Right ventricular responses to vagus stimulation of fibers to discrete cardiac regions in dog hearts

Nakano, Hirofumi; Furukawa, Yoshiko; Inoue, Yasurou; Sawaki, Shoji; Oguchi, Takeshi; Chiba, Shigetoshi

doi:10.1016/s0165-1838(98)00156-8

Cited by 5 publications

(5 citation statements)

References 23 publications

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“…Ali et al (1) reported that stimulating the right atrial ventral ganglionated plexus in dogs resulted in slowing of VR during supraventricular tachycardia, along with an improvement in arterial and LV pressures. In this study, the nerve stimulation affected the sinus nodal and possibly other regions of the heart besides the AVN (22). Until now, no complete study of the systemic hemodynamic effects produced by selective AVN parasympathetic stimulation during AF has been reported.…”

Section: Discussionmentioning

confidence: 70%

Selective AV nodal vagal stimulation improves hemodynamics during acute atrial fibrillation in dogs

Wallick

Zhang

Tabata

et al. 2001

American Journal of Physiology-Heart and Circulatory Physiology

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Although the atrioventricular node (AVN) plays a vital role in blocking many of the atrial impulses from reaching the ventricles during atrial fibrillation (AF), a rapid irregular ventricular rate nevertheless persists. The goals of the present study were to explore the feasibility of novel epicardial selective vagal nerve stimulation for slowing of the ventricular rate during AF and to characterize the hemodynamic benefits in vivo. Electrophysiological-echocardiographic experiments were performed on 11 anesthetized open-chest dogs. Hemodynamic measurements were performed during three distinct periods: 1) sinus rate, 2) AF, and 3) AF with vagal nerve stimulation. AF was associated with significant deterioration of all measured parameters (P < 0.025). The vagal nerve stimulation produced slowing of the ventricular rate, significant reversal of the pressure and contractile indexes (P < 0.025), and a sharp reduction in one-half of the abortive ventricular contractions. The present study provides comprehensive evidence that slowing of the ventricular rate during AF by selective ganglionic stimulation of the vagal nerves that innervate the AVN successfully improved the hemodynamic responses.

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Section: Discussionmentioning

confidence: 70%

Selective AV nodal vagal stimulation improves hemodynamics during acute atrial fibrillation in dogs

Wallick

Zhang

Tabata

et al. 2001

American Journal of Physiology-Heart and Circulatory Physiology

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“…These results, therefore, suggest that one-half of the parasympathetic ganglionic cells controlling the right atrial contractility exist in the SAPS locus and SVC-Ao fat pad, and there may be no selective cluster of the intracardiac parasympathetic ganglia for the control of atrial contractile force in the dog heart. There are many clusters of the ganglionic cells in the dog heart (2, 24), but AVPS or stimulation of the clusters of the ganglionic cells at the AV fat pad did not affect the right atrial contractility in the anesthetized dog (14). Cardiac responses to vagus stimulation are also regulated by intracardiac and extracardiac neural regulation in the dog heart (11).…”

Section: Discussionmentioning

confidence: 99%

Inotropic, chronotropic, and dromotropic effects mediated via parasympathetic ganglia in the dog heart

Tsuboi

Furukawa

Nakajima

et al. 2000

American Journal of Physiology-Heart and Circulatory Physiology

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Some parasympathetic ganglionic cells are located in the epicardial fat pad between the medial superior vena cava and the aortic root (SVC-Ao fat pad) of the dog. We investigated whether the ganglionic cells in the SVC-Ao fat pad control the right atrial contractile force, sinus cycle length (SCL), and atrioventricular (AV) conduction in the autonomically decentralized heart of the anesthetized dog. Stimulation of both sides of the cervical vagal complexes (CVS) decreased right atrial contractile force, increased SCL, and prolonged AV interval. Stimulation of the rate-related parasympathetic nerves to the sinoatrial (SA) node (SAPS) increased SCL and decreased atrial contractile force. Stimulation of the AV conduction-related parasympathetic nerves to the AV node prolonged AV interval. Trimethaphan, a ganglionic nicotinic receptor blocker, injected into the SVC-Ao fat pad attenuated the negative inotropic, chronotropic, and dromotropic responses to CVS by 33 approximately 37%. On the other hand, lidocaine, a sodium channel blocker, injected into the SVC-Ao fat pad almost totally inhibited the inotropic and chronotropic responses to CVS and partly inhibited the dromotropic one. Lidocaine or trimethaphan injected into the SAPS locus abolished the inotropic responses to SAPS, but it partly attenuated those to CVS, although these treatments abolished the chronotropic responses to SAPS or CVS. These results suggest that parasympathetic ganglionic cells in the SVC-Ao fat pad, differing from those in SA and AV fat pads, nonselectively control the atrial contractile force, SCL, and AV conduction partially in the dog heart.

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“…The evidence reviewed above supports the notion of specialised functional organisation within the terminal parasympathetic innervation of the heart. This is reflected in the central nervous organisation of the vagal motor nuclei in the medulla and parallel functional pathways of the preganglionic neurones projecting to specific cardiac loci including the ventricles (Randall et al 1986 a , b ; Pardini et al 1987; Billman et al 1989; Nakano et al 1998; Dickerson et al 1998; Sampaio et al 2003; Cheng et al 2004).…”

Section: The Central Regulation Of Cardiac Vagal Neuronesmentioning

confidence: 99%

“…On the contrary, Gatti et al (1997) have demonstrated that cervical vagus nerve stimulation can reduce left ventricle contractility by around 20% in anaesthetised cats in which the heart is paced and the sympathetic influence prevented by β adrenoreceptor blockade. Similarly, Nakano et al (1998) measured changes in the right heart and showed that cervical vagus stimulation decreased d P /d t of right atrium and right ventricle in autonomically decentralised paced hearts of anaesthetised dogs. This seemingly direct action was given a more convincing basis by a study also in dogs (Xenopoulos & Applegate, 1994).…”

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confidence: 91%

Myths and realities of the cardiac vagus

Coote

2013

The Journal of Physiology

159

132

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There is continuing belief that cardiac parasympathetic postganglionic fibres are sparse or absent from the ventricles. This review of the literature shows that the supposition is a myth. Early studies considered that fine silver-stained fibres coursing amongst ventricle myocardial cells were most likely cardiac parasympathetic postganglionic fibres. The conclusions were later supported by acetyl cholinesterase staining using a method that appeared not to be associated with noradrenaline nerve fibres. The conclusion is critically examined in the light of several recent histological studies using the acetyl cholinesterase method and also a more definitive technique (CHAT), that suggest a widespread location of parasympathetic ganglia and a relatively dense parasympathetic innervation of ventricular muscle in a range of mammals including man. The many studies demonstrating acetylcholine release in the ventricle on vagal nerve stimulation and a high density of acetylcholine M 2 receptors is in accord with this as are tests of ventricular performance from many physiological studies. Selective control of cardiac functions by anatomically segregated parasympathetic ganglia is discussed. It is argued that the influence of vagal stimulation on ventricular myocardial action potential refractory period, duration, force and rhythm is evidence that vagal fibres have close apposition to myocardial fibres. This is supported by clear evidence of accentuated antagonism between sympathetic activity and vagal activity in the ventricle and also by direct effects of vagal activity independent of sympathetic activity. The idea of differential control of atrial and ventricular physiology by vagal C and vagal B preganglionic fibres is examined as well as differences in chemical phenotypes and their function. The latter is reflected in medullary and supramedullary control. Reference is made to the importance of this knowledge to understanding the normal physiology of cardiac autonomic control and significance to pathology.

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Right ventricular responses to vagus stimulation of fibers to discrete cardiac regions in dog hearts

Cited by 5 publications

References 23 publications

Selective AV nodal vagal stimulation improves hemodynamics during acute atrial fibrillation in dogs

Selective AV nodal vagal stimulation improves hemodynamics during acute atrial fibrillation in dogs

Inotropic, chronotropic, and dromotropic effects mediated via parasympathetic ganglia in the dog heart

Myths and realities of the cardiac vagus

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