Does Echocardiography Have a Role in the Cardiologist's Diagnosis of Innocent Murmurs in Childhood?

BACKGROUND

Innocent murmurs are common in childhood. Echocardiography may diagnose almost all congenital cardiac abnormalities. Earlier studies have suggested that it may be unnecessary when a clinical diagnosis of an innocent murmur is made by an experienced cardiologist. Yet, echocardiography is commonly performed despite such a diagnosis. Is that justifiable?

METHODS

Patients referred to a paediatric cardiologist for evaluation of a murmur were assessed. If an innocent murmur was clinically diagnosed, an echocardiogram and an electrocardiogram were ordered when requested. The cardiologist completed a questionnaire documenting the reasons for the investigations and his degree of confidence in the clinical diagnosis. The parents and patients were informed of the diagnosis and the results of the investigations.

RESULTS

In almost all 62 cases whose murmurs were clinically considered to be innocent, the referring doctor expected an echocardiogram to be performed. Following echocardiography, one patient was found to have a small muscular ventricular septal defect. On review, the murmur was consistent with that diagnosis. Three (3) others had abnormal echocardiograms namely congenitally corrected transposition of great arteries, partial anomalous right upper lobe pulmonary vein, and left ventricular non-compaction. All on review were still considered clinically to have innocent murmurs.

CONCLUSIONS

Despite the competency of the cardiologist, echocardiography diagnosed important but relatively uncommon cardiac abnormalities with prognostic implications that would have been missed if only the clinical examination was performed. Over and above the referring doctor's expectations for an echocardiogram to be performed is the need for the cardiologist to provide a complete and definitive diagnosis.