Causes of heart murmur can be grouped into functional, also known as innocent murmur, physiologic and pathological murmurs. Still murmur is one of the causes of functional murmur. Causes of physiologic murmur include arteriovenous fistula and pregnancy. Pathological murmur can result from a broad variety of conditions such as valvular stenosis, valvular insufficiency, mitral valve prolapse, right-to-left shunt and left-to-right shunt.

• Systolic murmur^[1]
  • Ejection murmurs
    • Functional
      • Still’s murmur and its adult variant
      • Flow murmur emanating from the root of the pulmonary artery
      • Murmur associated with high cardiac output states
      • Flow murmurs associated with aortic or pulmonary valvular insufficiency
    • Organic
      • Valvular aortic stenosis
      • Aortic sclerosis
      • Discrete subvalvular aortic stenosis (web or tunnel)
      • Supravalvular aortic stenosis
      • Hypertrophic obstructive cardiomyopathy
      • Pulmonary valvular stenosis
      • Pulmonary infundibular stenosis
      • Atrial septal defect
      • Tetralogy of Fallot
  • Regurgitant murmurs
    • Functional: none
    • Organic:
      • Mitral regurgitation:
        • Rheumatic
        • Papillary muscle dysfunction
        • Mitral valve prolapse
        • Acute
      • Tricuspid regurgitation:
        • Chronic
        • Acute
      • Ventricular septal defect
        • Roger’s type (small and large)
          • Without pulmonary hypertension
          • With pulmonary hypertension
        • Slitlike
    • Extracardiac sounds simulating systolic heart murmurs
      • Subclavian (supraclavicular/brachiocephalic) Murmur
      • Internal mammary soufflé
      • Carotid artery bruits
      • Coarctation of the aorta
      • Murmurs emanating from a dilated aortic or pulmonary artery root
      • Patent ductus arteriosus with pulmonary hypertension
        
• Diastolic murmur^[2]
  • Aortic regurgitation
  • Pulmonary valve regurgitation
  • Mitral rumble
    • Obstruction to flow
      • Mitral stenosis (rheumatic, congenital)
      • Left atrial myxoma
      • Cor triatriatum
      • Localized pericardial constriction
    • Increased flow
      • Mitral regurgitation
      • Ventricular septal defect
      • Patent ductus arteriousus
      • Complete heart block
  • Tricuspid rumble
    • Obstruction to flow
      • Tricuspid stenosis (rheumatic, Ebstein’s anomoly, carinoid)
      • Right atrial myxoma
      • Localized pericardial constriction
    • Increased flow
      • Atrial septal defect
      • Tricuspid regurgitation
• Continuous murmur ^[3]
  • THORACIC:
    • Precordial
      • Patent ductus arteriosus
      • Coronary arteriovenous fistulas
      • Sinus of Valsalva aneurysm ruptured into right cavities
      • Atrial septal defect associated with abnormalities that cause increased pressure in the left atrium
      • Left coronary artery origin from pulmonary artery anomaly
      • Continuous murmur at intern mammary artery
    • Extra Precordial
      • Coarctation of the aorta
      • Pulmonary atresia
      • Pulmonary arteriovenous fistula
      • Truncus arteriosus
      • Anomalies of origin of the pulmonary artery
  • EXTRATHORACIC:
    • Venous hum
    • Cruveilhier-Baumgarten sindrom
    • Severe arterial stenosis
    • Extrathoracic arteriovenos fistulas