[Computerized cardiac rhythm and heart analysis in children with mitral valve prolapse (author's transl)].

Twenty-nine children with echocardiographically-proven mitral valve prolapse (MVP) were studied by means of exercise-ECG testing, and continuous ECG monitoring. ECG's were stored on tape and compared with those of 20 healthy children. The frequency of supra- and ventricular premature beats (VPB) and the response of heart rate and RR intervals over the length of time ("tachogram") were graphed and analyzed by various algorithms. Of the children with MVP, one required treatment for his arrhythmia. A total of 16 children with MVP ( = 55%) had various rhythm disturbances. VPB's were observed in one child in the routine ECG, in four children during exercise testing, and in nine only during continuous ECG monitoring, whereas only 9% of the healthy children were found to display VPB's. Differences could also be seen in the tachogram readings: 22 ( = 76%) MVP children were characterized by a wide variation of RR intervals, suggesting a pronounced sympathetic reactivity, twelve ( = 60%) healthy and six ( = 23%) MVP children showed a narrow, oscillating tachogram trace. Although the syndrome is already present in childhood, it must be seen as progredient, manifesting itself in the frequency and gravity of arrhythmias.