Wenckebach arrhythmia produced in cats by vagal stimulation with volleys of electric pulses

1995 ◽  
Vol 120 (1) ◽  
pp. 658-660
Author(s):  
O. E. Osadchii ◽  
V. M. Pokrovskii
Keyword(s):  
Vagal Stimulation ◽  
Electric Pulses ◽  
Wenckebach Arrhythmia

Brief vagal bursts can induce Wenckebach arrhythmia

1989 ◽  
Vol 257 (3) ◽  
pp. H935-H941
Author(s):  
D. W. Wallick ◽  
P. J. Martin
Keyword(s):  
Feedback Control ◽  
Cardiac Cycle ◽  
Vagal Stimulation ◽  
Feedback Control System ◽  
Pentobarbital Sodium ◽  
Control Loops ◽  
Av Conduction ◽  
Retrograde Conduction ◽  
Ventricular Depolarization ◽  
Wenckebach Arrhythmia

We hypothesized that a brief burst of vagal stimulation applied in each cardiac cycle could elicit an atrioventricular (AV) nodal Wenckebach arrhythmia. Twenty-six dogs were anesthetized with pentobarbital sodium (30 mg/kg iv) and were given propranolol (1 mg/kg iv). We varied the timing of a vagal stimulus burst in steps of 25-50 ms relative to the onset of atrial or ventricular depolarization. In four of nine experiments, a Wenckebach arrhythmia occurred despite changing the timing of stimuli. By prolonging the effects of vagal stimulation on AV conduction with physostigmine, the timing of the stimuli no longer influenced the severity of the arrhythmia. We did experiments to open one of the feedback control loops; these results indicated that this arrhythmia has elements of a positive feedback control system. We also studied the effects of vagal stimulation on the arrhythmia during retrograde conduction. We found that the timing of vagal stimulation was critical in eliciting the arrhythmia in only 4 of the 10 dogs.

scholarly journals Using electrodermal activity to validate multilevel pain stimulation in healthy volunteers evoked by thermal grills

2020 ◽  
Vol 319 (3) ◽  
pp. R366-R375
Author(s):  
Hugo F. Posada-Quintero ◽  
Youngsun Kong ◽  
Kimberly Nguyen ◽  
Cara Tran ◽  
Luke Beardslee ◽  
...  
Keyword(s):  
Tissue Injury ◽  
Electrodermal Activity ◽  
Pain Scale ◽  
Potential Harm ◽  
Electric Pulses ◽  
Stimulation Level ◽  
Highly Correlated ◽  
The Brain ◽  
Different Levels ◽  
Assessment Research

We have tested the feasibility of thermal grills, a harmless method to induce pain. The thermal grills consist of interlaced tubes that are set at cool or warm temperatures, creating a painful “illusion” (no tissue injury is caused) in the brain when the cool and warm stimuli are presented collectively. Advancement in objective pain assessment research is limited because the gold standard, the self-reporting pain scale, is highly subjective and only works for alert and cooperative patients. However, the main difficulty for pain studies is the potential harm caused to participants. We have recruited 23 subjects in whom we induced electric pulses and thermal grill (TG) stimulation. The TG effectively induced three different levels of pain, as evidenced by the visual analog scale (VAS) provided by the subjects after each stimulus. Furthermore, objective physiological measurements based on electrodermal activity showed a significant increase in levels as stimulation level increased. We found that VAS was highly correlated with the TG stimulation level. The TG stimulation safely elicited pain levels up to 9 out of 10. The TG stimulation allows for extending studies of pain to ranges of pain in which other stimuli are harmful.

Efferent vagal innervation of canine ventricle

1985 ◽  
Vol 248 (1) ◽  
pp. H89-H97 ◽  
Author(s):  
N. Takahashi ◽  
M. J. Barber ◽  
D. P. Zipes
Keyword(s):  
Coronary Artery ◽  
Vagal Stimulation ◽  
Left Ventricular ◽  
Constant Infusion ◽  
Epicardial Surface ◽  
Before And After ◽  
Vagal Innervation ◽  
The Subject ◽  
Infusion Of Norepinephrine ◽  
The Right

The route efferent vagal fibers travel to reach the left ventricle is not clear and was the subject of this investigation. We measured left ventricular and septal effective refractory period (ERP) changes during vagal stimulation and a constant infusion of norepinephrine, before and after phenol was applied at selected sites of the heart to interrupt efferent vagal fibers that may be traveling in that area. Phenol applied to the atrioventricular (AV) groove between the origin of the right coronary artery anteriorly to the posterior descending branch of the circumflex coronary artery completely eliminated vagal-induced prolongation of ERP in the anterior and posterior left ventricular free wall and reduced, but did not eliminate, ERP prolongation in the septum. A large (3-cm radius) epicardial circle of phenol prevented vagal-induced ERP prolongation within the circle in all dogs, while a small (1-cm radius) epicardial circle of phenol failed to prevent vagal-induced ERP changes within the circle in any dog. An intermediate (2-cm radius) circle eliminated vagal effects on ERP in 13 of 18 dogs. Arcs of phenol, to duplicate the upper portion of the circle, applied sequentially from apex to base eliminated efferent vagal effects only when painted near or at the AV groove. We conclude that the majority of efferent vagal fibers enroute to innervate the anterior and posterior left ventricular epicardium cross the AV groove within 0.25-0.5 mm (depth of phenol destruction) of the epicardial surface.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium bursts induced by nanosecond electric pulses

2003 ◽  
Vol 310 (2) ◽  
pp. 286-295 ◽  
Author(s):  
P.Thomas Vernier ◽  
Yinghua Sun ◽  
Laura Marcu ◽  
Sarah Salemi ◽  
Cheryl M Craft ◽  
...  
Keyword(s):  
Electric Pulses ◽  
Nanosecond Electric Pulses

Electrochemotherapy with cisplatin: potentiation of local cisplatin antitumour effectiveness by application of electric pulses in cancer patients

1998 ◽  
Vol 34 (8) ◽  
pp. 1213-1218 ◽  
Author(s):  
G Serša ◽  
B Štabuc ◽  
M Čemažar ◽  
B Jančar ◽  
D Miklavčič ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Electric Pulses
Sign in / Sign up

Export Citation Format

Share Document