Value of routine chest radiograph (CXR) and electrocardiogram (EKG) in the evaluation of isolated neonatal murmurs

A heart murmur is a common finding during the neonatal period; however, the prevalence of congenital heart disease is approximately 1%. Excluding Patent Ductus Arteriosus, the majority of congenital heart disease is attributable to Ventricular Septal Defects (VSD); most of these VSD's present as isolated murmurs without other clinical signs and tend to close spontaneously. It is common practice to obtain a CXR and EKG in the evaluation of neonatal murmurs even in the absence of other clinical signs. Most evaluations of neonatal murmurs by Cardiology include an echocardiogram (ECHO). With such frequent use of echocardiography during the neonatal period, we question the routine use of obtaining a CXR and EKG to confirm the clinical impression of an asymptomatic VSD. We reviewed the records of neonates born at > 35 weeks gestation referred to Cardiology during the first five days of life for evaluation of a heart murmur. We identified those with the ECHO diagnosis of asymptomatic VSD (N=37) and Normal (N=40); we examined the CXR and EKG for abnormal findings in relation to the ECHO diagnosis. The odds ratio (OR) for an abnormal CXR in neonates with an asymptomatic VSD compared to Normal infants with a murmur was .62 (95%CI=. 18-2.06); the sensitivity (S) of a CXR was .15, and the positive predictive value (PPV) was .36. The OR for an abnormal EKG was .64 (95%CI=.22-1.87) with the S=.19 and the PPV= .37. We conclude that an asymptomatic infant with an isolated murmur does not warrant a CXR and EKG but that a referral to Cardiology or close follow up is necessary. If the murmur is associated with respiratory symptoms and/or cyanosis, a CXR and EKG may be of screening value.