What is the differential diagnosis for an adult patient with a history of hypertension and cardiovascular risk factors presenting with a positive empty cab test, chest pain, and shortness of breath?

Differential Diagnosis for Positive Empty Can Test

A positive empty can test (Jobe test) indicates supraspinous tendon pathology in the shoulder and is not related to chest pain, shortness of breath, or cardiovascular emergencies—this appears to be a misunderstanding of terminology, as the clinical context describes life-threatening cardiopulmonary conditions that require immediate evaluation for acute coronary syndrome, aortic dissection, and pulmonary embolism.

Immediate Life-Threatening Differential Diagnoses

Given the clinical context of chest pain and shortness of breath in a patient with hypertension and cardiovascular risk factors, the following conditions must be excluded immediately:

Acute Coronary Syndrome (ACS)

• Obtain a 12-lead ECG within 10 minutes and measure high-sensitivity cardiac troponin immediately upon presentation 1.
• ACS 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.
• Pain occurs at rest or with minimal exertion and lasts longer than fleeting seconds 1.
• Repeat ECG every 15-30 minutes during the first hour if symptoms persist, as up to 6% of patients with evolving ACS are discharged with a normal initial ECG 1.
• Serial troponin measurements at 3-6 hours after symptom onset are mandatory, with high-sensitivity assays having >95% negative predictive value when negative on admission 1.

Aortic Dissection

• Aortic dissection is a critical contraindication to antithrombotic therapy and must be excluded before initiating treatment for suspected ACS 2.
• The typical presentation includes abrupt onset (84% of cases) of severe chest pain (90% of cases) described as sharp or stabbing (51-64%), though the classic "tearing" or "ripping" quality is less common 3.
• Type A dissections present with anterior chest pain (71%), while Type B dissections present with interscapular back pain (64%) 3.
• High-risk examination features include pulse deficit, systolic blood pressure limb differential >20 mmHg, focal neurologic deficit, new murmur of aortic regurgitation, or hypotension/shock 2, 3.
• High-risk conditions include Marfan syndrome, other connective tissue disorders, family history of aortic disease, known aortic valve disease, recent aortic manipulation, or known thoracic aortic aneurysm 2, 3.
• 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 (sensitivity 91%) 2.
• Proceed directly to CT angiography of the chest, abdomen, and pelvis if clinical suspicion persists, even with an ADD score of 0 3.
• Up to 6.4% of patients with acute aortic dissection present without pain, particularly older patients, those on steroids, and patients with Marfan syndrome 3.

Pulmonary Embolism (PE)

• PE presents with acute dyspnea and pleuritic chest pain 1.
• Tachycardia is present in >90% of patients, and tachypnea is common 1.
• Risk factors include immobility, recent surgery, malignancy, or hypercoagulable state 1.
• The differential diagnosis for massive PE includes cardiogenic shock, tamponade, and aortic dissection 2.
• Echocardiography showing indirect signs of acute pulmonary hypertension and right ventricular overload supports the diagnosis in hemodynamically unstable patients 2.

Pericardial Tamponade

• Presents with dyspnea, chest discomfort, and hypotension 1.
• Transthoracic echocardiography (TTE) is recommended for immediate diagnosis 1.

Tension Pneumothorax

• Presents with severe dyspnea and unilateral absence of breath sounds 1.
• Physical findings include tracheal deviation, jugular venous distension, and hypotension 1.

Risk Stratification Algorithm

Step 1: Immediate Assessment

• Obtain vital signs, including blood pressure in both arms to detect differentials >20 mmHg suggestive of aortic dissection 3.
• Perform 12-lead ECG within 10 minutes 1.
• Draw high-sensitivity cardiac troponin immediately 1.
• Assess for orthostatic hypotension (decline >20 mmHg in SBP or >10 mmHg in DBP after 1 minute) 2.

Step 2: Calculate ADD Score for Aortic Dissection Risk

• Assign one point for presence of any high-risk condition, high-risk pain feature, or high-risk examination feature 2.
• ADD score 0: 4.3-5.9% risk of dissection 3.
• ADD score 1: 27.3% risk of dissection 3.
• ADD score ≥2: 39.1% risk of dissection 3.
• Do not rely solely on ADD score to exclude dissection; even patients with ADD score 0 require CT angiography if clinical suspicion persists 3.

Step 3: Evaluate Cardiac Biomarkers and ECG

• A rising and/or falling pattern of troponin values is diagnostic for acute myocardial injury 1.
• If initial troponin is normal but ECG changes develop or clinical suspicion remains intermediate/high, obtain additional troponin levels beyond 6 hours 1.
• Apply validated risk scores (TIMI or GRACE) to guide management intensity 1.

Step 4: Obtain Chest Radiography

• Perform chest X-ray to evaluate for pneumothorax, pleural effusions, pulmonary artery enlargement, or widened mediastinum 1.
• Normal chest X-ray does not exclude PE or ACS, and mediastinal widening is present in only 62.6% of Type A and 56% of Type B dissections 3.

Special Population Considerations

Hypertensive Patients

• Hypertension is observed in 65-75% of individuals with aortic dissection, mostly poorly controlled 2.
• Hypertension is typically associated with distal (Type B) aortic dissection 2.
• In patients with aortic dissection, systolic blood pressure should be lowered to 100 mmHg if tolerated 2.

Women and Elderly Patients

• Women and elderly patients with ACS frequently present with atypical symptoms, primarily dyspnea and nausea rather than classic chest pain 1.
• Women with aortic dissection are older at presentation, less likely to present within 6 hours, and have higher in-hospital mortality (30% vs 21% in men) 3.
• Older adults ≥75 years may present with isolated dyspnea, syncope, acute delirium, or unexplained falls without classic chest pain 1.

Critical Pitfalls to Avoid

• Do not initiate antithrombotic therapy until aortic dissection is excluded, as it is a contraindication 2.
• Do not rely on nitroglycerin response as diagnostic for myocardial ischemia—esophageal spasm and other conditions respond similarly 1, 4.
• Do not base decisions solely on a single normal ECG—left ventricular hypertrophy, bundle branch blocks, and ventricular pacing may mask ischemia 1.
• Do not use D-dimer alone to rule out aortic dissection; false-negative results occur in chronic dissections, thrombosed false lumen, intramural hematoma without intimal flap, or young patients 3.
• Do not dismiss chest pain in women or elderly patients, as they frequently present with atypical symptoms 1, 4.

Disposition Decisions

Immediate Transfer to Emergency Department

• Clinical evidence of ACS or other life-threatening causes 1.
• Hemodynamic instability 1.
• High-risk features present (ADD score >0, pulse deficits, blood pressure differentials) 2, 3.

Observation Unit or Admission

• Intermediate risk with abnormal initial workup 1.
• Recurrent symptoms during observation 1.
• Elevated troponin levels 1.

Outpatient Management

• Low risk by structured assessment 1.
• Normal ECG and troponin 1.
• No high-risk features 1.