Internal Medicine · Year 3 · from Internal Medicine
Case 2: Aortic Dissection
Patient Presentation
A 67-year-old man with a history of long-standing poorly controlled hypertension presents with sudden-onset severe chest pain that began 45 minutes ago. He describes the pain as "tearing" in quality, starting in his anterior chest and radiating to his back between his shoulder blades. The pain was maximal at onset. He denies shortness of breath or diaphoresis.
Vital Signs
- Blood Pressure: Right arm 185/110 mmHg, Left arm 145/85 mmHg
- Heart Rate: 88 bpm
- Respiratory Rate: 18/min
- Oxygen Saturation: 97% on room air
Physical Examination
- General: In significant distress due to pain
- Cardiovascular: Regular rhythm, new early diastolic murmur at left sternal border
- Pulmonary: Clear to auscultation
- Neurological: No focal deficits
- Extremities: Blood pressure differential >20 mmHg between arms
Initial Workup
- ECG: Normal sinus rhythm, no ST-T changes
- Troponin I: <0.04 ng/mL (normal)
- D-dimer: 2,450 ng/mL (normal <500 ng/mL)
- Chest X-ray: Widened mediastinum
Questions
- What is the most likely diagnosis?
- A) Acute coronary syndrome
- B) Pulmonary embolism
- C) Aortic dissection
- D) Pericarditis
- What is the most appropriate next diagnostic test?
- A) Stress testing
- B) CT angiography of the chest
- C) Transthoracic echocardiography
- D) Coronary angiography
- What is the significance of the new diastolic murmur?
- What is the initial blood pressure management goal?
- What classification system is used for aortic dissection, and how would this patient be classified?
Answers
- C) Aortic dissection - The classic presentation includes sudden-onset severe tearing/ripping chest pain radiating to the back, maximal at onset, blood pressure differential between arms, widened mediastinum on chest X-ray, and new aortic regurgitation murmur.
- B) CT angiography of the chest - CTA is the imaging modality of choice for suspected aortic dissection, with sensitivity and specificity >95%. It provides detailed anatomic information about the extent of dissection.
- Significance of diastolic murmur: The new early diastolic murmur indicates aortic regurgitation, which occurs when the dissection extends proximally to involve the aortic root and disrupts the aortic valve apparatus. This is a concerning finding that may indicate need for surgical repair.
- Blood pressure management goal:
- Target systolic BP: 100-120 mmHg
- Target heart rate: <60 bpm
- First-line agents: IV beta-blockers (esmolol, labetalol)
- Add vasodilators (nitroprusside) if needed after beta-blockade
- Beta-blockers must be given before vasodilators to prevent reflex tachycardia
- Classification systems:
- Stanford Classification:
- Type A: Involves ascending aorta (requires emergent surgery)
- Type B: Involves descending aorta only (usually medical management)
- DeBakey Classification:
- Type I: Originates in ascending, propagates distally
- Type II: Confined to ascending aorta
- Type III: Originates in descending aorta
This patient likely has a Stanford Type A dissection given the involvement of the aortic root (evidenced by aortic regurgitation), requiring emergent surgical consultation.
Learning Points
- Chest pain risk stratification requires systematic evaluation using history, physical examination, ECG, and cardiac biomarkers.
- STEMI management emphasizes rapid reperfusion with door-to-balloon time <90 minutes for PCI.
- Aortic dissection should be suspected with tearing chest pain, blood pressure differential, and widened mediastinum.
- The HEART score helps risk-stratify patients with chest pain for appropriate disposition.
- Life-threatening causes of chest pain (ACS, aortic dissection, pulmonary embolism, tension pneumothorax, esophageal rupture) must be rapidly identified and treated.