Comparison of cardiac and gastric responses to vagal stimulation in hypertensive women.
BACKGROUND
The aim was to evaluate the interactions between the effects of vagal stimulation by sham feeding (nonbaroreflex) and deep breathing (baroreflex) on heart rate variability (HRV) and gastric myoelectrical activity (GMA) in pre- and postmenopausal women with essential hypertension.


METHODS
One hundred five post- and premenopausal women with hypertension and 60 premenopausal normotensive women were observed. The study protocol consisted of 5 min of resting HRV followed by 5 min of deep breathing (DB), then 6 min of sham feeding (SF) with 30-min electrogastrography (EGG) before and after SF. The fasting plasma level of noradrenalin was measured.


RESULTS
The HRV parameter values at rest in the hypertensive group were half those in the control group (p<0.05). There were notably higher HRV parameter values in the premenopausal women. Plasma noradrenalin level was higher in the postmenopausal women (p=0.0009). The effect of DB was similar before and after menopause; however, HRV parameters in response to DB were lower in the hypertensive women than in the controls (p<0.05). In the controls there was a marked increase in the main HRV parameters in response to DB. In fasting electrogastrography the lowest normogastria percentage was observed in the postmenopausal women. EGG showed that only SF significantly affected the period dominant power (PDP) in all groups and the bradygastria percentage in the postmenopausal women.


CONCLUSIONS
This study suggests that the interactions that occur between the effects of non-baroreflex and baroreflex vagal stimulation in hypertensive women may contribute to gastric motility disorders and dyspeptic symptoms.
Department of Pathophysiology, Institute of Cardiology, Medical College, Jagiellonian University, Cracow, Poland.
Piotr J
PJ
Thor
Agata
A
Furgała
Marcel
M
Mazur
Aneta
A
Pośnik-Urbańska
Władysława
W
Kolasińska-Kloch
Danuta
D
Czarnecka
Kalina
K
Kawecka-Jaszcz
D004576:Electromyography; D055724:Electrophysiological Phenomena / Q000502:physiology; D005215:Fasting / Q000097:blood / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D010812:Physical Stimulation; D012119:Respiration; D013270:Stomach / Q000503:physiopathology*; D013997:Time Factors; D014630:Vagus Nerve / Q000503:physiopathology*
D009638:Norepinephrine