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Spectral change in heart rate variability in response to mental arithmetic before and after the beta-adrenoceptor
A Moriguchi1, A Otsuka, K Kohara
1Department of Geriatric Medicine, Osaka University Medical School, Japan.
Insights
Mental stress elevates blood pressure via sympathetic nervous system activation. Carteolol, a beta-blocker, mitigates this by modulating autonomic responses to stress.
Area of Science:
- Cardiology
- Neuroscience
- Pharmacology
Background:
- Mental stress impacts cardiovascular function through neural regulatory mechanisms.
- Sympathetic nervous system activity is a key mediator of hemodynamic changes during stress.
- Beta-adrenoceptor blockers influence autonomic responses to physiological challenges.
Purpose of the Study:
- To investigate the neural regulatory mechanisms of hemodynamic changes induced by mental stress.
- To evaluate the effect of carteolol, a non-selective beta-adrenoceptor-blocker, on autonomic responses to mental stress.
- To analyze heart rate fluctuation using spectral analysis before and after carteolol administration.
Main Methods:
- Spectral analysis of heart rate variability was performed.
- Hemodynamic parameters (blood pressure, heart rate) were measured.
- Participants underwent mental stress tests before and after carteolol administration.
Main Results:
- Mental stress increased blood pressure and heart rate, with elevated low frequency (LF) and LF/HF ratio, indicating increased sympathetic activity.
- Carteolol did not alter baseline cardiovascular measurements.
- Carteolol attenuated the pressor response to mental stress, decreasing LF and LF/HF components and increasing the high frequency (HF) component.
Conclusions:
- Mental stress activates the sympathetic nervous system, leading to elevated blood pressure.
- Beta-adrenoceptor blockade with carteolol attenuates the pressor response to mental stress.
- Carteolol modulates autonomic responses, suggesting a role in managing stress-induced hypertension.
Abstract:
Spectral analysis of heart rate fluctuation was evaluated before and after administration of carteolol, a non-selective beta-adrenoceptor-blocker, to investigate the neural regulatory mechanisms underlying the haemodynamic changes induced by mental stress. Mental stress increased blood pressure and heart rate, with an increased low frequency band, and low frequency/high frequency ratio of the power spectral analysis which are indices of sympathetic activity. Carteolol did not change basal and pre-mental stress measurements of blood pressure, heart rate and spectral density. However, carteolol altered the response to mental stress with a decrease in spectral density of the low frequency band and low frequency/high frequency ratio, and an increase in the high frequency component. These results confirm that mental stress elevates blood pressure by activating the sympathetic nervous system, and suggest that blockade of the beta-adrenoceptor attenuates the pressor response by preventing the autonomic responses to mental stress.