scholarly journals Recording Intrinsic Nerve Activity at the Sinoatrial Node in Normal Dogs with High-density Mapping

Author(s):  
Yufan Yang ◽  
Yuan Yuan ◽  
Johnson Wong ◽  
Michael C. Fishbein ◽  
Peng-Sheng Chen ◽  
...  

Background - It is known that autonomic nerve activity controls the sinus rate. However, the coupling between local nerve activity and electrical activation at the sinoatrial node (SAN) remains unclear. We hypothesized that we would be able to record nerve activity at the SAN to investigate if right stellate ganglion (RSG) activation can increase the local intrinsic nerve activity, accelerate sinus rate, and change the earliest activation sites (EASs). Methods - High-density mapping of the epicardial surface of the right atrium (RA) including the SAN was performed in 6 dogs during stimulation of the RSG, and after RSG stellectomy. A radiotransmitter was implanted into 3 additional dogs to record RSG and local nerve activity at the SAN. Results - Heart rate accelerated from 108±4 bpm at baseline to 125±7 bpm after RSG stimulation ( P =0.001), and to 132±7 bpm after apamin injection ( P <0.001). Both electrical RSG stimulation and apamin injection induced local nerve activity at the SAN with the average amplitudes of 3.60±0.72 µV and 3.86±0.56 µV, respectively. RSG stellectomy eliminated the local nerve activity and decreased the heart rate. In ambulatory dogs, local nerve activity at the SAN had a significantly higher average Pearson correlation to heart rate (0.72±0.02, P =0.001) than RSG nerve activity to HR (0.45±0.04 P =0.001). Conclusions - Local intrinsic nerve activity can be recorded at the SAN. Short bursts of these local nerve activities are present before each atrial activation during heart rate acceleration induced by stimulation of the right stellate ganglion.

1997 ◽  
Vol 273 (4) ◽  
pp. H1696-H1698 ◽  
Author(s):  
Cheuk-Wah Wong

With the advent of transthoracic video-assisted endoscopic electrocautery of the second and the third sympathetic ganglia for the treatment of palmar hyperhidrosis, it is possible to approach the stellate ganglia with ease. To see whether stimulation of stellate ganglia in humans is similar to the case in dogs, we stimulated the sympathetic ganglia in 18 palmar hyperhidrosis patients with a coagulation power of 5 W at a frequency of three times every 2 s. We found that left stellate stimulation prolongs the Q-T interval and increases the heart rate, whereas right stellate stimulation affects the Q-T interval and heart rate insignificantly, just like the case in dogs in which the left stellate ganglion predominates the right one in determining the Q-T interval. Left stellate stimulation after destruction of the left second and third ganglia also prolongs the Q-T interval, suggesting that the left stellate ganglion is more important in determining the Q-T interval.


1975 ◽  
Vol 228 (5) ◽  
pp. 1568-1574 ◽  
Author(s):  
MJ Cowan ◽  
AM Scher ◽  
J Hildebrandt

Heart rate response to electrical stimulation of the right stellate ganglion of vagotomized cats was studied before and after the administration of sodium pentobarbital. The increase and decrease of heart rate with the initiation and cessation of sympathetic stimulation could be accurately described by separate exponential time functions. The time constants of rise and decline, the maximum steady-state heart rate, and the time between cessation of stimulation and initial decrease of heart rate (lag) were functions of the frequency and voltage of stimulation. The main effects of sodium pentobarbital were: 1) to prolong the rise of heart rate by 20-30 percent (P smaller than 0.0001),2) to prolong the decay of heart rate by 36-56 percent (P smaller than 0.005), and 3) to decrease the resting heart rate. The effects were observed 10 min after administration of the drug and lasted at least 4 h.


2003 ◽  
Vol 21 (4) ◽  
pp. 133-137 ◽  
Author(s):  
Kenji Imai ◽  
Hiroshi Kitakoji

We investigated the difference in transient heart rate reduction associated with brief acupuncture in 20 healthy subjects at rest in a supine and in a sitting position. After the subjects had been at rest for about 20 minutes, acupuncture needling using the sparrow-pecking method, in which the needle is moved vertically lifting and thrusting, was performed for one minute at the Shousanli point on the right forearm (LI10). The procedure was carried out with the subjects in a supine position and in a sitting position. The position for stimulation of each subject, either supine or sitting, was selected at random, and on different days. The results showed that the average heart rate reduction associated with stimulation in supine subjects was 3.6±0.19 (mean ± standard error {SE}) beats per minute (bpm), while that for sitting subjects was about 7.0±1.07 (mean ± SE) bpm, indicating that stimulation reduces heart rate to a greater degree in subjects who are sitting (p<0.05, Mann-Whitney test). These results would be consistent with a mechanism involving reduced sympathetic drive to the heart, as sympathetic nerve activity has more influence on the heart rate in the sitting than in the supine position.


1962 ◽  
Vol 203 (6) ◽  
pp. 1120-1124 ◽  
Author(s):  
John W. Manning ◽  
Marion deV. Cotten

Electrical stimulation of numerous areas in the midbrain reticular formation and in the posterior hypothalamus of the cat increased blood pressure and caused a variety of electrocardiographic changes, including sinus tachycardia, ventricular premature contractions, bigeminal rhythm, A-V dissociation, and ventricular tachycardia. Most commonly, these arrhythmias developed immediately after cessation of diencephalic stimulation but also developed during the period of stimulation in 5 of the 23 cats studied. The arrhythmias disappeared upon cooling and reappeared upon rewarming the vagus nerves. The arrhythmias also were abolished by methylscopolamine, by bilateral vagotomy, or by extirpation of the stellate ganglia. Electrical stimulation of the distal end of the cut right vagus nerve slowed the sinus rate and electrical stimulation of the right stellate ganglion elevated sinus rate, but neither of these procedures caused arrhythmias. Simultaneous stimulation of both the right vagus nerve and the right stellate ganglion, however, caused arrhythmias similar to those observed after diencephalic stimulation. These data are interpreted to indicate that the cardiac arrhythmias evoked by diencephalic stimulation result from the interplay of both sympathetic and parasympathetic influences on the heart.


EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
C Cataldi ◽  
M Andronache ◽  
R Eschalier ◽  
F Jean ◽  
R Bosle ◽  
...  

Abstract Background The biatrial trans-septal approach (BTSa) ameliorates mitral valve (MV) exposure in difficult cases when routine left atriotomy doesnt"t allow it. Main steps are an oblique incision on the right atrium (RA), reaching medially the right pulmonary veins (PV), a septal incision from the fossa ovalis, extended up to reach the first incision, then on the left atrium (LA). Purpose We aim to study the arrhythmic burden in this post-surgical context, focusing on atrial tachycardia (AT), to investigate the complexity of several possible circuits. Methods All patients (&gt;18yo) with previous MV surgery via BTSa for MV repair or replacement, who underwent ablation of AT from January 2017 to September 2019, were enrolled. Patients ablated for persistent or paroxysmal AF, or with AF during the index procedure were excluded. Patients with associated surgery on other valves or congenital defects, coronary, surgical or percutaneous rhythm interventions weren’t excluded. Electroanatomical mapping was created using 2 different high-density mapping system. Substrate and activation map and radio-frequency (RF) ablation (25-50W, Ablation Index target 400) were realized. Cartographies were analysed to evaluate AT re-entry circuit, critical isthmus (CI) location and characterization, atrial vulnerability. Procedural outcomes (AT termination, sinus rhythm (SR) restoration, anti-arrhythmic drugs (AAD) withdrawal), and peri-procedural complications were also evaluated. Results We enrolled 49 patients (median age 57 ± 15), finding a maximum of 5 AT per procedure (2 ± 1). A total of 112 AT were mapped: the majority (72%) were persistent AT, 8,2% common atrial flutter. Cycle length was 314 ± 74 msec, with proximal-distal activation of coronary sinus (78%). A multiple re-entry circuit was observed in 70% of index AT. We identified 152 critical isthmus (maximum 5 per procedure). Only 27,9% of our patients had a single CI; CTI was the most frequent one (n = 37), envolved in 33% of all AT, while BTS scars altogether were envolved in 65% AT. A complete AT circuit was mapped in the RA, the LA and both atria in respectively 49%, 11,5% and 39%AT. The distribution of CIs is shown in figure 1. Biatrial and left AT leads to superior procedure, RF and fluoroscopy duration (p &lt;0,05). SR was restored in 93,4%of patients, requiring a DC shock in 4 cases. Immediate AAD withdrawal was achieved after 41%procedures. No pericardial, oesophageal, vascular or phrenic complication occurred. 4 pace-maker implantations were realized because of 3 interatrial, 2 AV block and a sinus node dysfunction. Conclusions AT occurring after a BTSa have a high prevalence of multiple re-entry circuits with multiple critical isthmus. Ablation in this context is feasible and safe but often requires a left atrial access. Mapping of both atria should be considered to identify critical isthmus and tailored ablation strategy. Abstract Figure 1. Critical Isthmus Distribution


2017 ◽  
Vol 3 ◽  
pp. 233372141770807 ◽  
Author(s):  
Konosuke Sasaki ◽  
Mayu Haga ◽  
Sarina Bao ◽  
Haruka Sato ◽  
Yoshikatsu Saiki ◽  
...  

Objectives: The aim of this study was to evaluate the effect of the supine, left lateral decubitus, and right lateral decubitus positions on autonomic nervous activity in elderly adults by using spectral analysis of heart rate variability (HRV). Method: Forty-five adults aged 73.6 ± 5.7 years were enrolled. After lying in the supine position, all participants moved to the lateral decubitus positions in a random order and maintained the positions for 10 min, while electrocardiographic data were recorded to measure HRV. Results: The lowest heart rate continued for 10 min when participants were in the left lateral decubitus position compared with the other two positions ( p < .001), while the HRV indexes remained unchanged. The low-frequency HRV to high-frequency HRV ratio (LF/HF) for the right lateral decubitus position was significantly lower than that for the other positions. Discussion: The right lateral decubitus position may attenuate sympathetic nerve activity in elderly adults.


1965 ◽  
Vol 209 (4) ◽  
pp. 751-756 ◽  
Author(s):  
Vincent V. Glaviano ◽  
Mary Ann Klouda

Cardiac responses to electrical stimulation of the right or left stellate ganglion were recorded from 16 open-chest anesthetized dogs in hemorrhagic shock. Shock was induced by bleeding the animals to a mean blood pressure of 40 mm Hg. This level of pressure was maintained for 4 hr, during which time blood pressure, heart rate, force of myocardial contraction, and intraventricular pressures were recorded. Stimulation of the stellate ganglion for 15–40 sec every 30 min after hemorrhage showed a gradual decrease in these parameters to levels below control. The reinfusion of blood and the infusion of exogenous l-norepinephrine did not restore an increase in force of cardiac contraction to stellate stimulation. Myocardial epinephrine and norepinephrine levels in shock were found not to differ from those in 14 normal dog hearts. In contrast to almost complete myocardial refractoriness to stellate stimulation in hemorrhagic shock, stimulation of the vagus nerve elicited bradycardia and eventual cardiac arrest. The decrease observed in force of cardiac contraction to stimulation of the stellate ganglion in hemorrhagic shock may be due to depletion of norepinephrine stores in the heart.


2001 ◽  
Vol 281 (1) ◽  
pp. H132-H138 ◽  
Author(s):  
R. M. Mohan ◽  
S. Golding ◽  
D. J. Paterson

Nitric oxide (NO) decreases norepinephrine (NE) release and the heart rate (HR) response to sympathetic nerve stimulation (SNS). We tested the hypothesis that the enhanced HR response to sympathetic activation following chronic intermittent hypoxia (IH) results from a peripheral modulation of pacemaking by NO. Isolated guinea pig double atrial/right stellate ganglion preparations were studied from animals that had been exposed to IH ( n = 20) and control animals ( n = 22). The HR response to SNS was significantly enhanced in the IH group compared with the controls. However, the increase in HR with cumulative doses (0.1–10 μM) of bath-applied NE was similar in both groups. Western blot analysis showed less neuronal NO synthase in the right atria from the IH group. In IH animals, the NO synthase inhibitor, N ω-nitro-l-arginine (l-NNA; 100 μM) did not alter the increased HR response to SNS, whereas in control animals l-NNA significantly increased the HR response to SNS; an effect that was reversed with excess l-arginine. In conclusion, the enhanced HR response to SNS after IH may be related to a decreased inhibitory action of NO on presynaptic NE release.


1983 ◽  
Vol 244 (2) ◽  
pp. R235-R243
Author(s):  
J. M. Goldberg ◽  
M. H. Johnson ◽  
K. D. Whitelaw

The effects of supramaximal stimulation of the right and left cervical vagi on heart rate, pacemaker localization, and atrioventricular (AV) conduction were investigated in 15 anesthetized open-chest chickens before and after atropine sulfate. Epicardial bipolar electrograms were recorded from selected atrial sites and right ventricle. A back lead electrocardiogram was also recorded. The effect of stimulation on atrioventricular conduction was evaluated during pacing from one of the right atrial recording sites. Supramaximal stimulation of either cervical vagus produced bradycardia but not cardiac arrest. Heart rate was reduced from an average spontaneous rate of 282 +/- 13 (SE)/min to 161 +/- 13/min with stimulation of the right and left cervical vagus. Pacemaker shifts occurred in over 50% of the vagal stimulations. The most frequent shift occurred to the lower AV node or ventricles. Pacemaker shifts to the AV junctional region producing almost simultaneous activation of the atria and ventricles were not observed. Vagal stimulation during atrial pacing produced minimal prolongation in AV conduction time [right vagus, 13 +/- 3 (SE) ms; left vagus, 8 +/- 2 ms]. Second and third degree heart blocks were not observed during pacing. Vagal stimulation after atropine indicates that the cervical vagi do not contain sympathetic fibers going to pacemaker or AV conduction tissues.


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