What is the most likely diagnosis for a patient in their late 60s with sudden onset severe pressure-like chest pain radiating to the shoulders, associated with nausea, and a history of hypertension and type 2 diabetes?

Most Likely Diagnosis: Aortic Dissection

This patient's presentation is classic for acute aortic dissection, which must be the primary diagnostic consideration and warrants immediate imaging with CT angiography. The combination of sudden-onset severe pressure-like pain radiating to bilateral shoulders, associated nausea, hypertension, diabetes, and male sex in the late 60s creates a high-risk profile that matches the typical aortic dissection patient described in multiple guidelines 1.

Why Aortic Dissection is Most Likely

Patient Demographics Match Perfectly

• The typical aortic dissection patient is a male in his 60s with hypertension presenting with abrupt onset chest pain 1
• This patient has hypertension (blood pressure 150/95) and type 2 diabetes, both major risk factors 1
• Hypertension is present in 65-75% of aortic dissection cases and is often poorly controlled 1

Pain Characteristics Are Highly Specific

• Pain of abrupt onset with maximum intensity at onset is present in up to 90% of aortic dissection patients 1
• The sudden onset while watching TV (at rest) is characteristic—dissection pain reaches peak severity immediately, unlike myocardial infarction where pain builds gradually 1
• Bilateral shoulder pain represents the radiation pattern consistent with proximal dissection 1
• The pressure-like quality, while often described as "tearing" or "ripping," can present as severe pressure 1

Physical Examination Findings Support Dissection

• Blood pressure of 150/95 is consistent with distal aortic dissection, which typically presents with hypertension 1
• Normal radial pulses bilaterally do not exclude dissection—pulse deficits occur but are not universal 1
• Absence of murmur does not exclude dissection, though aortic regurgitation occurs in 40-75% of Type A dissections 1

Why Other Diagnoses Are Less Likely

ST-Elevation Myocardial Infarction (STEMI)

• Myocardial infarction pain typically starts slowly and gains intensity over time, described as oppressive and dull rather than sudden-onset 1
• The abrupt onset with maximum severity immediately is atypical for MI 1
• Bilateral shoulder radiation is unusual for typical MI presentation 2
• However, aortic dissection can cause STEMI by involving coronary arteries (particularly right coronary artery), making this a critical differential 1

Acute Pericarditis

• Pericarditis pain typically changes with position and breathing 1
• This patient's pain does NOT change with position or breathing, making pericarditis unlikely 1
• Pericarditis usually presents with pleuritic chest pain and a friction rub on examination 1

Myocarditis

• Myocarditis typically presents more gradually with preceding viral symptoms 1
• The sudden onset while at rest is atypical for myocarditis
• Myocarditis does not typically present with severe bilateral shoulder pain

Critical Immediate Management Algorithm

Step 1: Immediate Diagnostic Testing

• Obtain ECG immediately to exclude STEMI, but do not let a normal ECG delay CT angiography if dissection is suspected 1
• Order CT angiography of chest, abdomen, and pelvis immediately—this is the diagnostic test of choice for stable patients with suspected dissection 1
• Check D-dimer if available, though levels below 500 ng/mL make dissection unlikely 1
• Do NOT wait for cardiac enzymes to return before proceeding with imaging 1

Step 2: Immediate Medical Management (While Awaiting Imaging)

• Reduce systolic blood pressure below 120 mmHg and heart rate ≤60 bpm to decrease aortic wall stress 1
• Administer intravenous labetalol as first-line agent (combined alpha- and beta-blocking properties) 1
• Place arterial line for invasive blood pressure monitoring 1
• Transfer to intensive care unit or aorta team center 1

Step 3: Risk Stratification Using ADD-RS

The 2024 ESC guidelines recommend using the Aortic Dissection Detection-Risk Score combined with D-dimer 1:

• High-risk conditions: Known aortic disease, Marfan syndrome, recent aortic manipulation 1
• High-risk pain features: Abrupt onset, severe intensity, ripping/tearing quality 1
• High-risk exam features: Pulse deficit, blood pressure differential >20 mmHg between limbs, focal neurologic deficit, new aortic regurgitation murmur 1

Critical Pitfalls to Avoid

Do Not Assume Normal Findings Exclude Dissection

• Up to 6.4% of acute dissection patients present without pain 1
• Normal radial pulses do not exclude dissection 1
• Absence of widened mediastinum on chest X-ray does not exclude dissection 3

Do Not Delay Imaging for Cardiac Enzyme Results

• Cardiac enzymes should be obtained but awaiting results must not delay imaging if dissection probability is high 1
• Troponin can be elevated in dissection due to coronary involvement 4

Recognize That Dissection Can Mimic ACS

• Aortic dissection involving coronary ostia can cause true STEMI on ECG 1, 4
• Before proceeding to cardiac catheterization for presumed STEMI, consider bedside echocardiography if any atypical features suggest dissection 4
• The differential diagnosis explicitly includes "acute coronary syndrome with and without ST-elevation" 1

Mortality Considerations

• Untreated acute Type A dissection has mortality of 1-2% per hour 5, 6
• 30-day mortality for all acute aortic dissection ranges from 23-55.8% 1
• With successful surgical treatment of Type A dissection, 5-year survival increases to 75% 6

The stakes are too high to miss this diagnosis—when clinical features suggest aortic dissection in a high-risk patient, proceed immediately to CT angiography while initiating blood pressure and heart rate control.