The vibratory innocent heart murmur in schoolchildren: Difference in auscultatory findings between school medical officers and a pediatric cardiologist

Abstract

In 810 schoolchildren heart auscultation was performed by both a school medical officer (SMO) and a pediatric cardiologist (PC). The prevalence for a grade 1, 2, or 3 vibratory innocent heart murmur (VIHM), a grade 2 or 3 VIHM, and a grade 3 VIHM heard by the PC was 41%, 13%, and 1%, respectively. The SMO noted such murmurs in 26%, 9%, and 1%, respectively. In 30% of the cases in which the PC had noted a grade 2 or 3 VIHM, the SMO agreed; in 30% of such cases the SMO did not hear any heart murmur. If the PC heard a grade 2 or 3 VIHM phonocardiography was performed in a case-control study in which the controls did not have a heart murmur (94 pairs). In four children with a grade 2 or 3 VIHM no heart murmur could be registered and in three other children the murmur did not have the typical diamond shape. In contrast, in three children without a heart murmur at school a VIHM was seen on the phonocardiogram. In 26 children with a phonocardiographically proven grade 2 or 3 VIHM the SMO did not hear any heart murmur. One child with a grade 3 VIHM (both by the PC and SMO) had a minor subvalvular aortic stenosis. There is quite a difference in auscultatory detection of a venous hum: 9% (PC) and 2% (SMO). The prevalence of the pulmonary ejection murmur is identical at 4%. The carotid bruit is heard in 4% (PC) and 2% (SMO). Pathologic murmurs were heard in 12 children by the PC, agreed by the SMO in two cases. Eight of the 12 pathologic murmurs were confirmed by further cardiologic examination and one was decided to be an innocent pulmonary ejection murmur. The auscultatory findings of 4 SMOs, who examined >100 children each, differ remarkably when compared separately to the results of the PC. Variation in intensity of the heart murmurs and difference in auscultatory skills explain the great difference in ausculatory findings between the PC and the SMO. Specialized training of SMO to recognize (pathological) heart murmurs is advocated.