Innocent versus pathologic murmurs: A challenge of neonatal examination

Objective: Auscultation is one of the most important procedures in routine examination of neonates for congenital heart disease (CHD). Differentiating between innocent and pathologic murmurs during auscultation is very hard and usually unfeasible. The aim of this study was to assess the ability of clinical examination in comparison to echocardiographic examination to differentiate innocent from pathological murmurs and also to define the prevalence of heart murmurs in neonates. Materials and Methods: In the current cross-sectional study, 7113 neonates were examined in a period of 1 year by two neonatologists. If heart murmurs or unnatural sounds were auscultated during the examination, the observations were categorized as “probably pathologic” or “probably innocent” and the neonates were then referred to a pediatric cardiologist for echocardiography. Results: Prevalence of heart murmurs was found to be 19.26 for every thousand live births. According to the clinical examinations, 55% of murmurs were categorized as innocent and 45% as pathologic. Echocardiographic results revealed that in fact 50.8% of cases were either normal or had physiological defects and 49.2% were pathologic. Sensitivity, specificity, positive predictive value, and negative predictive value of clinical examination in differentiating between innocent and pathologic murmurs were found to be 79.7%, 88.5%, 87%, and 81.8%, respectively, and the false-positive and false-negative rates were found to be 11.5% and 20.3%, respectively. Conclusion: Although these numbers show that clinical examination is adequate for differentiating between innocent murmurs and CHD, however the false-positive and false-negative rates in clinical examination, stress that echocardiography must be performed for a better CHD diagnosis.