Background - Cardiac mumurs are common in childhood and are often innocent in nature. With careful examination, most innocent murmurs can be reliably diagnosed by a paediatric cardiologist, thus obviating the need for further investigations.
Aim - To look at the prevalence of cardiac murmurs amongst standard one schoolchildren in an urban setting, and calculate the sensitivity, specificity, positive and negative predictive values of clinical diagnosis in differentiating innocent from pathological murmurs.
Methods - One thousand three hundred and fourteen students from 7 primary schools in the district of Gombak were examined during a routine school health examination. Those who were found to have murmurs were referred for echocardiography. A diagnosis was made at the time of clinical examination and following echocardiography. Children with median sternotomy, lateral or posterior thoracotomy scars or those with previously diagnosed cardiac lesions were excludedfrom the study.
Results - Thirty six children were referred for echocardiography out of which 2 were confirmed to have underlying cardiac disease on echocardiography. The prevalence of previously undiagnosed cardiac mumurs in this study was 3%. The sensitivity of clinical examination in diagnosing pathological murmurs was 100% while the specificity was 75%. Positive predictive value was 25% and negative predictive value was 100%. Forty three percent of the students who underwent echocardiography were found to have trivial pulmonary regurgitatibn on Doppler echocardiography.
Conclusion - The prevalence of previously undiagnosed cardiac murmurs is low in this study. This may be due to the fact that they are detected and treated at an earlier age. There is need to conduct a similar study in a rural setting to compare the results.