Electrophysiological-anatomic correlates of ATP-triggered vagal reflex in dogs. II. Vagal afferent traffic

1994 ◽  
Vol 267 (3) ◽  
pp. H1093-H1097 ◽  
Author(s):  
C. M. Hurt ◽  
L. Wang ◽  
J. Xu ◽  
W. Sterious ◽  
A. Pelleg
Keyword(s):  
Sinus Node ◽  
Canine Model ◽  
Right Atrial ◽  
Vagus Nerves ◽  
C Fiber ◽  
Study Support ◽  
Vagal Reflex ◽  
The Right ◽  
Depressor Reflex ◽  
Left Vagus

Extracellular ATP can act on chemosensitive vagal C-fiber nerve terminals in the lungs, thereby eliciting a pulmonary-cardiac depressor reflex. Previous studies have shown a right vagal dominance in afferent traffic elicited by intra-right atrial ATP. To elucidate the mechanism of this phenomenon, the following hypotheses were tested in a canine model. 1) Intra-right and intra-left pulmonary ATP elicit neural afferent traffic, which travels via the right and left vagus nerves, respectively. 2) Intra-right vs. intra-left pulmonary ATP causes similar suppression of sinus node automaticity. Data obtained in this study support both hypotheses and suggest that right vagal dominance in afferent neural traffic elicited by ATP is probably due to the action of ATP and/or its metabolites on nonpulmonary tissues.

Electrophysiological-anatomic correlates of ATP-triggered vagal reflex in dogs

1993 ◽  
Vol 265 (2) ◽  
pp. H681-H690 ◽  
Author(s):  
A. Pelleg ◽  
C. M. Hurt ◽  
J. M. Soler-Baillo ◽  
M. Polansky
Keyword(s):  
Vagus Nerve ◽  
Sinus Node ◽  
Right Atrial ◽  
Pacemaker Activity ◽  
Dependent Manner ◽  
Vagus Nerves ◽  
Experimental Conditions ◽  
C Fiber ◽  
Vagal Reflex ◽  
The Right

To test the hypothesis that afferent traffic of the ATP-triggered vagal reflex travels mainly in the right vagus nerve, we quantitated the response of the sinus node pacemaker activity and atrioventricular (AV) nodal conduction to increasing doses of intra-atrial ATP under baseline conditions, in the presence of aminophylline, and subsequently after either right followed by left cervical vagotomy or vice versa. In addition, the effect of right vagal C-fiber afferent blockade on the action of ATP in the sinus node was also determined. Because vagal efferent traffic to the sinus and AV nodes travels mainly via the right and left vagus nerves, respectively, the working hypothesis predicted that left vagotomy would have a much smaller effect than right vagotomy on the negative chronotropic action of ATP in the sinus node and predicted similar effects of left vs. right vagotomy on the negative dromotropic action of ATP on AV nodal conduction. ATP suppressed sinus node automaticity and AV nodal conduction in a dose-dependent manner. The attenuation of the action of ATP on the sinus node by right vagotomy was much more pronounced than that caused by left vagotomy, while the negative dromotropic action of ATP in the AV node was similarly attenuated by right vs. left vagotomy. In addition, sinus node automaticity, which was only mildly attenuated by left vagotomy, was markedly suppressed by right vagal C-fiber afferent blockade. It was concluded that in the dog, afferent vagal traffic triggered by intra-right atrial ATP travels under these experimental conditions mainly via the right vagus nerve.

Pulmonary C-fibers reflexly increase secretion by tracheal submucosal glands in dogs

1985 ◽  
Vol 58 (3) ◽  
pp. 907-910 ◽  
Author(s):  
H. D. Schultz ◽  
A. M. Roberts ◽  
C. Bratcher ◽  
H. M. Coleridge ◽  
J. C. Coleridge ◽  
...  
Keyword(s):  
Gland Secretion ◽  
Right Atrial ◽  
Vagus Nerves ◽  
C Fibers ◽  
Airway Secretion ◽  
Submucosal Glands ◽  
C Fiber ◽  
Anesthetized Dogs ◽  
The Right ◽  
Stimulation Of

Stimulation of bronchial C-fibers evokes a reflex increase in secretion by tracheal submucosal glands, but the influence of pulmonary C-fibers on tracheal gland secretion is uncertain. In anesthetized dogs with open chests, we sprayed powdered tantalum on the exposed mucosa of a segment of the upper trachea to measure the rate of secretion by submucosal glands. Secretions from the gland ducts caused elevations (hillocks) in the tantalum layer. We counted hillocks at 10-s intervals for 60 s before and 60 s after we injected capsaicin (10–20 micrograms/kg) into the right atrium to stimulate pulmonary C-fiber endings. Right atrial injection of capsaicin increased the rate of hillock formation fourfold, but left atrial injection had no significant effect. The response was abolished by cutting the vagus nerves or cooling them to 0 degree C. We conclude that the reflex increase in tracheal submucosal gland secretion evoked by right atrial injection of capsaicin was initiated as capsaicin passed through the pulmonary vascular bed, and hence that pulmonary C-fibers, like bronchial C-fibers, reflexly increase airway secretion.

Effect of canine cardiac nerves on heart rate, rhythm, and pacemaker location

1986 ◽  
Vol 250 (4) ◽  
pp. H630-H644 ◽  
Author(s):  
R. B. Schuessler ◽  
J. P. Boineau ◽  
A. C. Wylds ◽  
D. A. Hill ◽  
C. B. Miller ◽  
...  
Keyword(s):  
Heart Rate ◽  
Right Atrium ◽  
General Trend ◽  
Canine Model ◽  
Right Atrial ◽  
Sympathetic Stimulation ◽  
Open Chest ◽  
Left Posterior ◽  
The Right ◽  
Cardiac Nerves

In open-chest dogs, right- and left-sided cardiac nerves were stimulated to determine their effect on heart rate, rhythm, and pacemaker location. The majority of the nerves produced chronotropic changes; 72% of the induced rhythms originated from within the atrial pacemaker complex. Ten percent of the stimulations produced an atrio-ventricular (AV) nodal rhythm; most of the time this was induced by the left posterior and anterior ansae and ventrolateral nerves. The dominance of a lateral right atrial pacemaker was observed in 8% of the stimulations; the dorsal cardiac and innominate nerves induced this rhythm the majority of the time. The general trend was for a cranial shift in the location of the pacemaker within the pacemaker complex with sympathetic stimulation and a caudal shift with parasympathetic stimulation. Exceptions to the pattern may be explained by the preferential effect of the nerves on the pacemakers in the right atrium. The study demonstrates, in the canine model, that in addition to the sinus and AV nodes, there is a system of pacemakers controlled by the cardiac nerves.

scholarly journals Prolonged Sinus Pauses upon Termination of Paroxysmal Atrial Fibrillation: Abnormal Right Atrial Electrophysiologic and Electroanatomic Findings

2017 ◽  
Vol 44 (2) ◽  
pp. 107-114 ◽  
Author(s):  
Zhengyu Bao ◽  
Hongwu Chen ◽  
Bing Yang ◽  
Michael Shehata ◽  
Weizhu Ju ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Sinus Node ◽  
P Wave ◽  
Right Atrial ◽  
Control Group ◽  
Paroxysmal Supraventricular Tachycardia ◽  
Group A ◽  
Group B ◽  
Activation Times ◽  
The Right

The efficacy of pulmonary vein antral isolation for patients with prolonged sinus pauses (PSP) on termination of atrial fibrillation has been reported. We studied the right atrial (RA) electrophysiologic and electroanatomic characteristics in such patients. Forty patients underwent electroanatomic mapping of the RA: 13 had PSP (group A), 13 had no PSP (group B), and 14 had paroxysmal supraventricular tachycardia (control group C). Group A had longer P-wave durations in lead II than did groups B and C (115.5 ± 15.4 vs 99.5 ± 10.9 vs 96.5 ± 10.4 ms; P=0.001), and RA activation times (106.8 ± 13.8 vs 99 ± 8.7 vs 94.5 ± 9.1 s; P=0.02). Group A's PP intervals were longer during adenosine triphosphate testing before ablation (4.6 ± 2.3 vs 1.7 ± 0.6 vs 1.5 ± 1 s; P <0.001) and after ablation (4.7 ± 2.5 vs 2.2 ± 1.4 vs 1.6 ± 0.8 s; P <0.001), and group A had more complex electrograms (11.4% ± 5.4% vs 9.3% ± 1.6% vs 5.8% ± 1.6%; P <0.001). Compared with group C, group A had significantly longer corrected sinus node recovery times at a 400-ms pacing cycle length after ablation, larger RA volumes (100.1 ± 23.1 vs 83 ± 22.1 mL; P=0.04), and lower conduction velocities in the high posterior (0.87 ± 0.13 vs 1.02 ± 0.21 mm/ms; P=0.02) and high lateral RA (0.89 ± 0.2 vs 1.1 ± 0.35 mm/ms; P=0.04). We found that patients with PSP upon termination of atrial fibrillation have RA electrophysiologic and electroanatomic abnormalities that warrant post-ablation monitoring.

scholarly journals THE INFLUENCE OF THE VAGUS NERVES UPON CONDUCTION BETWEEN AURICLES AND VENTRICLES IN THE DOG DURING AURICULAR FIBRILLATION

1916 ◽  
Vol 24 (5) ◽  
pp. 605-619 ◽  
Author(s):  
G. Canby Robinson
Keyword(s):  
Vagus Nerve ◽  
Vagus Nerves ◽  
The Right ◽  
Left Vagus ◽  
Stimulation Of

The experiments that have been reported indicate that stimulation of either the right vagus or the left vagus nerve is equally effectual in blocking impulses from the auricles to the ventricles when auricular fibrillation is present. Stimulation of the left vagus nerve is as effectual in blocking impulses from the normally beating auricles as from the auricles when in a state of fibrillation, and the type of auricular activity has apparently no influence on the effect which stimulation of the left vagus has on auriculoventricular conduction.

Long-term effects of hyperpolarization-activated inward current blockade on cardiac parasympathetic activity

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
A Scridon ◽  
VB Halatiu ◽  
AI Balan ◽  
DA Cozac ◽  
GV Moldovan ◽  
...  
Keyword(s):  
Heart Rate ◽  
Vagus Nerve ◽  
Vagal Stimulation ◽  
Sinus Node ◽  
Vagal Tone ◽  
Right Atrial ◽  
The Right

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by a grant of the Romanian Ministry of Education and Research, CNCS - UEFISCDI Background The autonomic control of the pacemaker current, If, and the molecular mechanisms underlying parasympathetic If modulation are well understood. Conversely, the effects of chronic If blockade on the parasympathetic nervous system and on the heart rate (HR) response to acute parasympathetic changes are still largely unknown. Such interactions could significantly influence the course of patients undergoing chronic therapy with the If blocker ivabradine. Purpose We aimed to assess the effects of long-term If blockade using ivabradine on cardiac autonomic modulation and on the cardiovascular response to acute in vivo and in vitro parasympathetic stimulation. Methods Radiotelemetry ECG transmitters were implanted in 6 Control and 10 ivabradine-treated male Wistar rats (IVA; 3 weeks, 10 mg/kg/day); sympathetic and parasympathetic heart rate variability parameters were assessed. At the end of the study, the right atrium was removed and right atrial HCN(1-4) RNA expression levels were analyzed. The HR and systolic blood pressure (SBP) responses to in vivo electrical stimulation of the right vagus nerve (2–20 Hz) and the spontaneous sinus node discharge rate (SNDR) response to in vitro cholinergic receptors stimulation using carbamylcholine (10-9–10-6 mol/L) were assessed in 6 additional Control and 10 IVA rats. Results At the end of the study, mean 24-h HR was significantly lower in the IVA compared with the Control rats (301.3 ± 7.5 bpm vs. 341.5 ± 8.3 bpm; p< 0.01). Ivabradine administration led to a significant increase in vagal tone and shifted the sympatho-vagal balance towards vagal dominance (awake, asleep, and over 24-h; all p< 0.05). In the Control rats, in vivo vagus nerve stimulation induced a progressive decrease in both the SBP (p = 0.0001) and the HR (p< 0.0001). Meanwhile, in the IVA rats, vagal stimulation had no effect on the HR (p = 0.16) and induced a significantly lower drop in SBP (p< 0.05). Ivabradine-treated rats also presented a significantly lower SNDR drop in response to carbamylcholine (p< 0.01) and significantly higher HCN4 expression (p = 0.02). Conclusion Long-term If blockade using ivabradine caused a significant increase in vagal tone and shifted the autonomic balance towards vagal dominance in rats. Given the highly proarrhythmic effects of vagal activation at the atrial level, these findings could provide an explanation for the increased risk of atrial fibrillation associated with ivabradine use in clinical trials. In addition, ivabradine reduced the HR response to direct muscarinic receptors stimulation, canceled the cardioinhibitory response and blunted the hemodynamic response to in vivo vagal stimulation, and led to significant sinus node HCN4 up-regulation. These data suggest that ivabradine-induced HCN4 and the consequent If up-regulation could render the sinus node less sensitive to acute vagal inputs and could thus protect against excessive bradycardia induced by acute vagal activation.

scholarly journals Formation of Perioesophageal Plexus Gulae and Anterior and Posterior Vagal Trunks in South Indian Population : A morphological study

2012 ◽  
Vol 01 (01) ◽  
pp. 001-006
Author(s):  
Amudha Govindarajan
Keyword(s):  
Indian Population ◽  
Surgical Repair ◽  
South Indian Population ◽  
Vagus Nerves ◽  
Medical College ◽  
South Indian ◽  
Autopsy Specimens ◽  
Madras Medical College ◽  
The Right ◽  
Left Vagus

Abstract Background and Aim of the study: Vagus the wanderer is the tenth cranial nerve with long extra cranial course. Below the bifurcation of trachea, the right and left vagi form plexus around the oesophagus before they enter the abdomen as anterior and posterior vagal trunks. There are variations in the contribution by the right and left vagi for the formation of oesophageal plexus and according to Chamberlin and Winship there are three different patterns in the formation of peri oesophageal plexus. The present study was aimed to study the formation of perioesophageal plexus, incidence of different patterns of peri oesophageal plexus in south Iudian population and the number of vagal trunks formed from the oesophageal plexus in the lower end of the oesophagus. Materials and Methods : The formation of perioesophageal plexus Gulae was studied in forty four autopsy specimens of oesophagus and stomach and six foetal specimens at Institute of Anatomy, Madras Medical College, Chennai. Results : The formation of perioesophageal plexus and the number of fibres from the right and left vagus nerves which contribute to the plexus formation were studied. There were significant differences in the formation of plexus Gulae. There were variations in the pattern of perioesophageal plexus and the number of vagal trunks arising from the plexus. The results of the present study in South Indian population were compared with the results in the Western population. Conclusions : Awareness regarding the presence of plexus Gulae and number of vagal trunks related to lower end of oesophagus has considerable importance in the surgical repair of hiatus hernia and while treating atrial fibrillation.

Right atrium mediates a vasomotor reflex

1981 ◽  
Vol 241 (3) ◽  
pp. R163-R166
Author(s):  
R. F. Munzner ◽  
D. G. Ward ◽  
D. S. Gann
Keyword(s):  
Right Atrium ◽  
Carotid Arteries ◽  
Right Atrial ◽  
Vagus Nerves ◽  
Vascular Responses ◽  
The Right ◽  
Vasomotor Reflex ◽  
Atrial Receptors ◽  
Volume Pulsation

To examine the role of right atrial receptors in mediating reflex vascular responses we measured, in cats anesthetized with chloralose/urethan, changes in mean arterial pressure (MAP) in response to volume pulsation of the right atrium (+/- 1 ml, 1 Hz). Changes in MAP were measured 1) with pressure in the carotid arteries normal and vagus nerves intact: right atrial pulsation led to a very small and transient fall in MAP; 2) with pressure in the carotid arteries at 75 mmHg and the vagus nerves intact: right atrial pulsation led to a larger and sustained fall in MAP; 3) with pressure in the carotid arteries at 75 mmHg and the vagus nerves cooled or sectioned bilaterally: right atrial pulsation of the right atrium led only to a very small and transient fall in MAP. These data suggest strongly that signals from right atrial receptors traveling in the vagus nerves mediate a reflex change in MAP that is normally masked by signals from carotid receptors.

scholarly journals Arylamine N-acetyltransferase 2 Expression in the Developing Heart

2005 ◽  
Vol 53 (5) ◽  
pp. 583-592 ◽  
Author(s):  
Larissa Wakefield ◽  
Valerie Cornish ◽  
Fiona Broackes-Carter ◽  
Edith Sim
Keyword(s):  
Cardiac Tissue ◽  
Cardiac Development ◽  
Sinus Node ◽  
Circulation Pattern ◽  
Right Atrial ◽  
Developing Heart ◽  
Right Atrial Appendage ◽  
The Right

Murine arylamine N-acetyltransferase 2 (NAT2) is expressed in the developing heart and in the neural tube at the time of closure. Classically described as a xenobiotic metabolizing enzyme, there is increasing evidence for a distinct biological role for murine NAT2. We have characterized the expression of arylamine N-acetyltransferase 2 during cardiogenesis, mapping its expression in vivo, using a lacZ insertion deletion, and also in vitro, by measuring NAT2 enzyme activity. These findings show that cardiac Nat2 expression is both temporally and spatially regulated during development. In neonatal mice, cardiac Nat2 expression is most extensive in the central fibrous body and is evident in the atrioventricular valves and the valves of the great vessels. Whereas Nat2 expression is not detected in ventricular myocardial cells, Nat2 is strongly expressed in scattered cells in the region of the sinus node, the epicardium of the right atrial appendage, and in the pulmonary artery. Expression of active NAT2 protein is maximal when the developing heart attains the adult circulation pattern and moves from metabolizing glucose to fatty acids. NAT2 acetylating activity in cardiac tissue from Nat2−/- and Nat2+/- mice indicates a lack of compensating acetylating activity either from other acetylating enzymes or by NAT2 encoded by the wild-type Nat2 allele in Nat2+/- heterozygotes. The temporal and spatial control of murine Nat2 expression points to an endogenous role distinct from xenobiotic metabolism and indicates that Nat2 expression may be useful as a marker in cardiac development.

scholarly journals INFLUENCE OF PERMANENT PACING OF THE ATRIA FROM UPPER ANTERIOR AREA OF INTERCARDIAC SEPTA (AREA OF BAKHMAN’S FASCICLES) ON THE PART OF AMOTIVATIONAL VENTRICLE STIMULATION

2016 ◽  
Vol 175 (2) ◽  
pp. 12-16
Author(s):  
M. V. Didenko ◽  
G. S. Pasenov ◽  
G. G. Khubulava
Keyword(s):  
Right Ventricle ◽  
Sinus Node ◽  
Right Atrial ◽  
Permanent Pacing ◽  
Ventricular Stimulation ◽  
The Right ◽  
Stimulation Of

This research includes 74 patients with syndrome of the sinus node asthenia. The application of permanent bilocular pacing was indicated for these patients. An atrial electrode was located in the right atrial auricle in 37 patients and it was in the area of Bakhman’s fascicles in other 37 patients. All the patients had a stimulated atrio-ventricular delay on 250 ms, but sensing delay was shorter on 20 ms. Given data were analyzed after operation in the periods of 6 and 12 months. Cumulative percent of ventricular stimulation was significantly less in the group with electrode in the area of Bakhman’s fascicles (6%) as compared with the group where electrode installed in the right atrial auricle (41%) after 6 months. There were 4% in comparison with 43% after 12 months. The localization of atrial electrode in the area of Bakhman’s fascicles led to reduction of cumulative percent of ventricular stimulation on 35% after 6 months and on 39% after 12 months. Permanent pacing in the area of Bakhman’s fascicles could be an effective mode to decrease the part of amotivational stimulation of the right ventricle.

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