Effects of electrocardiography and chest radiography on the accuracy of preliminary diagnosis of common congenital cardiac defects.

Abstract

The objective of this study was to compare the accuracy of the expert clinical examination for certain common cardiac defects with and without electrocardiogram (EKG) and chest radiogram (x-ray). The design of the study was a prospective, blinded comparison of diagnostic accuracy of the expert examination with and without EKG and x-ray, using echocardiography as the diagnostic standard. The setting of the study was the pediatric cardiology outpatient department. There were 749 outpatients with heart murmur under 21 years of age without prior echocardiography or pediatric cardiology consultation. The intervention was echocardiography as clinically indicated for evaluation of heart murmur of uncertain cause. Measurements were carried out using the incorporation of EKG and x-ray into multiple linear regression models to assess independent associations, if any, with the accuracy of clinical examination. Results were reported as the presence or absence of independent significant impact of availability of EKG and x-ray on examiner's diagnostic accuracy for innocent murmur, ventricular septal defect (VSD), pulmonary stenosis (PS), aortic valve disease, atrial septal defect (ASD), and patent ductus arteriosus. EKG enhanced detection of ASD and may have helped detect PS. X-ray enhanced detection of intermediate to large VSD. X-ray and EKG were otherwise without demonstrable independent advantage for defect-specific diagnosis. Routine use of one or both of these tests in the initial evaluation of heart murmur in the pediatric cardiology clinic should remain an option.