Children with heart murmurs: can ventricular septal defect be diagnosed reliably without an echocardiogram?

OBJECTIVES

This study was undertaken to determine the accuracy of expert examination for ventricular septal defect (VSD) among children with a heart murmur.

BACKGROUND

Because the frequency and nature of errors that might be made by reliance solely on expert examination for diagnosis of VSD are speculative, the role of echocardiography in such diagnosis is controversial.

METHODS

Two hundred eighty-seven consecutive previously unevaluated pediatric subjects were enrolled in the study. For each child, the pediatric cardiologists prospectively recorded a working diagnosis and their level of confidence in the diagnosis, categorizing any VSD diagnosed as small or moderate to large. After echocardiography, VSDs were subcategorized by location and requirement for treatment as minor, intermediate or major. Receiver-operating characteristic (ROC) curves described the accuracy of the clinical examination.

RESULTS

Seventy-three subjects had a VSD (minor in 52, intermediate in 10 and major in 11). ROC areas (1.0 = perfect discrimination, 0.5 = indiscriminate) were minor VSD 0.92 +/- 0.02 and major/intermediate VSD 0.69 +/- 0.07 (p = 0.0016). Four of 52 minor VSDs were not identified at any level of suspicion; the clinical diagnoses were moderate to large VSD in two patients and atrial septal defect and unlimited differential diagnosis in one patient each. Fourteen of 235 patients without a minor VSD were believed with confidence to have a small VSD, but the final diagnosis was intermediate VSD in 4, innocent murmur in 3, major VSD in 2, pulmonary stenosis in 2 and subaortic membrane, atrial septal defect and mitral regurgitation in 1 patient each.

CONCLUSIONS

Almost all minor VSDs are recognized without echocardiography; however, errors can occur even when an expert examiner is confident. Clinical recognition of an intermediate or major VSD is less accurate than clinical recognition of a minor VSD. Failure to distinguish VSDs of major or intermediate importance from minor VSDs is a weakness of the expert clinical examination.