RT-233
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Heart rate variability in
essential hypertension. Assessment by heart rate spectral analysis
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Gaetano Diricatti, Vincenzo
Cupelli*, Paolo Manetti, Loira Toncelli, Bruno Cappelli, Giorgio Galanti**, Gian Franco
Gensini.
*Istituto di Medicina del Lavoro, **Scuola di Medicina Sportiva, Istituto di
Clinica Medica Generale e Cardiologia, Universita di Firenze, Italy
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Abstract
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Background. Effective treatment of
hypertension includes decrease of blood pressure at rest, during dynamic and isometric
exercise. A large number of studies indicate that aerobic exercise training lowers blood
pressure both at rest and during dynamic exercise in hypertensives. Results of the
mechanisms responsible for the hypotensive effect of physical training are conflicting: a
change in sympatho-vagal activity is most likely involved.
The aim of the present study was to examine the effect of regular exercise on the
autonomic nervous activity in essential hypertensives by means of power spectral analysis
of heart rate variability.
Methods. Twelve male borderline hypertensive athletes (group A) (aged
31-56 yr) who had been performing 4 hours of jogging per week for at least 1 year, were
evaluated at rest and both during isometric (handgrip) and dynamic cycle-ergometer stress
test (75 watt load). They were compared both with 10 age-matched normotensive endurance
athletes (group B) and 8 sedentary hypertensives (group C).
Results. Power spectral analysis of heart rate variability
demonstrated that the autonomic nervous response in group A was similar to that in group B
at rest and during dynamic exercise stress test (rest: LC:\WWW 0.267 ± 0.01 vs 0.261 ± 0.03
nu, p = ns, HC:\WWW 0.210 ± 0.04 vs 0.218 ± 0.07 nu, p = ns; dynamic exercise stress test-75
watt: LC:\WWW 0.351 ± 0.03 vs 0.345 ± 0.01 nu, ns, HC:\WWW 0.091 ± 0.001 vs 0.088 ± 0.001 nu,
p = ns) but different from that in group C (rest: LC:\WWW 0.325 ± 0.05 nu, group A vs group
C: p < 0.05, HC:\WWW 0.200 ± 0.01, p = ns; dynamic exercise stress test-75 watt: LC:\WWW 0.472
± 0.001 nu, group A vs group C: p < 0.001, HC:\WWW 0.121 ± 0.002, group A vs group C: p
< 0.05). On the other hand, during isometric exercise group A still showed a pattern of
behavior similar to that of group C (LC:\WWW 0.298 ± 0.01 vs 0.319 ± 0.01 nu, p = ns; HC:\WWW
0.177 ± 0.03 vs 0.179 ± 0.02 nu, p = ns) but different from that of group A (LC:\WWW 0.472
± 0.02 nu; group A vs group B: p < 0.05; HC:\WWW 0.066 ± 0.05 nu; group A vs group B: p
< 0.01).
Conclusions. Endurance training does affect the autonomic response to
dynamic exercise but not to isometric exercise in hypertensive subjects.
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Key Words
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Heart rate variability
essential hypertension, heart rate spectral analysis, aerobic exercise training,
sympatho-vagal activity, dynamic exercise, isometric exercise, hypotensive effect of
exercise training, OA
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