How do you approach and manage a heart murmur?

Approaching and Managing Heart Murmurs

Start with systematic cardiac auscultation focusing on timing (systolic vs. diastolic), intensity (grade 1-6), location, and response to dynamic maneuvers—then use these characteristics to determine whether echocardiography is needed. 1

Initial Assessment: What to Listen For

Timing is the most critical characteristic because it determines your next steps:

• Diastolic murmurs virtually always represent pathology and require echocardiography regardless of intensity 1, 2
• Continuous murmurs (except cervical venous hums and mammary souffles in pregnancy) require echocardiography 1, 2
• Systolic murmurs require further characterization before deciding on workup 1

Systolic Murmur Classification

Determine the specific type:

• Holosystolic murmurs (throughout systole at apex or left sternal edge) → suggests mitral regurgitation, tricuspid regurgitation, or VSD → requires echocardiography 1, 2, 3
• Late systolic murmurs (starting mid-to-late systole) → suggests mitral valve prolapse → requires echocardiography 1, 2
• Midsystolic murmurs (crescendo-decrescendo pattern) → may be innocent or pathologic → grade determines next step 1

Dynamic Auscultation: Critical Maneuvers

Perform these maneuvers on all systolic murmurs to identify high-risk features:

Valsalva Maneuver

• Murmur increases during Valsalva → suggests hypertrophic cardiomyopathy or MVP → requires immediate echocardiography 1, 2
• Most other murmurs decrease with Valsalva 1

Positional Changes

• Murmur becomes louder when standing and softer when squatting → suggests hypertrophic cardiomyopathy or MVP → requires echocardiography 1, 2
• Innocent murmurs typically diminish or disappear when standing 4, 5

Handgrip Exercise

• Murmur increases with sustained handgrip → suggests mitral regurgitation or VSD → requires echocardiography 1, 2

Post-Premature Ventricular Contraction

• Murmur does NOT increase after PVC or long R-R interval in atrial fibrillation → suggests mitral regurgitation or VSD → requires echocardiography 1, 2
• Stenotic valve murmurs increase after PVC 1

Respiration

• Right-sided murmurs increase with inspiration 1, 3
• Left-sided murmurs louder during expiration 1

When to Order Echocardiography

Absolute Indications (Order Echo Immediately)

• All diastolic murmurs (any grade) 1, 2, 3
• All continuous murmurs (except venous hums and mammary souffles) 1, 2
• Holosystolic or late systolic murmurs at apex or left sternal edge 1, 2
• Grade 3 or louder midsystolic murmurs 1, 2
• Any murmur with positive dynamic maneuvers (increases with Valsalva, louder standing, increases with handgrip, no increase post-PVC) 1, 2

Symptomatic Patients (Even with Soft Murmurs)

Order echocardiography for any grade murmur when accompanied by:

• Syncope 1, 2
• Angina or myocardial ischemia/infarction 1, 2
• Heart failure symptoms 1, 2
• Thromboembolism 1, 2
• Signs of infective endocarditis (fever, petechiae, Osler's nodes, Janeway lesions) 1, 2

Additional Physical Findings Requiring Echo

Even for grade 1-2 midsystolic murmurs, order echocardiography when:

• Fixed splitting of S2 → suggests atrial septal defect 1
• Soft or absent A2, or reversed splitting of S2 → suggests severe aortic stenosis 1
• Systolic ejection sounds 1, 2
• LV dilatation on palpation or bibasilar rales → suggests severe chronic MR 1
• Slow-rising, diminished arterial pulse (pulsus parvus et tardus) → suggests severe AS 1
• ECG abnormalities (ventricular hypertrophy, atrial enlargement) 1, 2
• Chest X-ray abnormalities 1, 2

Innocent Murmurs: When NO Workup is Needed

An innocent murmur can be diagnosed clinically without echocardiography when ALL of the following are present:

• Grade 1-2 intensity 1, 2, 4
• Midsystolic (crescendo-decrescendo) pattern 2, 3, 4
• Left sternal border location 2
• Normal intensity and splitting of S2 2, 3
• No other abnormal cardiac sounds 2, 3
• Asymptomatic patient 1, 2, 4
• Normal physical examination (no ventricular hypertrophy or dilatation) 1, 2
• Does NOT increase with Valsalva or standing 2, 3
• Normal ECG and chest X-ray (if obtained) 1, 2
• Diminishes or disappears when standing 4, 5

This applies particularly to children and young adults 1, 4, 6

Critical Pitfalls to Avoid

Never Dismiss These Combinations

• Ejection systolic murmur + exertional syncope → requires immediate echocardiography until structural heart disease excluded 3
• Grade 1-2 murmur in elderly with hypertension → may represent sclerotic aortic valve or flow into tortuous vessels → lower threshold for echo 2

Interpretation Caveats

• Trivial valvular regurgitation may be detected by Doppler in many normal patients with no audible murmur → interpret echo findings in clinical context 1, 2
• Severe aortic stenosis with reduced ejection fraction → murmur may be softer than expected → don't be falsely reassured by low-grade murmur 3
• Combined valvular lesions (especially aortic and mitral disease) are commonly missed on clinical examination → maintain high suspicion 3
• Elderly patients with severe AS → typical pulsus parvus et tardus may be absent due to vascular aging 1

Role of Additional Testing

Cardiac Catheterization

• Not necessary for most patients with diagnostic echocardiograms 1
• Reserved for discrepancies between echo and clinical findings 1

Exercise Testing

• Valuable for patients with valvular disease whose symptoms are difficult to assess 1
• Safe even in asymptomatic patients with severe aortic stenosis 1
• Underutilized but should be important component of evaluation 1