Relationship between Anamnestically Assessed Physical Activity and Baroreflex Sensitivityafter Anthracycline

Overview

In the submitted study the authors evaluated the effect of regular physical activity on the development ofautonomous regulation of the circulation in children who had previously treatment on account of a malignanttumour, in particular leukaemia, and were treated with cardiotoxic anthracyclines.In 22 children (9 - 21) with a history of leukaemia the authors recorded by non-invasive methods the pulserateat rest, pulse intervals (PI), systolic (BPs) and diastolic (BPd) blood pressure and calculated the baroreflexsensitivity of the heart (BRS in ms*mmHg -1 , BRSf in Hz*mmHg -1 ). The childrens physical activity was assessedfor one month by means of questionnaires and the approximate value of expended energy was expressed inkJ/kg/day. The authors calculated mean values, standard deviations and mutual correlation coefficients of thesevariables: age, TI, BPs, BPd, BRS, BRSf, body weight, height, energy expenditure in kJ/kg/day and the body massindex, BMI. By regression analysis they assessed the statistical significance of difference in the development ofdifferent circulatory parameters and indices of somatic development with regard to age and therapeutic procedurein children treated with anthracyclines and those not treated with anthracyclines.The rise of BPs and BPd correlates with age, it does not correlate with the mean physical load. The mean lengthof TI correlates with age and the mean physical load. BRS correlates with TI, BRSf correlates with BMI. In thegroup of children treated with anthracyclines there is a more rapid prolongation of TI, rise of BRS, but a slowerrise of BPs, BPd, body weight, BMI and physical activity as compared with the group not treated with anthracyc-lines. The trend of BRSf is not influenced by anthracyclines.Anthracycline treatment interferes with the development of cardiovascular functions. The more rapid prolon-gation of TI and the slower rise of BP with age in these children is not associated with regular physical activity.

Key words:
leukaemia, anthracycline therapy, baroreflex, physical activity