Murmurs: timing, grade, location and radiation !

Sign

A murmur is the sound of turbulent blood flow; describing it well almost always tells which valve is failing.

Updated 2026-11-01

See it in 3D: Mitral anterior leaflet · Mitral posterior leaflet · Aortic right coronary cusp · Chordae tendineae · Left ventricle papillary muscles · Interventricular septum

What it is

Murmurs come from turbulent flow through a narrow or leaking valve, a septal defect or high flow. They are always described with the same attributes: timing in the cycle, shape, location, radiation, intensity, pitch and change with maneuvers. Every diastolic murmur is pathologic.

The anatomy it tests

Stenosis: the valve does not open fully and blood speeds up through it (aortic and pulmonic in systole; mitral and tricuspid in diastole).
Regurgitation: the valve does not close and blood flows back (mitral and tricuspid in systole; aortic and pulmonic in diastole).
Septal defects: flow passes from the high-pressure to the low-pressure chamber (ventricular septal defect is holosystolic).
Murmurs radiate in the direction of the jet: aortic stenosis to the carotids, mitral regurgitation to the axilla.

How to elicit it

Identify S1 and S2 by feeling the carotid pulse and decide whether the murmur is systolic (between S1 and S2), diastolic (between S2 and S1) or continuous.
Specify timing: early, mid, late or holosystolic (from S1 to S2 without a gap).
Describe the shape: diamond (crescendo-decrescendo), plateau or decrescendo.
Find the area where it is loudest and inch the stethoscope toward the neck, axilla or back to trace radiation.
Grade intensity from 1 to 6 (Levine scale) and feel for a thrill.
Describe pitch (high, low) and quality (harsh, blowing, rumbling) and test the effect of breathing and maneuvers.

What a positive result means

Grade 1: barely audible with effort; 2: soft but clear; 3: loud, no thrill; 4: with a thrill; 5: heard with the stethoscope edge; 6: heard with the stethoscope off the chest.
Innocent murmur: midsystolic, soft (grade 1–2), no thrill, normal S2, no symptoms; common in children, pregnancy, fever and anemia.
Point to a pathologic murmur: any diastolic or holosystolic murmur, grade 3 or more, a thrill, abnormal sounds, symptoms, or louder on standing.
Fever plus a new murmur suggests infective endocarditis; in Colombia and the region rheumatic heart disease is still a common cause of mitral murmurs.

Usefulness and limits

Loudness does not measure severity: an aortic stenosis murmur can soften as the heart fails.
Echocardiography confirms the lesion and its severity; auscultation decides who needs it.

Test yourself

Think of the answer, then tap the question to see it.

What separates a grade 4/6 murmur from a grade 3/6 one?

Grade 4 comes with a palpable thrill; grade 3 is loud but has no thrill.

Which valves produce systolic murmurs when they leak?

The atrioventricular valves, mitral and tricuspid, because they should be closed during systole.

Which features suggest a murmur is innocent?

Midsystolic, soft (grade 1–2), no thrill, normal S2, an asymptomatic patient, and softer on standing.

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See it in 3D

The structures of Durgical's 3D anatomy where it is found.

← All of the clinical exam

Educational content on the clinical exam; it is learned and practised under supervision. It does not replace assessment by a health professional and is not for self-diagnosis.

Sources: Heart murmurs: MedlinePlus Medical Encyclopedia (MedlinePlus, U.S. National Library of Medicine, 2026); 24.3 Nursing Assessment - Clinical Nursing Skills | OpenStax (OpenStax (Rice University), 2024); 19.3 Cardiac Cycle - Anatomy and Physiology 2e | OpenStax (OpenStax (Rice University), 2022).

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Representative model, for educational purposes only.