Abstract
Objective: To determine whether signs of cardiac sympathetic activation (together with vagal withdrawal) can be observed in the autonomic balance modulating the sino-atrial node as early as the initial levels of a graded light dynamic exercise. Patients and methods: We studied 15 healthy ambulant subjects (mean±SD age 32±9 years; systolic/diastolic blood pressure 120± 19/77±7mmHg; heart rate 65±9 beats/min), who underwent a control recording of 10 min, followed by a three-step progressive (10, 20 and 30% of nominal maximum for age and sex) supine bicycle exercise. Spectral and cross-spectral analysis of RR and systolic arterial pressure variabilities were used to obtain non-invasive markers of the autonomic adjustments to exercise. Results: The low-frequency component of RR interval variability (which, in normalized units, is a marker of sympathetic modulation of the sino-atrial (SA) node) was progressively increased during all three stages of bicycle exercise. No significant changes were observed in the low-frequency component of systolic arterial pressure variability (i.e. a marker of sympathetic drive to the vasculature) in the early stages of exercise, while a significant increase was observed at 30% of maximum. The index a (which provides a measure of the gain of the arterial pressure-heart period baroreflex) was progressively reduced during all three stages of exercise. Conclusions: While the sympathovagal balance modulating the SA node is immediately shifted towards sympathetic predominance (and vagal withdrawal), markers of peripheral vascular sympathetic activation appear increased only when 30% of maximum exercise is attained.
| Original language | English |
|---|---|
| Pages (from-to) | 1660-1663 |
| Number of pages | 4 |
| Journal | Journal of Hypertension |
| Volume | 13 |
| Issue number | 12 |
| Publication status | Published - 1995 |
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Keywords
- Autonomic nervous system
- Baroreflex
- Computer analysis
- Exercise
- Sympathetic activity
- Vagal activity
ASJC Scopus subject areas
- Physiology
- Cardiology and Cardiovascular Medicine
- Internal Medicine
- Endocrinology
Cite this
Analysis of initial autonomic adjustments to moderate exercise in humans. / Lucini, Daniela; Trabucchi, Vittorio; Malliani, Alberto; Pagani, Massimo.
In: Journal of Hypertension, Vol. 13, No. 12, 1995, p. 1660-1663.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Analysis of initial autonomic adjustments to moderate exercise in humans
AU - Lucini, Daniela
AU - Trabucchi, Vittorio
AU - Malliani, Alberto
AU - Pagani, Massimo
PY - 1995
Y1 - 1995
N2 - Objective: To determine whether signs of cardiac sympathetic activation (together with vagal withdrawal) can be observed in the autonomic balance modulating the sino-atrial node as early as the initial levels of a graded light dynamic exercise. Patients and methods: We studied 15 healthy ambulant subjects (mean±SD age 32±9 years; systolic/diastolic blood pressure 120± 19/77±7mmHg; heart rate 65±9 beats/min), who underwent a control recording of 10 min, followed by a three-step progressive (10, 20 and 30% of nominal maximum for age and sex) supine bicycle exercise. Spectral and cross-spectral analysis of RR and systolic arterial pressure variabilities were used to obtain non-invasive markers of the autonomic adjustments to exercise. Results: The low-frequency component of RR interval variability (which, in normalized units, is a marker of sympathetic modulation of the sino-atrial (SA) node) was progressively increased during all three stages of bicycle exercise. No significant changes were observed in the low-frequency component of systolic arterial pressure variability (i.e. a marker of sympathetic drive to the vasculature) in the early stages of exercise, while a significant increase was observed at 30% of maximum. The index a (which provides a measure of the gain of the arterial pressure-heart period baroreflex) was progressively reduced during all three stages of exercise. Conclusions: While the sympathovagal balance modulating the SA node is immediately shifted towards sympathetic predominance (and vagal withdrawal), markers of peripheral vascular sympathetic activation appear increased only when 30% of maximum exercise is attained.
AB - Objective: To determine whether signs of cardiac sympathetic activation (together with vagal withdrawal) can be observed in the autonomic balance modulating the sino-atrial node as early as the initial levels of a graded light dynamic exercise. Patients and methods: We studied 15 healthy ambulant subjects (mean±SD age 32±9 years; systolic/diastolic blood pressure 120± 19/77±7mmHg; heart rate 65±9 beats/min), who underwent a control recording of 10 min, followed by a three-step progressive (10, 20 and 30% of nominal maximum for age and sex) supine bicycle exercise. Spectral and cross-spectral analysis of RR and systolic arterial pressure variabilities were used to obtain non-invasive markers of the autonomic adjustments to exercise. Results: The low-frequency component of RR interval variability (which, in normalized units, is a marker of sympathetic modulation of the sino-atrial (SA) node) was progressively increased during all three stages of bicycle exercise. No significant changes were observed in the low-frequency component of systolic arterial pressure variability (i.e. a marker of sympathetic drive to the vasculature) in the early stages of exercise, while a significant increase was observed at 30% of maximum. The index a (which provides a measure of the gain of the arterial pressure-heart period baroreflex) was progressively reduced during all three stages of exercise. Conclusions: While the sympathovagal balance modulating the SA node is immediately shifted towards sympathetic predominance (and vagal withdrawal), markers of peripheral vascular sympathetic activation appear increased only when 30% of maximum exercise is attained.
KW - Autonomic nervous system
KW - Baroreflex
KW - Computer analysis
KW - Exercise
KW - Sympathetic activity
KW - Vagal activity
UR - http://www.scopus.com/inward/record.url?scp=0029560107&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029560107&partnerID=8YFLogxK
M3 - Article
C2 - 8903628
AN - SCOPUS:0029560107
VL - 13
SP - 1660
EP - 1663
JO - Journal of Hypertension
JF - Journal of Hypertension
SN - 0263-6352
IS - 12
ER -