Figure 4
From: Phono-spectrographic analysis of heart murmur in children
![Figure 4](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2F1471-2431-7-23/MediaObjects/12887_2006_Article_159_Fig4_HTML.jpg)
Aortic stenosis in a 7-month-old. A third-degree coarse, stenosis-type murmur that does not last until the end of systole is heard in the aortic area. Echocardiography revealed aortic valve stenosis with a 45-mmHg flow gradient. The phonogram shows a diamond-shaped murmur, and the spectrogram contains early systolic sound waves of approx. 500 Hz that coincide with the peak aortic flow. Age 0.6 years. Auscultation area: left third intercostal space (LIC3). Duration 98 %, peak frequency 530 Hz and volume 92 %.