Clinical Study on Accentuated Antagonism in the Regulation of Heart Rate in Children.

概要

論文の詳細を見る
Facial immersion testing in cold water (<4deg:C) was performed to study the responses of sinus cycle length to increased parasympathetic tone before and 5min after exercise testing in 27 children. There were no episodes of sinus arrest or extrasystole during the facial immersion testing. The resting sinus cycle lengths were significantly shorter after (539±68msec) than before (597±96msec) exercise testing (p<0.001).The maximal sinus cycle lengths before and after exercise testing during cold water facial immersion testing did not differ significantly (928±167msec and 909±128msec, respectively). Vagal chronotropic responses were calculated from the control sinus cycle lengths and the maximal sinus cycle lengths during facial immersion testing. Facial immersion caused greater prolongation of sinus cyclc length after than before exercisc(73±27% and 54±26%, respectively; p<0.005). We speculate that this augmentation of vagal activity represents accentuated antagonism in these children, i. e., the same parasympathetic stimulus causes a greater response in the presence of a stronger background sympathetic activity.
International Heart Journal刊行会の論文