Significance of a cardiac murmur as the sole clinical sign in the newborn

A cardiac murmur is a very common finding in the first few days of life. It is traditionally believed that lesions creating left-to-right shunts do no t present so early. This study was aimed to define and to classify the caus es of a murmur in a ne newborn with an other wise normal examination. All e chocardiograms performed on newborns aged 1-5 days who were referred for ev aluation of a murmur in a 3-year period were reviewed. Newborns with additi onal clinical signs or antenatal diagnosis of a cardiac disease were exclud ed. Of 20,323 live births, there were 170 newborns referred for echocardiog ram solely because of a murmur Of these, 147 (86%) were found to have struc tural heart defects, The most common lesions found were those creating left -to-right shunts (66%). Ventricular septal defect was the most common singl e lesion (54/147, 37%), followed by patent ductus arteriosus (34 newborns, 23%). The combination of both was found in 10 newborns (7%). Six newborns ( 4%) had pulmonary valve stenosis and three (2%) aortic valve stenosis. Seve n newborns (5%) had unforeseen complex heart: disease; For five of them, de layed diagnosis would have resulted in potentially life-threatening conditi ons, There was no correlation between the category of lesion and the age of presentation. The audible threshold of a murmur correlated with a maximum instantaneous gradient of 25 mm Hg (range 11-46 mm Hg), Thirteen percent of newborns with isolated heart murmur had no identifiable structural heart d isease. These data suggest that most asymptomatic newborns presenting with a murmur in the first days of life have structural heart disease. Some of t he more serious defects would not have been diagnosed without early echocar diography. A left-to-right shunt, particularly a ventricular septal defect, may cause a murmur even the first day of life and is probably more common that has been acknowledged.