[Additional phonocardiographic symptom and the functional state of the heart during mitral valve prolapse in children].

A review of the clinical pattern and heart function in 50 children (aged 6 to 15 years) with mitral valve prolapse (MVP) demonstrated that MVP was mild or of medium severity and had a favourable course in most of the cases. Systolic extratone due to MVP can be manifested to the greatest degree within the low-frequency range of phonocardiograms. Morphometric and functional electrocardiographic parameters were within the normal range in most of the children. The transitory nature of MVP in some of the cases suggests a functional origin of the disease, with vegetovascular dystonia, temporary dysfunction of papillary muscles or reversible myocardial dystrophy as provoking factors.