❤️ Aortic Stenosis: The Murmur with a Dangerous Delay
Aortic stenosis (AS) is a mechanical outflow obstruction that’s repeatedly tested on USMLE for its classic murmur, triad of symptoms, and surgical implications.
USMLE Tip: Think elderly + systolic murmur + syncope or angina = Aortic Stenosis.
🧬 Pathophysiology Review
Narrowed aortic valve → increased LV pressure → LV hypertrophy
↓ cardiac output with exertion
May lead to heart failure, arrhythmias, or sudden death
💡 Classic Clinical Triad
| Symptom | Mechanism |
|---|---|
| Syncope | Decreased perfusion with exertion |
| Angina | Increased oxygen demand from LVH |
| Dyspnea | Pulmonary congestion, reduced output |
🔎 Physical Exam Findings
| Finding | Description |
|---|---|
| Murmur | Crescendo-decrescendo systolic murmur at R 2nd ICS |
| Radiation | To carotids |
| Carotid upstroke | Delayed and diminished (pulsus parvus et tardus) |
| S2 | Soft or absent |
| Ejection click | Early systole if valve is mobile |
🩺 Etiologies by Age
| Age Group | Common Cause |
|---|---|
| < 70 years | Congenital bicuspid aortic valve |
| > 70 years | Senile calcific degeneration |
| Any age | Rheumatic heart disease |
🧪 Workup
| Test | Role |
|---|---|
| Echocardiography | Gold standard: valve area, pressure gradient |
| ECG | May show LVH |
| Chest X-ray | LVH, post-stenotic aortic dilation |
| Cardiac catheterization | Used pre-operatively or when echo is inconclusive |
💊 Treatment Approach
| Severity | Treatment |
|---|---|
| Mild/Moderate | Routine echo monitoring |
| Severe with symptoms | Surgical valve replacement (SAVR or TAVR) |
| Not surgical candidate | Balloon valvuloplasty (palliative) |
❌ Avoid vasodilators and diuretics in critical AS — they may ↓ preload dangerously!
📚 Sample USMLE Vignette
An 82-year-old male presents with syncope while walking. Exam reveals a late-peaking systolic murmur radiating to the carotids and diminished carotid pulses. Echo shows aortic valve area of 0.8 cm². What is the next step?
✅ Answer: Surgical aortic valve replacement
📲 Call to Action
🫀 Don’t let murmurs trip you up.
📲 Download the King of the Curve App for:
High-yield auscultation visuals
Heart sounds with quizzes
Step-style murmur vignettes
Daily leaderboard and Curve Coins
Frequently Asked Questions (FAQs)
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Aim for 4-6 focused hours, ensuring you incorporate breaks to avoid burnout.
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Practice mindfulness techniques, take practice exams under realistic conditions, and maintain a balanced lifestyle.
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Set short-term goals, seek support from mentors, and reward yourself for small achievements.
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Regular exercise improves focus, reduces stress, and enhances overall mental clarity.
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KOTC offers personalized learning tools, gamification features, and adaptive question banks to help students stay on track without burnout.
