scholarly journals Cardiac sympathetic-parasympathetic balance in rats with experimentally-induced acute chagasic myocarditis

1995 ◽  
Vol 37 (2) ◽  
pp. 155-159 ◽  
Author(s):  
Diego F. Davila ◽  
Carlos F. Gotterberg ◽  
Argenis Torres ◽  
Geza Holzhaker ◽  
Richard Barrios ◽  
...  
Keyword(s):  
Heart Rate ◽  
Beta Blocker ◽  
Sympathetic Activity ◽  
Sinus Tachycardia ◽  
Acute Stage ◽  
Baseline Heart Rate ◽  
Cardiac Sympathetic Activity ◽  
Chronotropic Response ◽  
Cardiac Parasympathetic Activity ◽  
Experimentally Induced

To clarify the mechanism responsible for the transient sinus tachycardia in rats with acute chagasic myocarditis, we have examined the cardiac sympathetic-parasympathetic balance of 29 rats inoculated with 200,000 parasites (Trypanosoma cruzi). Sixteen infected animals and 8 controls were studied between days 18 and 21 after inoculation (acute stage). The remaining 13 infected animals and 9 controls were studied between days 60 and 70 after inoculation (sub-acute stage). Under anesthesia (urethane 1.25 g/kg), all animals received intravenous atenolol (5 mg/kg) and atropine (10 mg/kg). Acute stage: The baseline heart rate of the infected animals was significantly higher than that of the controls (P < 0.0001). The magnitude of the negative chronotropic response to atenolol was 4 times that of the controls (P < 0.00001). This response correlated with the baseline heart rate (r= - 0.72, P < 0.001). The heart rate responses to the beta-blocker and to atropine, of the infected animals studied during the sub-acute stage, were not different from controls. These findings suggest that cardiac sympathetic activity is transiently enhanced and cardiac parasympathetic activity is not impaired, in rats with acute chagasic myocarditis. The transient predominance of cardiac sympathetic activity could explain, in part, the sinus tachycardia observed in the acute stage of experimentally-induced chagasic myocarditis.

scholarly journals Heart rate responses to a muscarinic agonist in rats with experimentally induced acute and subacute chagasic myocarditis

2000 ◽  
Vol 42 (4) ◽  
pp. 219-224 ◽  
Author(s):  
Argenis TORRES ◽  
Diego F. DÁVILA ◽  
Carlos F. GOTTBERG ◽  
Jose H. DONIS ◽  
Gabriela ARATA DE BELLABARBA ◽  
...  
Keyword(s):  
Heart Rate ◽  
Sinus Node ◽  
Regression Line ◽  
Acute Stage ◽  
Baseline Heart Rate ◽  
Muscarinic Agonist ◽  
Parasympathetic Innervation ◽  
Subacute Stage ◽  
Old Rats ◽  
Experimentally Induced

We administered arecoline to rats, with experimentally induced chagasic myocarditis, in order to study the sinus node sensitivity to a muscarinic agonist. Sixteen month old rats were inoculated with 200,000 T. cruzi parasites ("Y" strain). Between days 18 and 21 (acute stage), 8 infected rats and 8 age-matched controls received intravenous arecoline as a bolus injection at the following doses: 5.0, 10.0, 20.0, 40.0, and 80.0 mug/kg. Heart rate was recorded before, during and after each dose of arecoline. The remaining 8 infected animals and 8 controls were subjected to the same experimental procedure during the subacute stage, i.e., days 60 to 70 after inoculation. The baseline heart rate, of the animals studied during the acute stage (349 ± 68 bpm, mean ± SD), was higher than that of the controls (250 ± 50 bpm, p < 0.005). The heart rate changes were expressed as percentage changes over baseline values. A dose-response curve was constructed for each group of animals. Log scales were used to plot the systematically doubled doses of arecoline and the induced-heart rate changes. The slope of the regression line for the acutely infected animals (r = - 0.99, b =1.78) was not different from that for the control animals (r = - 0.97, b = 1.61). The infected animals studied during the subacute stage (r = - 0.99, b = 1.81) were also not different from the age-matched controls (r = - 0.99, b = 1.26, NS). Consequently, our results show no pharmacological evidence of postjunctional hypersensitivity to the muscarinic agonist arecoline. Therefore, these results indirectly suggest that the postganglionic parasympathetic innervation, of the sinus node of rats with autopsy proved chagasic myocarditis, is not irreversibly damaged by Trypanosoma cruzi.

Plasma catecholamines, heart rate, and cardiac sympathetic activity in exercising dogs

1982 ◽  
Vol 14 (4) ◽  
pp. 281-285 ◽  
Author(s):  
FRANÇOIS PÉRONNET ◽  
RÉGINALD NADEAU ◽  
JACQUES de CHAMPLAIN ◽  
CLAUDE CHARTRAND
Keyword(s):  
Heart Rate ◽  
Sympathetic Activity ◽  
Plasma Catecholamines ◽  
Cardiac Sympathetic Activity

scholarly journals Cardiac Sympathetic Activity Assessed by Heart Rate Variability Indicates Myocardial Ischemia on Cold Exposure in Diabetes

2013 ◽  
Vol 6 (3) ◽  
pp. 583-589 ◽  
Author(s):  
Keita Sasaki ◽  
Shonosuke Matsushita ◽  
Fujio Sato ◽  
Chiho Tokunaga ◽  
Kazuyuki Hyodo ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Myocardial Ischemia ◽  
Cold Exposure ◽  
Sympathetic Activity ◽  
Cardiac Sympathetic Activity

scholarly journals Influence of a 100-mile ultramarathon on the heart rate and the heart rate variability

2020 ◽  
Author(s):  
Simone Schrieber ◽  
Christian Paech ◽  
Jan Wüstenfeld ◽  
Ingo Dähnert ◽  
Bernd Wolfarth ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Sympathetic Activity ◽  
Baseline Heart Rate ◽  
Significant Drop ◽  
Rr Intervals ◽  
Suitable Parameter ◽  
The Impact

Abstract INTRODUCTION: The aim of this study was to investigate the impact of an ultra-marathon (UM) with a distance of 100 miles on heart rate (HR) and heart rate variability (HRV). METHODS: Altogether, 28 runners (25 men and 3 women) received a 24-hour long-term ECG one week before the UM (U1), immediately after (U2) and after a week of recovery (U3). The influence of age, body mass index (BMI), HR and HRV on the run time as well as recovery were investigated. RESULTS: A rise in the baseline heart rate accompanied by a significant drop in SDNN values ​​(the standard deviation of all normal RR intervals) was found. Except for the age of the runners, BMI, HF and HRV did not predict the competition time. Full return of HRV to the athlete’s individual baseline did not occur within one week. There were no significant differences between finishers and non-finishers in analyzed parameters. CONCLUSION: The present results show that a 100-mile run leads to an increase in sympathetic activity and thus to an increase in heart rate and a decrease in HRV. In addition, HRV seems to be a suitable parameter to evaluate full recovery after a 100-mile run.

Heart Rate Variability during Chemical Thoracic Sympathectomy

1998 ◽  
Vol 89 (3) ◽  
pp. 666-670. ◽  
Author(s):  
Munetaka Hirose ◽  
Hiroto Imai ◽  
Misako Ohmori ◽  
Yasunori Matsumoto ◽  
Fumimasa Amaya ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Sympathetic Activity ◽  
Scatter Diagram ◽  
Poincaré Plot ◽  
Cardiac Sympathetic Activity ◽  
Concomitant Change ◽  
Thoracic Sympathectomy ◽  
Diagonal Line ◽  
Severe Bradycardia

Background Chemical thoracic sympathectomy (CTS) resulted in profound bradycardia in a patient with severe post-therapeutic neuralgia. To clarify the cause of this bradycardia, the authors evaluated heart rate variability using a Poincaré plot, which is a scatter diagram of the current R-R interval plotted against the R-R interval immediately preceding it, in this patient and in others scheduled for CTS or mandibular block (MB). Methods Twenty-three patients were scheduled for CTS (n = 13, CTS group) and for MB (n = 10, MB group). Heart rate and the SD of the R-R interval variabilities spreading along the x axis (SDRR) and perpendicularly along the diagonal line of the Poincaré plot (SDdeltaRR) were evaluated before, just after, and 1 h after the block. Results Neither group had significant changes in heart rate. The MB group showed no significant change in the SD(RR):SDdeltaRR ratio. In the CTS group, however, the SD(RR):SDdeltaRR ratio decreased significantly from 1.72+/-0.20 to 1.23+/-0.11 just after CTS. The previous patient, who had a high SD(RR):SDdeltaRR ratio of 3.45 before CTS, exhibited severe bradycardia (22 beats/min). Conclusions The SD(RR):SDdeltaRR ratio decreased after CTS without any significant concomitant change in heart rate. The decrease in the SD(RR):SDdeltaRR. ratio indicates a reduction of cardiac sympathetic activity. However, CTS in patients having high SD(RR):SDdeltaRR ratios can result in profound bradycardia.

scholarly journals Influence of a 100-mile Ultramarathon on Heart Rate and Heart Rate Variability

2020 ◽  
Author(s):  
Christian Paech ◽  
Simone Schrieber ◽  
Ingo Dähnert ◽  
Paul Schmidt- Hellinger ◽  
Bernd Wolfarth ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Sympathetic Activity ◽  
Baseline Heart Rate ◽  
Ecg Monitoring ◽  
Significant Drop ◽  
Rr Intervals ◽  
Suitable Parameter ◽  
The Impact

Abstract BACKGROUND: The aim of this study was to investigate the impact of an ultra-marathon (UM) with a distance of 100 miles on heart rate (HR) and heart rate variability (HRV). METHODS: 28 runners (25 males and 3 females) underwent 24-hour Holter ECG monitoring one week before the UM (U1), immediately after (U2) the UM and after a week of recovery (U3). The influence of age, body mass index (BMI), HR and HRV on the run time as well as recovery were investigated. RESULTS: A rise in the baseline heart rate (18.98%) immediately after the run accompanied by a significant drop in the standard deviation of all normal RR intervals (SDNN) (7.12%) one week after. Except for the age of the runners, BMI, HR and HRV showed no influence on the competition time. Full return of HRV to the athletes´ individual baseline did not occur within one week. There were no significant differences between finishers and non-finishers in analysed parameters.CONCLUSION: The present results show that a 100-mile run leads to an increase in sympathetic activity and thus to an increase in heart rate and a decrease in HRV. In addition, HRV might be a suitable parameter to evaluate full recovery after a 100-mile run.

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