends transthoracic echocardiography (TTE) for immediate diagnosis of pericardial tamponade 5

Initial Management Algorithm

The American College of Cardiology recommends obtaining a 12-lead ECG within 10 minutes to evaluate for ST-segment changes, new Q waves, T-wave inversions, or new left bundle branch block 4
High-sensitivity cardiac troponin should be drawn immediately to establish biomarker diagnosis of acute MI 3, 4
The American Heart Association recommends using structured risk assessment with evidence-based diagnostic protocols to stratify patients into low, intermediate, or high risk 2, 3
Low-risk patients do not require urgent diagnostic testing for suspected CAD 2, 3
Intermediate-risk patients will benefit most from cardiac imaging and testing 2, 3
High-risk features during observation, such as recurrent ischemia, elevated troponin, or hemodynamic instability, require aggressive management 4

Disposition Decisions

The American College of Cardiology recommends immediate transfer to the ED by EMS if there is clinical evidence of ACS or other life-threatening causes, hemodynamic instability, or high-risk features present 1, 4
Consider observation unit or admission if the patient is at intermediate risk with abnormal initial workup, has recurrent symptoms during observation, or has elevated troponin levels 4, 1
Outpatient management is acceptable if the patient is at low risk by structured assessment, has a normal ECG and troponin, and no high-risk features 2, 3, 1

Acute Coronary Syndrome Diagnosis and Management

Critical Initial Actions

The American Heart Association recommends immediately measuring cardiac troponin as soon as possible and performing serial ECGs at 15-30 minute intervals during the first hour, as a normal initial ECG does not exclude acute coronary syndrome 6, 7, 8
Serial ECG monitoring is mandatory because up to 6% of patients with evolving ACS are discharged from the ED with a normal ECG, and a normal ECG may be associated with left circumflex or right coronary artery occlusions that are "electrically silent" 7, 8
Repeat ECG every 15-30 minutes during the first hour if symptoms persist or recur, especially if clinical suspicion for ACS remains intermediate-to-high 6, 7, 9
Consider supplemental leads V7-V9 to rule out posterior MI in patients with intermediate-to-high clinical suspicion 7, 9
Compare with previous ECGs if available to detect subtle new changes 7

Cardiac Biomarker Strategy

The American College of Cardiology recommends measuring cardiac troponin immediately upon presentation, then obtaining serial measurements at 3-6 hours after symptom onset using contemporary or high-sensitivity assays 8, 9, 10
If initial troponin is normal but ECG changes develop or clinical presentation suggests intermediate/high suspicion for ACS, obtain additional troponin levels beyond 6 hours 9
High-sensitivity cardiac troponin has >95% negative predictive value for MI when negative on admission, approaching 99% with high-sensitivity assays 9
A rising and/or falling pattern of troponin values is diagnostic for acute myocardial injury 9

Risk Stratification

Apply validated risk scores (TIMI or GRACE) to guide management intensity and disposition decisions 9

Evaluate for Alternative Life-Threatening Diagnoses

A normal ECG does not exclude other emergencies that present with chest pain and dyspnea 6
Aortic dissection: Assess for sudden-onset "ripping/tearing" pain radiating to back, pulse differentials between extremities, blood pressure differential >20 mmHg, or new aortic regurgitation murmur 6

Obtain Chest Radiography

Perform chest radiography to evaluate for cardiac, pulmonary, and thoracic causes, but do not delay urgent interventions if indicated 8
Chest x-ray can identify pneumonia, pneumothorax, rib fractures, pleural effusions, pulmonary artery enlargement, widened mediastinum (aortic dissection), or heart size/pulmonary congestion 8
Normal chest x-ray does not exclude PE or ACS 8

Physical Examination Priorities

Perform focused cardiovascular examination looking for specific findings that suggest serious pathology: 6, 10

Critical Pitfalls to Avoid

Do not rely on nitroglycerin response as diagnostic for myocardial ischemia—esophageal spasm and other conditions respond similarly 6
Do not delay transfer for office-based troponin testing when ACS is suspected—delayed transfer is harmful 7, 10
Do not base decisions solely on a single normal ECG—left ventricular hypertrophy, bundle branch blocks, and ventricular pacing may mask ischemia 7, 8

Special Population Considerations

Women are at risk for underdiagnosis and should be asked specifically about accompanying symptoms more common in women with ACS: nausea, fatigue, dyspnea, jaw pain, and epigastric discomfort 10
Older adults ≥75 years may present with atypical symptoms like isolated dyspnea, syncope, acute delirium, or unexplained falls without classic chest pain—maintain high suspicion for ACS 6, 10

Differential Diagnosis for Chest Pain and Shortness of Breath

Immediate Life-Threatening Differential Diagnoses

Aortic dissection is a critical contraindication to antithrombotic therapy and must be excluded before initiating treatment for suspected acute coronary syndrome, according to the European Heart Journal 11
The Aortic Dissection Detection (ADD) score assigns one point for any high-risk condition, high-risk pain feature, or high-risk examination feature; patients with a score >0 are considered at high-risk, as recommended by the European Heart Journal 11
High-risk examination features for aortic dissection include pulse deficit, systolic blood pressure limb differential >20 mmHg, focal neurologic deficit, new murmur of aortic regurgitation, or hypotension/shock, as stated in the European Heart Journal 11
The differential diagnosis for massive pulmonary embolism includes cardiogenic shock, tamponade, and aortic dissection, according to the European Heart Journal 12
Echocardiography showing indirect signs of acute pulmonary hypertension and right ventricular overload supports the diagnosis of pulmonary embolism in hemodynamically unstable patients, as recommended by the European Heart Journal 12

Risk Stratification Algorithm

Assess for orthostatic hypotension (decline >20 mmHg in SBP or >10 mmHg in DBP after 1 minute), as recommended by the Journal of the American College of Cardiology 13

Special Population Considerations

Hypertension is observed in 65-75% of individuals with aortic dissection, mostly poorly controlled, according to the European Heart Journal 14
In patients with aortic dissection, systolic blood pressure should be lowered to 100 mmHg if tolerated, as recommended by the journal Hypertension 15