USMLE/COMLEX 2 - Heart Murmurs

Here are key facts for USMLE Step 2 & COMLEX 2 from the Hypertension Overview tutorial, as well as points of interest at the end of this document that are not directly addressed in this tutorial but should help you prepare for the boards. See the tutorial notes for further details and relevant links.

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• Systolic murmurs: Aortic stenosis, Mitral regurgitation, Mitral valve prolapse
• Diastolic murmurs: Aortic regurgitation, Mitral stenosis
• Continuous murmur: Patent ductus arteriosus

• Harsh, crescendo-decrescendo systolic murmur at right upper sternal border, radiates to carotids
• Symptoms: Syncope, Angina, Dyspnea (SAD)
• Classic finding: Delayed, diminished carotid upstroke (pulsus parvus et tardus)
• Best initial test: Echocardiogram
• Definitive management: Valve replacement when symptomatic or EF <50%

• Holosystolic murmur at apex, radiates to axilla
• Causes: MVP, ischemic heart disease (papillary muscle rupture), endocarditis, rheumatic fever
• Symptoms: Dyspnea, fatigue, atrial fibrillation
• Management: ACE inhibitors, diuretics; surgery for severe symptomatic MR or LV dysfunction

• Mid-systolic click followed by late systolic murmur
• ↑ with Valsalva/standing, ↓ with squatting (due to reduced preload)
• Common in young women; may be benign or cause MR
• May require monitoring via echo

• Early diastolic decrescendo murmur at left sternal border
• Features: Wide pulse pressure, bounding pulses (Corrigan’s sign), head bobbing
• Causes: Infective endocarditis, aortic root dilation (Marfan), bicuspid aortic valve
• Management: Vasodilators (ACEi), surgical valve replacement if severe

• Opening snap + diastolic rumble, best at apex in left lateral decubitus
• ↑ with exercise or pregnancy
• Most common cause: Rheumatic fever
• Complications: Atrial fibrillation, pulmonary HTN
• Management: Diuretics, rate control (if AF), valve intervention if symptomatic or pulmonary HTN

• Squatting/leg raise: ↑ preload → ↑ most murmurs (except MVP, HOCM)
• Valsalva/standing: ↓ preload → ↑ MVP, ↑ HOCM, ↓ most other murmurs

• Elderly with exertional syncope and crescendo-decrescendo murmur → Aortic stenosis
• Young woman with mid-systolic click + murmur louder with Valsalva → MVP
• Migrant with pregnancy and murmur + LAE and dyspnea → Mitral stenosis
• Infective endocarditis + new murmur + pulmonary edema → Mitral or aortic regurgitation

• Auscultation is initial clue, but echocardiogram is confirmatory and defines severity
• TTE is typically sufficient; TEE if suspecting endocarditis or poor windows

• All chronic regurgitant lesions (MR, AR) → Volume overload → Eccentric hypertrophy
• Stenotic lesions (AS, MS) → Pressure overload → Concentric hypertrophy or atrial dilation

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• Vasodilators (ACEi/ARB, nifedipine) reduce afterload in regurgitant lesions
• Surgical referral for severe, symptomatic disease or when LV dysfunction occurs

• Pregnancy increases plasma volume → worsens MS symptoms
• Avoid volume overload; beta blockers to slow HR and prolong diastole

• Severe symptoms (NYHA Class III–IV)
• EF < 50% in asymptomatic AR or MR
• Severe stenosis with symptoms or valve area <1.0 cm² (AS, MS)

• Highest in patients with prosthetic valves, prior endocarditis, or congenital defects
• Mitral regurgitation and aortic regurgitation are common sites

• Systolic ejection murmur with radiation to carotids = AS
• Holosystolic murmur radiating to axilla = MR
• Decrescendo early diastolic murmur = AR
• Opening snap + mid-diastolic rumble = MS
• Mid-systolic click = MVP

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• Marfan + murmur + head bobbing → AR
• Young hypertensive female + murmur + BP discrepancy → Coarctation of aorta
• IV drug user + fever + new murmur → Tricuspid regurgitation from endocarditis

• MR/AR/MVP: follow with echo every 6–12 months if severe
• Mild cases: every 3–5 years
• Use TEE if endocarditis, prosthetic valve suspicion, or poor TTE quality

• Only for high-risk patients undergoing dental procedures:
• Prosthetic valves
• Prior infective endocarditis
• Certain congenital heart diseases