Murmur questions are the ultimate “details matter” trap: one missed clue (timing, radiation, maneuvers, pulse pressure) and you’ll confidently pick the wrong valve. The good news is that Step-style vignettes are predictable—if you train yourself to extract murmur characteristics first, then use maneuvers to confirm, you’ll start seeing answer choices as a set of deliberate contrasts rather than random heart sounds.
Tag: Cardiovascular > Valvular Heart Disease
The Clinical Vignette (Q-Bank Style)
A 72-year-old man comes to clinic for progressive exertional dyspnea and occasional chest pressure. He has a history of long-standing hypertension. On exam, BP is 138/82 mm Hg, HR 78/min. Carotid upstrokes are delayed. Cardiac auscultation reveals a harsh crescendo–decrescendo systolic murmur best heard at the right upper sternal border with radiation to the carotids. The murmur is louder with squatting and softer with Valsalva.
Which valvular abnormality is most likely present?
A. Aortic stenosis due to calcific degeneration
B. Mitral regurgitation due to papillary muscle dysfunction
C. Hypertrophic obstructive cardiomyopathy due to septal hypertrophy
D. Aortic regurgitation due to aortic root dilation
E. Mitral stenosis due to rheumatic heart disease
Stepwise Approach: Identify the Murmur Like a Pro
Before you even look at choices, lock in these 4 features:
- Timing: systolic ejection (crescendo–decrescendo)
- Location: right upper sternal border (RUSB)
- Radiation: to carotids
- Maneuvers: louder with ↑ preload/afterload (squat), softer with ↓ preload (Valsalva)
Add the extra clue: delayed carotid upstroke (pulsus parvus et tardus).
That combo is basically a fingerprint for aortic stenosis.
Correct Answer: A. Aortic stenosis due to calcific degeneration
Why it’s correct
This is classic degenerative (calcific) aortic stenosis in an older adult.
High-yield clinical features
- Harsh systolic crescendo–decrescendo murmur at RUSB
- Radiates to carotids
- Pulsus parvus et tardus (weak, delayed carotid pulse)
- May have soft/absent A2 (advanced disease)
- Symptoms: SAD
- Syncope (exertional)
- Angina
- Dyspnea/heart failure
Maneuvers (money for Step)
Aortic stenosis gets louder when you increase flow across the valve:
- Squatting → ↑ venous return (preload) + ↑ SVR → louder
- Valsalva/standing → ↓ preload → softer
- Handgrip (↑ afterload) often decreases AS intensity (more blood regurgitates across MR/AR; forward flow across stenotic aortic valve may fall). On exams, the more consistent discriminator is HCM increases with handgrip? (No—HCM typically decreases with handgrip.)
Pathophysiology tie-in
Calcific degeneration leads to a fixed obstruction, so cardiac output can’t rise appropriately with exercise → exertional symptoms.
Distractor Breakdown: Why Every Wrong Choice Is Wrong
B. Mitral regurgitation due to papillary muscle dysfunction
Why you might pick it: systolic murmur and dyspnea.
Why it’s wrong here
- MR is typically holosystolic (uniform intensity), not crescendo–decrescendo.
- Best heard at the apex, not RUSB.
- Radiates to the axilla, not the carotids.
- Often increases with handgrip (↑ afterload → more regurg).
When MR would be right
- Post-MI patient with new holosystolic murmur (papillary muscle dysfunction/rupture)
- Murmur loudest at apex + pulmonary edema
C. Hypertrophic obstructive cardiomyopathy (HOCM) due to septal hypertrophy
Why you might pick it: also a systolic crescendo–decrescendo murmur.
Why it’s wrong here
- HOCM murmur is best heard at the left lower sternal border (LLSB), not RUSB.
- Does not radiate to carotids in the classic way AS does.
- Maneuvers go the opposite direction:
- Valsalva/standing (↓ preload) → louder (smaller LV cavity worsens obstruction)
- Squatting (↑ preload/afterload) → softer
- Carotid findings: may show spike-and-dome; AS gives parvus et tardus.
High-yield pearl
- If the question emphasizes familial, young athlete, syncope with exertion, and murmur that increases with Valsalva, think HOCM.
D. Aortic regurgitation due to aortic root dilation
Why you might pick it: aortic valve pathology, older adult.
Why it’s wrong here
- AR is a diastolic murmur: high-pitched blowing early diastolic decrescendo.
- Best heard along left sternal border with patient leaning forward at end-expiration.
- Classic associated findings:
- Wide pulse pressure
- Bounding pulses (e.g., Corrigan pulse)
- Head bobbing (de Musset), nail bed pulsations (Quincke)
Associated etiologies to know
- Aortic root dilation (Marfan, syphilitic aortitis, ankylosing spondylitis)
- Infective endocarditis
- Bicuspid aortic valve
E. Mitral stenosis due to rheumatic heart disease
Why you might pick it: older patient + exertional dyspnea.
Why it’s wrong here
- MS is diastolic: opening snap followed by low-pitched rumbling diastolic murmur.
- Heard best at the apex with patient in left lateral decubitus.
- Often associated with:
- Atrial fibrillation (left atrial enlargement)
- Hemoptysis, hoarseness (Ortner syndrome), pulmonary HTN
Classic Step association
- Rheumatic fever history (often immigrant or developing-world context; can present years later).
Rapid Comparison Table (Exam-Speed)
| Lesion | Timing/Quality | Best Heard | Radiation | Key Maneuvers | Classic Extra Clue |
|---|---|---|---|---|---|
| Aortic stenosis | Systolic crescendo–decrescendo | RUSB | Carotids | ↑ with squat, ↓ with Valsalva | Pulsus parvus et tardus, syncope/angina/dyspnea |
| HOCM | Systolic crescendo–decrescendo | LLSB | Minimal | ↑ with Valsalva/standing, ↓ with squat/handgrip | Young, familial; sudden death risk |
| Mitral regurg | Holosystolic blowing | Apex | Axilla | ↑ with handgrip | Post-MI papillary dysfunction; LA dilation |
| Aortic regurg | Early diastolic decrescendo | LSB | — | ↑ with handgrip (often) | Wide pulse pressure, bounding pulses |
| Mitral stenosis | Diastolic rumble + opening snap | Apex | — | Louder with exercise (↑ flow) | AF, rheumatic disease |
High-Yield Takeaways (What Step Wants You to Do)
- Start with timing (systolic ejection vs holosystolic vs diastolic).
- Use location + radiation to narrow to 1–2 choices fast.
- Confirm with maneuvers:
- HOCM: louder with less preload (Valsalva/standing)
- AS: louder with more preload (squatting)
- MR/AR: louder with handgrip (↑ afterload → more regurg)
- Don’t ignore peripheral pulse clues:
- AS: parvus et tardus
- AR: wide pulse pressure, bounding pulses