Heart murmurs are commonly discovered in young children during clinical encounters in general practice. Heart murmurs might signal a structural cardiac disease that need to be treated, such as atrial septal defect. Thus, children with heart murmurs are routinely referred to comprehensive cardiac examination at a paediatric hospital department featuring echocardiography ('gold standard'). However, the great majority of such murmurs are innocent or physiological; ie., they do not represent a cardiac disorder. The prevalence of such innocent murmurs during routine random auscultation is estimated at 30 %.