Heart murmur evaluation: innocent or pathological in Australian general practice

The task in general practice

A heart murmur is an auscultatory sound produced by turbulent blood flow through the heart or great vessels. Detecting a murmur on examination is common — encountered in well-child checks, pre-operative assessments, cardiovascular consultations, and routine adult health reviews. The clinical task is to determine whether the murmur is innocent (a benign sound from a structurally normal heart) or pathological (arising from structural or haemodynamic disease), and to arrange appropriate investigation or referral.

The Heart Foundation Australia and the National Heart Foundation of Australia / Cardiac Society of Australia and New Zealand (NHFA/CSANZ) support a targeted-referral approach: not every murmur requires an echocardiogram, but any murmur with pathological features does. The cardinal rule is straightforward — any diastolic murmur in an adult requires echocardiography; diastolic murmurs are essentially never innocent beyond childhood.

Understanding what auscultation tells you from timing, grade, location, radiation, character, and dynamic response allows confident separation of innocent from pathological murmurs in the majority of cases encountered in general practice.

A. Core clinical — the AU general-practice framework

History to take

A focused cardiac history before auscultation improves clinical yield considerably.

Symptoms that change management urgency:

• Exertional syncope or presyncope — classic for aortic stenosis or hypertrophic obstructive cardiomyopathy (HOCM); never attributed to a vasovagal cause without first excluding structural disease
• Angina on exertion — particularly significant in the context of aortic stenosis; signals haemodynamically significant obstruction
• Dyspnoea — exertional dyspnoea grades the functional burden; orthopnoea and paroxysmal nocturnal dyspnoea indicate pulmonary congestion
• Palpitations — atrial fibrillation is a common complication of mitral stenosis and advanced mitral regurgitation
• Embolic events — TIA, stroke, or peripheral arterial occlusion in a patient with mitral stenosis and atrial fibrillation warrants urgent anticoagulation review

Past history:

• Rheumatic fever, scarlet fever, or recurrent streptococcal sore throats in childhood
• Known congenital heart disease or prior cardiac surgery
• Prior infective endocarditis; prosthetic valve
• Recent dental procedure or invasive procedure in the past 3 months

Risk substrate for endocarditis:

• Intravenous drug use (current or recent)
• Indwelling central venous catheter or haemodialysis access
• Immunosuppression

Family history:

• Sudden cardiac death before age 50 (HOCM, inherited channelopathy)
• Bicuspid aortic valve, Marfan syndrome, or connective tissue disorder

Aboriginal and Torres Strait Islander identity: Rheumatic heart disease (RHD) prevalence is markedly elevated in remote and regional Aboriginal and Torres Strait Islander communities (RHD Australia). Confirm RHD register status and adherence to secondary prophylaxis with every murmur assessment in Indigenous patients.

Examination sequence

General inspection → pulse character and rate → blood pressure (both arms if aortic pathology suspected) → jugular venous pressure → praecordial inspection and palpation (apex position, heave, thrill) → four-point auscultation → axilla and carotids → peripheral oedema → hepatomegaly → peripheral stigmata of endocarditis (splinter haemorrhages, Osler nodes, Janeway lesions, Roth spots on fundoscopy).

Four-point auscultation:

1. Aortic area — 2nd intercostal space, right sternal border
2. Pulmonary area — 2nd intercostal space, left sternal border
3. Tricuspid area — 4th–5th intercostal space, left sternal border
4. Mitral area (apex) — 5th intercostal space, midclavicular line; use the bell for low-pitched sounds; roll patient to left lateral for mitral stenosis

Extra sites: Erb’s point (3rd left sternal border) for aortic regurgitation; carotids for aortic stenosis radiation; axilla for mitral regurgitation radiation; back for coarctation.

Dynamic manoeuvres:

• Valsalva (strain phase) — reduces venous return; HOCM murmur louder; mitral valve prolapse click moves earlier; most other murmurs softer
• Stand to squat / passive leg raise — increases venous return and afterload; aortic stenosis louder; HOCM softer
• Sustained handgrip — increases systemic afterload; mitral regurgitation, aortic regurgitation, and ventricular septal defect louder; HOCM softer
• Inspiration — increases right-heart return; tricuspid regurgitation louder (Carvallo’s sign)
• Expiration, sitting forward, breath held — best for aortic regurgitation
• Left lateral decubitus, bell at apex — best for mitral stenosis rumble

Pulse character and extra heart sounds:

• Slow-rising, low-volume pulse (pulsus parvus et tardus) → aortic stenosis
• Collapsing, bounding, wide pulse pressure → aortic regurgitation
• Soft or absent A2 → severe aortic stenosis
• Fixed split S2 → atrial septal defect
• Opening snap after S2 → mitral stenosis
• S3 (volume overload, normal under 40s) or S4 (stiff ventricle) → assess in context
• Mid-systolic click → mitral valve prolapse

B. Classifying murmurs by timing

Systolic murmurs

Ejection systolic (mid-systolic, crescendo-decrescendo):

• Aortic stenosis — right upper sternal border radiating to carotids; harsh, grade 2–5/6; pulsus parvus et tardus; soft or absent A2 in severe disease (ACC/AHA 2020)
• Aortic sclerosis — same location; calcified leaflets but no haemodynamic obstruction; S2 intact; no radiation; common over 65; cardiovascular risk marker
• HOCM — lower left sternal border; louder with Valsalva and standing; softer with squat; family history of sudden cardiac death
• Pulmonary stenosis — left upper sternal border, radiates to left shoulder; congenital
• Innocent flow murmur — lower left sternal border; grade 1–2/6; vibratory or blowing; no radiation; normal S2; varies with position

Regurgitant systolic (holosystolic, pansystolic plateau):

• Mitral regurgitation — apex radiating to axilla; primary (degenerative, prolapse, chord rupture) or secondary (functional, from left ventricular remodelling or ischaemia)
• Tricuspid regurgitation — lower left sternal border; louder on inspiration (Carvallo’s sign); usually secondary to pulmonary hypertension or right ventricular dilation
• Ventricular septal defect — lower left sternal border; harsh; thrill often present; small defects can be very loud (Roger’s disease)

Late systolic with click:

• Mitral valve prolapse — mid-systolic click followed by late systolic murmur; click moves earlier with Valsalva and standing

Diastolic murmurs — always pathological

Any diastolic murmur requires echocardiogram; refer.

Early decrescendo (high-pitched, blowing):

• Aortic regurgitation — left sternal border, Erb’s point; heard best sitting forward in expiration; collapsing pulse; widened pulse pressure
• Pulmonary regurgitation — left sternal border; Graham Steell murmur from pulmonary hypertension

Mid-to-late diastolic rumble (low-pitched, bell at apex in left lateral decubitus):

• Mitral stenosis — apex; opening snap followed by decrescendo-crescendo low rumble; loud S1; predominantly rheumatic aetiology in Australia, especially in Aboriginal and Torres Strait Islander communities and recent migrants from endemic regions (RHD Australia)
• Tricuspid stenosis — lower left sternal border; rare; rheumatic

Continuous murmurs — always pathological

Span systole and diastole; always require echocardiogram:

• Patent ductus arteriosus — left upper sternal border; “machinery” murmur; congenital, may present in adults
• Arteriovenous fistula — iatrogenic (dialysis access) or post-traumatic
• Venous hum — innocent in children; infraclavicular; abolished by supine position or neck pressure; not pathological

Innocent murmurs — the six S’s

The Heart Foundation Australia and the ACC/AHA endorse clinical assessment over routine echocardiography for murmurs meeting all six criteria:

1. Soft (≤2/6)
2. Systolic only (never diastolic or continuous)
3. Short (early-to-mid ejection, not holosystolic)
4. Single sound (no extra heart sounds or clicks)
5. Small — no radiation
6. Sensitive — varies with position, respiration, or physiological state

Still’s murmur (vibratory, musical, lower left sternal border, grade 1–2/6) is the most common innocent murmur in children aged 3–8.

C. Investigations and referral

First-line GP investigations

ECG — left ventricular hypertrophy (aortic stenosis, hypertension, HOCM), right ventricular hypertrophy (pulmonary hypertension, pulmonary stenosis), left atrial enlargement (mitral stenosis, mitral regurgitation), atrial fibrillation, LBBB; MBS item 11700 (GP-performed 12-lead ECG).

Chest X-ray — cardiomegaly, pulmonary venous congestion, Kerley B lines, valve calcification (aortic), post-stenotic dilation, rib notching (coarctation).

Transthoracic echocardiogram (TTE) — the definitive non-invasive investigation for any pathological murmur. Provides valve anatomy, gradient, regurgitant severity, chamber dimensions and function, pulmonary artery pressure, and aortic root dimensions. First-line per ACC/AHA 2020 and ESC/EACTS 2021. MBS items 55113/55117 (specialist-billed).

Blood cultures (three sets, before antibiotics) — for any febrile patient with a new murmur, intravenous drug use, indwelling catheter, prosthetic valve, or recent invasive procedure. Infective endocarditis is the diagnosis to exclude.

BNP or NT-proBNP — supplementary; elevated or rising levels support heart failure from valve disease (NHFA/CSANZ).

Bloods for high-output flow murmurs — FBC (anaemia), TSH (thyrotoxicosis), iron studies.

Referral urgency

Finding	Action
Any diastolic murmur	Echocardiogram + cardiology referral
Any continuous murmur	Echocardiogram + cardiology referral
Systolic murmur ≥3/6	Echocardiogram
Any murmur + symptoms	Echocardiogram + cardiology (urgent if syncope, angina, or heart failure)
Any murmur + abnormal ECG or CXR	Echocardiogram
New murmur + fever or intravenous drug use	Same-day emergency department
Exertional syncope in a young person	Suspend exertion; urgent structural workup
Innocent murmur, high clinical certainty	Reassure; safety-net

D. Australian operations

MBS items relevant in general practice

• GP consultations — items 23 (Level B), 36 (Level C), 44 (Level D); a new murmur requiring complete cardiovascular examination typically warrants a Level C or D consultation
• Heart Health Check — item 699 (age ≥30) or 715 (Aboriginal and Torres Strait Islander patients, all ages); cardiovascular auscultation is a core component
• 75+ Health Assessment — item 707; includes auscultation
• 12-lead ECG GP-performed — items 11700/11701
• TTE — items 55113/55117 (specialist-billed); GP refers via cardiology
• Transoesophageal echocardiogram — items 55141–55143 (specialist-billed)
• Specialist referral — items 105/106 (cardiology outpatient)
• Aboriginal and Torres Strait Islander Health Assessment — item 715 (any age)

Referral pathways

General cardiology outpatient — initial echocardiogram and specialist opinion; major public hospitals accept direct GP referrals. Send referral with auscultatory findings documented, ECG, CXR, symptoms, and functional status.

Heart Team — TAVI, transcatheter edge-to-edge repair (TEER/MitraClip), surgical valve repair or replacement decisions; major tertiary centres. PARTNER 3 (Mack NEJM 2019) demonstrated TAVI non-inferior to surgery in low-risk aortic stenosis, broadening eligibility.

RHD Australia — coordinates state-based registers and secondary prophylaxis for Aboriginal and Torres Strait Islander patients (rhdaustralia.org.au); confirm register status and Bicillin LA programme adherence at every encounter.

Telehealth cardiology — available for rural and regional access; video preferred when initial clinical examination has already been documented.

Endocarditis prophylaxis

Per eTG Antibiotic guidelines and NICE CG64: indications are now narrow — prosthetic valve, prior infective endocarditis, selected congenital heart disease, transplant valvulopathy, and RHD in Indigenous patients; high-risk dental procedures only. Routine prophylaxis for all murmurs is not recommended. Good daily dental hygiene and regular dental review reduce infective endocarditis risk more than peri-procedural antibiotics.

Driving and occupational fitness

Austroads — Assessing Fitness to Drive 2022 covers: exertional syncope, severe symptomatic aortic stenosis, post-cardiac surgery, and post-TAVI restrictions. Commercial driver standards are stricter than private licensing. Document fitness discussions at every cardiac encounter.

E. Special populations

Children and adolescents. Innocent murmurs are very common in children — audible in up to 50–80% at some point in childhood. Routine echocardiography is not required if all six features of an innocent murmur are present and there is no family history of structural heart disease or sudden cardiac death. An echocardiogram is appropriate when there is any clinical uncertainty, or if the child has symptoms, an abnormal ECG, or family history concern.

Pregnancy. High-output physiology produces audible flow murmurs in the majority of pregnant women. These are innocent. Any diastolic murmur in pregnancy is pathological and requires echocardiography. New severe mitral regurgitation with fever raises concern for infective endocarditis. Significant aortic stenosis in pregnancy carries substantial maternal and foetal risk; specialist obstetric cardiology input is essential.

Aboriginal and Torres Strait Islander patients. RHD remains the dominant structural valve cause in Indigenous Australians from remote areas. Mitral stenosis, mitral regurgitation, and mixed valve disease secondary to RHD are seen at ages far younger than in the general population. All patients with an Indigenous background and a murmur should have RHD register status confirmed. Secondary prophylaxis with monthly Bicillin LA is the cornerstone of disease management alongside valve surveillance.

Athletes. Exertional syncope with a murmur in a young athlete suggests HOCM until proven otherwise. Exertion should be suspended until echocardiography, ECG, and family history review are complete. Innocent murmurs are particularly prevalent in trained athletes because of high stroke volume and cardiac output.

Older adults. Aortic sclerosis (leaflet calcification without significant obstruction) is present in up to 20–30% of adults over 65 and produces a systolic ejection murmur. It is a marker of cardiovascular risk but does not itself require intervention. Progression to haemodynamically significant aortic stenosis occurs in approximately 10–15% of those with sclerosis over five years; annual auscultation with echocardiogram when features change is appropriate.

When to escalate

Refer to the emergency department or request urgent hospital assessment in any of the following situations:

• New murmur with fever — infective endocarditis until blood cultures prove otherwise
• Acute pulmonary oedema from valve disease
• Exertional syncope with a murmur in any age group — structural workup before any further physical exertion
• Acute severe aortic regurgitation (endocarditis, aortic dissection) with shock
• Acute severe mitral regurgitation (papillary muscle rupture post-MI, chord rupture from endocarditis)
• Any patient deteriorating despite established diagnosis and medical management

What this article is and is not

This is general health information based on Australian general practice guidelines — Heart Foundation Australia, NHFA/CSANZ, Therapeutic Guidelines, AMH, RACGP, ACC/AHA 2020, and ESC/EACTS 2021. It is not personal medical advice and does not create a doctor–patient relationship. Decisions about echocardiography, referral, and management depend on individual clinical assessment by a qualified clinician who has examined the patient.

For consumer-friendly information: Heart Foundation Australia, HealthDirect — Heart valve disease, Better Health Channel — Heart valve problems.

For Aboriginal and Torres Strait Islander patients: RHD Australia.

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Sources cited

1. Heart Foundation Australia (NHFA)
2. Cardiac Society of Australia and New Zealand (CSANZ)
3. Therapeutic Guidelines (eTG) — Cardiovascular + Antibiotic
4. Australian Medicines Handbook (AMH)
5. RACGP
6. ACC/AHA 2020 Guideline for Valvular Heart Disease
7. ESC/EACTS 2021 Guidelines for Valvular Heart Disease
8. RHD Australia — ARF and RHD Guidelines
9. NICE CG64 — Prophylaxis Against Infective Endocarditis
10. Mack MJ et al — PARTNER 3 trial (NEJM 2019)
11. Stone GW et al — COAPT trial (NEJM 2018)
12. Austroads — Assessing Fitness to Drive 2022
13. HealthDirect
14. Better Health Channel