Heart rate spectral ana~sis in asthma Research Paper
Clinical Autonomic Research 2, 105--111 (1992)
SYMPATHETIC and parasympathetic activity was evaluated
Spectral analysis of heart rate variability in bronchial asthma
in ten healthy controls, nine asymptomatic, untreated asthmatic subjects and ten asthmatic patients during treatment for acute asthma, by measurement of the variation in resting heart rate using frequency spectrum analysis. Heart rate was recorded by ECG and respiratory rate by impedance plethysmography. Spectral density of the beatto-beat heart rate was measured within the low frequency band 0.04 to 0.10 Hz (low frequency power) modulated by sympathetic and parasympathetic activity, and within a 0.12 Hz band width at the respiratory frequency mode (respiratory frequency power) modulated by parasympathetic activity. Acute asthmatics had higher heart rates than either of the other two groups; this was probably related to the effects of beta-adrenoceptor agonist medica-
tion. Sympathetically mediated heart rate variability (normalized low frequency power) was significantly lower in both asymptomatic (p < 0.002) and acute (dO< 0.02) asthma subjects compared to controls. This is consistent with altered sympathetic/parasympathetic regulation of heart rate in subjects with bronchial asthma.
C h r i s t o p h e r S. Garrard, FRCP, DPhil %z'cA, A n d r e a s Seidler, M D 2, A n d r e w M c K i b b e n , BS 2, Laura E. i c A I p i n e , BA 3 and David Gordon, MD, PhD3 1The Intensive Therapy Unit, John Radcliffe Hospital, Oxford OX3 9DU, UK; The Departments of 2Medicine, and 3pediatrics, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA.
CACorresponding Author
Key words: Asthma, Heart rate variability, Spectral analysis, Respiration, Autonomicnervous system, Adrenergic receptors
Introduction The precise role of the autonomic nervous system in the pathogenesis of bronchial asthma continues to be actively debated with hypotheses based upon increased alpha-adrenergic receptor sensitivity, 1-s decreased beta-adrenergic sensitivity, 6 circulating catecholamines, 7-9 increased vagal tonus, 1° and more recently the role of the non-adrenergic non-cholinergic system] 1 The resolution of this question has been hindered by the lack of a suitable, non-invasive, direct measure of autonomic nervous system output. However, it has been possible to evaluate autonomic nervous system activity, in both human and animal models, by analysis of the beat-to-beat variability of heart rate] 2
Clinical Autonomic Research 2, 105--111 (1992)
SYMPATHETIC and parasympathetic activity was evaluated
Spectral analysis of heart rate variability in bronchial asthma
in ten healthy controls, nine asymptomatic, untreated asthmatic subjects and ten asthmatic patients during treatment for acute asthma, by measurement of the variation in resting heart rate using frequency spectrum analysis. Heart rate was recorded by ECG and respiratory rate by impedance plethysmography. Spectral density of the beatto-beat heart rate was measured within the low frequency band 0.04 to 0.10 Hz (low frequency power) modulated by sympathetic and parasympathetic activity, and within a 0.12 Hz band width at the respiratory frequency mode (respiratory frequency power) modulated by parasympathetic activity. Acute asthmatics had higher heart rates than either of the other two groups; this was probably related to the effects of beta-adrenoceptor agonist medica-
tion. Sympathetically mediated heart rate variability (normalized low frequency power) was significantly lower in both asymptomatic (p < 0.002) and acute (dO< 0.02) asthma subjects compared to controls. This is consistent with altered sympathetic/parasympathetic regulation of heart rate in subjects with bronchial asthma.
C h r i s t o p h e r S. Garrard, FRCP, DPhil %z'cA, A n d r e a s Seidler, M D 2, A n d r e w M c K i b b e n , BS 2, Laura E. i c A I p i n e , BA 3 and David Gordon, MD, PhD3 1The Intensive Therapy Unit, John Radcliffe Hospital, Oxford OX3 9DU, UK; The Departments of 2Medicine, and 3pediatrics, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA.
CACorresponding Author
Key words: Asthma, Heart rate variability, Spectral analysis, Respiration, Autonomicnervous system, Adrenergic receptors
Introduction The precise role of the autonomic nervous system in the pathogenesis of bronchial asthma continues to be actively debated with hypotheses based upon increased alpha-adrenergic receptor sensitivity, 1-s decreased beta-adrenergic sensitivity, 6 circulating catecholamines, 7-9 increased vagal tonus, 1° and more recently the role of the non-adrenergic non-cholinergic system] 1 The resolution of this question has been hindered by the lack of a suitable, non-invasive, direct measure of autonomic nervous system output. However, it has been possible to evaluate autonomic nervous system activity, in both human and animal models, by analysis of the beat-to-beat variability of heart rate] 2
