Abstract
Changes in ECG R-R intervels (RR) and blood pressure were assessed by the autoregressive power spectral analysis method in a bronchial asthma patient (severe type: nine years old boy). We studied that there were two spontaneous oscillations of RR and blood pressure. Low frequency (LF: less than 0.1cycle/beat) fluctuations of RR are known to be mediated by the parasympathetic and β-adrenergic nervous system, while high frequency (HF: 0.1-0.5cycle/beat) are mediated by the parasympathetic nervous system. And LF fluctuations of systolic blood pressure (SYS) are mediated by the α-adrenergic nervous system.
In this case, LF power of RR decreased, while HF power of RR and LF power of SYS increased at severe attack. The results suggested that β-adrenergic nervous system activity decreased and α-adrenergic and parasympathetic nervous system activity increased in asthma attack.
