Heart Murmurs

💓 Heart murmurs are extra or abnormal heart sounds caused by turbulent blood flow across the cardiac valves or within the heart. They may be innocent (physiological) or due to structural pathology such as valvular stenosis or regurgitation. Careful auscultation, combined with history and examination, helps guide diagnosis and further investigation. Systolic murmurs occur with the pulse and diastolic murmurs are asynchronous

🧬 Physiology

• Normal heart sounds (S1, S2) reflect closure of atrioventricular (mitral & tricuspid) and semilunar valves (aortic & pulmonary).
• A murmur occurs when blood flow becomes turbulent instead of laminar – e.g. through a narrowed valve (stenosis), leaky valve (regurgitation), or abnormal connection (septal defect).
• Timing is crucial:
  • 🔴 Systolic murmurs – between S1 and S2 (e.g. aortic stenosis, mitral regurgitation).
  • 🟡 Diastolic murmurs – between S2 and S1 (e.g. mitral stenosis, aortic regurgitation).
  • ⚪ Continuous murmurs – throughout systole & diastole (e.g. patent ductus arteriosus).

📋 History – Key Questions

• Symptoms: dyspnoea, chest pain, palpitations, syncope, fatigue, ankle swelling.
• Onset & duration of murmur (childhood vs adulthood).
• Risk factors: rheumatic fever, infective endocarditis, congenital heart disease.
• Functional impact: exercise tolerance, signs of heart failure.

🩺 Examination Findings: Feel pulse and listen together

• Inspection: Cyanosis, clubbing, surgical scars, peripheral oedema.
• Palpation: Apex beat (displaced in LV dilatation), thrills (palpable murmur), heaves (ventricular hypertrophy).
• Auscultation: Identify murmur timing, location, radiation, pitch, and response to manoeuvres (e.g. squatting, Valsalva).

🔎 Classification of Murmurs

🧪 Investigations

• Bedside: ECG (AF in MS, LVH in AS), BP measurement.
• Bloods: FBC (anaemia), U&E (baseline for surgery), cultures if infective endocarditis suspected.
• Imaging: Chest X-ray (cardiomegaly, pulmonary congestion).
• Echocardiography: 🔑 Gold standard for diagnosis – assesses valve morphology, severity, gradients, and cardiac function.
• Advanced: MRI/CT for complex anatomy, cardiac catheterisation if intervention planned.

⚖️ Management Principles

• 🔹 Innocent murmurs: Often benign in children/young adults – reassurance only.
• 🔹 Valve disease:
  • Stenosis: Surgical or percutaneous intervention (e.g. aortic valve replacement, balloon valvotomy).
  • Regurgitation: Valve repair or replacement, optimise preload/afterload medically until surgery indicated.
• 🔹 Medical therapy: Diuretics for heart failure, rate control for AF, anticoagulation (esp. MS with AF).
• 🔹 Infective Endocarditis Prophylaxis: Not routine in UK, but emphasise dental hygiene and risk awareness.
• 🔹 Multidisciplinary care: Involves cardiology, cardiothoracic surgery, and sometimes genetics (for congenital disease).

💡 Clinical Pearls

• 🚨 Aortic stenosis: Harsh ejection systolic murmur radiating to carotids; causes syncope, angina, dyspnoea.
• 💨 Mitral regurgitation: Pansystolic murmur radiating to axilla; common cause of left-sided heart failure.
• 🫀 Mitral stenosis: Mid-diastolic rumble with opening snap; often rheumatic heart disease, risk of AF + emboli.
• 🌊 Aortic regurgitation: Early diastolic “blowing” murmur; wide pulse pressure, collapsing “water hammer” pulse.
• 👶 Always exclude congenital causes in paediatric murmurs (VSD, ASD, PDA, TOF).