How do you check for a heart murmur?

How to Check for a Heart Murmur

Systematic Auscultation Technique

Cardiac auscultation remains the primary screening method for detecting heart murmurs, requiring systematic assessment of timing, intensity, location, configuration, pitch, and radiation patterns. 1

Essential Auscultation Components

• Listen at all standard cardiac areas: aortic area, pulmonic area, left sternal border, and apex, using both the diaphragm and bell of the stethoscope 1

• Grade murmur intensity on a 1-6 scale for systolic murmurs (Grade 1 = very faint, Grade 6 = extremely loud with palpable thrill) 2

• Determine timing in the cardiac cycle: systolic (between S1 and S2), diastolic (after S2), or continuous 1

• Assess configuration: crescendo, decrescendo, crescendo-decrescendo (diamond-shaped), or plateau 1

• Identify location and radiation: note where the murmur is loudest and where it radiates (neck, back, axilla) 1

Dynamic Cardiac Auscultation

Dynamic maneuvers are critical for determining the clinical significance of murmurs and should be performed routinely. 1

Key Maneuvers to Perform

• Valsalva maneuver: Murmurs that increase with Valsalva suggest hypertrophic cardiomyopathy or mitral valve prolapse and require immediate workup 2

• Positional changes: Have the patient stand from squatting position—murmurs that become louder when standing and decrease when squatting indicate hypertrophic cardiomyopathy or mitral valve prolapse 2

• Sustained handgrip exercise: Murmurs that increase during handgrip suggest mitral regurgitation or ventricular septal defect 2

• Post-premature ventricular contraction: Murmurs that do not increase after a PVC suggest mitral regurgitation or ventricular septal defect 2

• Respiration: Right-sided murmurs typically increase with inspiration 1

Classification of Murmurs

Systolic Murmurs

• Holosystolic (pansystolic): Occur throughout systole, typically indicate mitral regurgitation, tricuspid regurgitation, or ventricular septal defect 1

• Midsystolic (ejection): Diamond-shaped, peak in mid-systole, may be innocent or indicate aortic stenosis, pulmonic stenosis, or high-flow states 1

• Late systolic: Begin in mid-to-late systole, often associated with mitral valve prolapse 1

Diastolic Murmurs

• All diastolic murmurs are pathologic and require echocardiography regardless of intensity 2, 3

• Early diastolic: High-pitched, decrescendo, typically indicate aortic or pulmonic regurgitation 1

• Mid-diastolic: Lower-pitched, suggest mitral stenosis or increased flow across mitral valve 1

Continuous Murmurs

• All continuous murmurs require echocardiography (except innocent venous hums and mammary souffles) 2, 3

Identifying Innocent Murmurs

In asymptomatic adults, certain characteristics reliably identify innocent murmurs that require no further workup. 2

Characteristics of Innocent Murmurs

• Grade 1-2 intensity at the left sternal border 2

• Systolic ejection pattern (diamond-shaped configuration) 2

• Normal intensity and splitting of S2 2

• No other abnormal cardiac sounds (no clicks, gallops, or additional murmurs) 2

• No evidence of ventricular hypertrophy or dilatation on examination 2

• Does not increase with Valsalva or standing 2

• Common in high-output states such as anemia, pregnancy, fever, or hyperthyroidism 1

When to Order Echocardiography

Immediate Indications (Always Require Echo)

• All diastolic murmurs regardless of intensity 2, 3

• All continuous murmurs (except venous hums and mammary souffles) 2, 3

• Holosystolic or late systolic murmurs at apex or left sternal edge 2

• Grade 3 or louder midsystolic murmurs 2

• Any murmur with symptoms: syncope, angina, heart failure, thromboembolism, or signs of infective endocarditis 2

Indications for Grade 1-2 Midsystolic Murmurs

Even soft murmurs require echocardiography when accompanied by:

• Symptoms of infective endocarditis (fever, new murmur, embolic phenomena) 2

• Thromboembolism 2

• Heart failure symptoms (dyspnea, orthopnea, edema) 2

• Myocardial ischemia or infarction 2

• Syncope 2, 4

• Abnormal physical findings: widely split S2, systolic ejection clicks, abnormal S1 or S2 2

• ECG or chest X-ray abnormalities: ventricular hypertrophy, atrial enlargement, chamber dilatation 2

Dynamic Auscultation Findings Requiring Echo

• Increases with Valsalva, louder when standing, decreases with squatting 2

• Increases during transient arterial occlusion or sustained handgrip 2

• Does not increase after PVC or long R-R interval in atrial fibrillation 2

Critical Pitfalls to Avoid

• Never dismiss an ejection systolic murmur in a patient with exertional syncope as "innocent"—this combination requires immediate echocardiography until structural heart disease is excluded 4

• Do not rely on ECG or chest X-ray to exclude significant valvular disease—aortic stenosis, aortic regurgitation, mitral regurgitation, and hypertrophic cardiomyopathy are frequently missed by clinical examination alone 5, 6

• Recognize that trivial valvular regurgitation may be detected by echocardiography in many normal patients with no audible murmur—interpret echo findings in clinical context 1

• Be aware that combined valvular lesions (especially aortic and mitral disease) are commonly missed on clinical examination—sensitivity is only 55% for detecting combined lesions 6

• In older patients with hypertension, grade 1-2 midsystolic murmurs may reflect sclerotic aortic valve leaflets or flow into tortuous vessels, but still require evaluation if other risk factors are present 2

• Severe aortic stenosis can be misjudged when left ventricular ejection fraction is severely reduced, as the murmur may be softer than expected 6

Use of the "Inching" Technique

• Move the stethoscope systematically from aortic area to apex while keeping S2 as a reference point to accurately time sounds and murmurs 7

• Sounds occurring before S2 are systolic; sounds occurring after S2 are diastolic 7

• Apply varying pressure with the stethoscope: S4 gallops disappear with firm pressure, while ejection sounds and split S1 persist 7