Articles: vagus-nerve-physiopathology.
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Randomized Controlled Trial
Islet-cell dysfunction induced by glucocorticoid treatment: potential role for altered sympathovagal balance?
Glucocorticoids impair glucose tolerance by inducing insulin resistance. We investigated the dose-dependent effects of glucocorticoid treatment on islet-cell function in healthy males and studied the role of the autonomic nervous system. ⋯ We conclude that in addition to inducing insulin resistance, prednisolone treatment dose-dependently impaired islet-cell function. Altered sympathovagal balance may be related to these effects.
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We studied the effects of transcutaneous electrical stimulation at the tragus, the anterior protuberance of the outer ear, for inhibiting atrial fibrillation (AF). ⋯ LL-TS can reverse RAP-induced atrial remodeling and inhibit AF inducibility, suggesting a potential noninvasive treatment of AF.
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Comparative Study
Autonomic nerve activity and the short-term variability of the Tpeak-Tend interval in dogs with pacing-induced heart failure.
In congestive heart failure (CHF), autonomic nervous system (ANS) activity is known to modulate arrhythmic risk through its effects on myocardial repolarization. An increased interval between the peak and the end of the T wave (T(peak)-T(end)) has been reported to increase the incidence of sudden cardiac death. However, the ANS influence on the T(peak)-T(end) interval remains unclear. ⋯ In a canine model of pacing-induced CHF, iSGNA correlates positively while iVNA correlates negatively with T(peak)-T(end)STV(T). These findings suggest that SGNA increases while VNA decreases the dispersion of ventricular repolarization in ambulatory dogs with CHF.
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Cardiovascular research · Sep 2012
Cardioprotection evoked by remote ischaemic preconditioning is critically dependent on the activity of vagal pre-ganglionic neurones.
Innate mechanisms of inter-organ protection underlie the phenomenon of remote ischaemic preconditioning (RPc) in which episode(s) of ischaemia and reperfusion in tissues remote from the heart reduce myocardial ischaemia/reperfusion injury. The uncertainty surrounding the mechanism(s) underlying RPc centres on whether humoral factor(s) produced during ischaemia/reperfusion of remote tissue and released into the systemic circulation mediate RPc, or whether a neural signal is required. While these two hypotheses may not be incompatible, one approach to clarify the potential role of a neural pathway requires targeted disruption or activation of discrete central nervous substrate(s). ⋯ These data indicate a crucial dependence of RPc cardioprotection against ischaemia/reperfusion injury upon the activity of a distinct population of vagal pre-ganglionic neurones.
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Bmc Cardiovasc Disor · Jan 2012
Body mass index contributes to sympathovagal imbalance in prehypertensives.
The present study was conducted to assess the nature of sympathovagal imbalance (SVI) in prehypertensives by short-term analysis of heart rate variability (HRV) to understand the alteration in autonomic modulation and the contribution of BMI to SVI in the genesis of prehypertension. ⋯ It was concluded that autonomic imbalance in prehypertensives manifested in the form of increased sympathetic activity and vagal inhibition. In prehypertensives with higher BMI, vagal withdrawal was predominant than sympathetic overactivity. Magnitude of SVI (alteration in LF-HF ratio) was linked to changes in BMI and DBP. BMI had an independent influence on LF-HF ratio. It was advised that life-style modifications such as yoga and exercise would enable achieve the sympathovagal balance and blood pressure homeostasis in prehypertensives.