How can I auscultate the heart to identify valvular lesions?

Auscultation of Valvular Heart Disease: A Systematic Approach

Core Auscultation Technique

Master the timing, location, radiation, and dynamic maneuvers of cardiac murmurs to accurately identify valvular lesions at the bedside. 1

Essential Auscultation Sites and Findings

Identify the maximal intensity location for each valve lesion:

• Aortic stenosis: 2nd right intercostal space (RIS), radiates to neck/carotids 1
• Aortic regurgitation: 2nd-4th left intercostal space (LIS) at sternal border 1
• Mitral stenosis: Apex, best heard in left lateral decubitus position 1
• Mitral regurgitation: Apex, radiates to axilla 1
• Hypertrophic cardiomyopathy: 4th LIS at left sternal border 1

Critical Timing Classification

Categorize murmurs by their timing in the cardiac cycle, as this determines your diagnostic pathway:

• Diastolic murmurs: Always pathologic—require immediate echocardiography 1
• Continuous murmurs: Pathologic (except cervical venous hum or mammary souffle in pregnancy)—require echocardiography 1
• Holosystolic murmurs: Indicate mitral regurgitation, tricuspid regurgitation, or ventricular septal defect—require echocardiography 1
• Late systolic murmurs: Suggest mitral valve prolapse—require echocardiography 1
• Midsystolic murmurs: May be innocent (grade ≤2 in young asymptomatic patients) or pathologic (grade ≥3, or any grade with abnormal features) 1

Dynamic Auscultation Maneuvers

Use physiologic maneuvers to differentiate valve lesions—this is the key to bedside diagnosis.

Standing Maneuver

• Decreases left ventricular volume, causing earlier prolapse in systole 2
• Mitral valve prolapse: Murmur becomes longer and louder 2
• Hypertrophic cardiomyopathy: Murmur becomes louder 1, 3
• Most other murmurs: Become softer 1

Squatting Maneuver

• Increases left ventricular volume and afterload 1
• Mitral valve prolapse: Murmur moves later in systole and softens 1, 2
• Hypertrophic cardiomyopathy: Murmur decreases 1, 3
• Aortic stenosis: Murmur may increase slightly 1

Valsalva Maneuver

• Decreases venous return and left ventricular volume 1
• Mitral valve prolapse: Murmur increases 1, 3
• Hypertrophic cardiomyopathy: Murmur increases (pathognomonic finding) 1, 3
• Most other murmurs: Decrease 1

Handgrip Exercise

• Increases afterload and left ventricular volume 1, 2
• Mitral regurgitation (ischemic, functional, rheumatic): Murmur increases 2
• Mitral valve prolapse: Murmur softens or moves later in systole 2
• Aortic stenosis: Murmur decreases 1

Post-Premature Beat or Long R-R Interval

• Aortic stenosis: Murmur increases in intensity 1
• Mitral regurgitation: Murmur does not increase 1

Distinguishing Specific Valve Lesions

Mitral Valve Prolapse

Listen for the midsystolic click followed by late systolic murmur—the hallmark of MVP. 1

• Classic finding: Midsystolic click(s) with or without late systolic murmur 1
• Click timing: Varies with loading conditions—moves closer to S1 with standing, later with squatting 1
• Murmur character: Medium to high-pitched, occasionally musical or honking 1
• Key differentiator: Standing makes murmur longer and louder, handgrip makes it softer—opposite of other mitral regurgitation causes 2

Aortic Stenosis

Identify the harsh crescendo-decrescendo murmur at 2nd RIS with carotid radiation and delayed carotid upstroke. 1

• Murmur location: Maximal at 2nd RIS, radiates to carotids 1
• Carotid pulse: Parvus et tardus (weak and delayed) in severe cases 1
• Associated findings: Systolic thrill at 2nd RIS, single or paradoxically split S2 1
• Post-ectopic beat: Murmur intensity increases 1

Mitral Regurgitation (Non-Prolapse)

Recognize the holosystolic murmur at apex radiating to axilla that increases with handgrip. 1, 2

• Ischemic MR: Holosystolic murmur, increases with handgrip, does not worsen with standing 2
• Functional MR: Midsystolic murmur, increases with handgrip 2
• Rheumatic MR: Holosystolic murmur, relatively fixed intensity, no dynamic positional changes 2

Aortic Regurgitation

Detect the high-pitched diastolic decrescendo murmur at left sternal border, best heard with patient leaning forward. 1

• Murmur location: 2nd-4th LIS at left sternal border 1
• Pulse pressure: Widened in chronic severe AR 1
• Carotid pulse: Brisk, jerky with systolic rebound 1

When to Order Echocardiography

Follow these Class I recommendations from ACC/AHA guidelines for immediate echocardiography:

Mandatory Echocardiography (Class I)

• All diastolic murmurs (except innocent venous hum/mammary souffle) 1
• All continuous murmurs (except innocent venous hum/mammary souffle) 1
• All holosystolic murmurs 1
• All late systolic murmurs 1
• Murmurs with ejection clicks 1
• Murmurs radiating to neck or back 1
• Grade ≥3 midsystolic murmurs 1
• Any murmur with symptoms: heart failure, syncope, thromboembolism, endocarditis, myocardial ischemia 1
• Murmurs that increase with Valsalva or standing and decrease with squatting (suggests HCM or MVP) 1, 3

Echocardiography NOT Needed (Class III)

• Grade ≤2 midsystolic murmurs in asymptomatic young patients with otherwise normal examination and no abnormal dynamic responses 1

Common Pitfalls to Avoid

Never dismiss a murmur based solely on intensity—dynamic characteristics and associated findings determine significance. 3

• Auscultate directly on skin, not through gowns—this introduces artifacts and reduces sound quality 4
• Do not skip dynamic maneuvers—a soft murmur that increases with Valsalva requires immediate workup 3
• Recognize aortic sclerosis in elderly patients: midsystolic murmur grade 1-2, no LV hypertrophy on ECG, peak velocity <2.0 m/s on echo 1
• Distinguish physiologic regurgitation on echo (trace tricuspid/pulmonic regurgitation is normal) from pathologic murmurs 1
• In hemodynamically unstable patients, perform bedside cardiac ultrasound immediately to identify valve dysfunction, tamponade, or other mechanical causes 1
• For suspected endocarditis, obtain echocardiography promptly; TEE is superior to TTE for prosthetic valves 1