EFFECTS OF RESERPINE AND ADRENALINE ON ATRIAL FIBRILLATION

1964 ◽  
Vol 42 (4) ◽  
pp. 385-389 ◽  
Author(s):  
M. Lavallée ◽  
G. Tremblay ◽  
A. Beaulnes
Keyword(s):  
Atrial Fibrillation ◽  
Electrical Stimulation ◽  
Action Potential ◽  
Firing Rate ◽  
Low Potassium ◽  
Before And After ◽  
Antiarrhythmic Property ◽  
Rabbit Atria

The resistance of isolated rabbit atria to arrhythmic factors such as low potassium medium, acetylcholine, and electrical stimulation was determined before and after contact with reserpine and following administration of large doses of adrenaline. Animals pretreated with reserpine were found more sensitive to arrhythmic factors than untreated controls. Moreover, adrenaline was shown, in most cases, to abolish the induced arrhythmias or to lower the frequency of the atrial firing rate. As already suggested by Burn, this antiarrhythmic property of adrenaline at the atrial level is considered to be the result of an antagonism with acetylcholine, presumably through a lengthening of the duration of the action potential.

Ventricular Rate During Atrial Fibrillation Before and After Slow-Pathway Ablation

Circulation ◽  
1996 ◽  
Vol 94 (5) ◽  
pp. 1023-1026 ◽  
Author(s):  
S. Adam Strickberger ◽  
Raul Weiss ◽  
Emile G. Daoud ◽  
Rajiva Goyal ◽  
Frank Bogun ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Ventricular Rate ◽  
Slow Pathway ◽  
Slow Pathway Ablation ◽  
Before And After

scholarly journals P496Remodeling of atrial action potential duration and atrial chamber deformation: a potential link in the development of atrial fibrillation?

2018 ◽  
Vol 114 (suppl_1) ◽  
pp. S120-S120
Author(s):  
L Sartiani ◽  
L Sartiani ◽  
M Cameli ◽  
L Dini ◽  
S Modillo ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Action Potential ◽  
Action Potential Duration ◽  
Potential Link

scholarly journals Insights into the combination of neuromuscular electrical stimulation and motor imagery in a training-based approach

2021 ◽  
Author(s):  
Amandine Bouguetoch ◽  
Alain Martin ◽  
Sidney Grosprêtre
Keyword(s):  
Electrical Stimulation ◽  
Motor Imagery ◽  
Neural Plasticity ◽  
Neuromuscular Electrical Stimulation ◽  
Voluntary Contraction ◽  
Muscle Architecture ◽  
Fascicle Length ◽  
Before And After ◽  
V Wave ◽  
And Control

Abstract Introduction Training stimuli that partially activate the neuromuscular system, such as motor imagery (MI) or neuromuscular electrical stimulation (NMES), have been previously shown as efficient tools to induce strength gains. Here the efficacy of MI, NMES or NMES + MI trainings has been compared. Methods Thirty-seven participants were enrolled in a training program of ten sessions in 2 weeks targeting plantar flexor muscles, distributed in four groups: MI, NMES, NMES + MI and control. Each group underwent forty contractions in each session, NMES + MI group doing 20 contractions of each modality. Before and after, the neuromuscular function was tested through the recording of maximal voluntary contraction (MVC), but also electrophysiological and mechanical responses associated with electrical nerve stimulation. Muscle architecture was assessed by ultrasonography. Results MVC increased by 11.3 ± 3.5% in NMES group, by 13.8 ± 5.6% in MI, while unchanged for NMES + MI and control. During MVC, a significant increase in V-wave without associated changes in superimposed H-reflex has been observed for NMES and MI, suggesting that neural adaptations occurred at supraspinal level. Rest spinal excitability was increased in the MI group while decreased in the NMES group. No change in muscle architecture (pennation angle, fascicle length) has been found in any group but muscular peak twitch and soleus maximal M-wave increased in the NMES group only. Conclusion Finally, MI and NMES seem to be efficient stimuli to improve strength, although both exhibited different and specific neural plasticity. On its side, NMES + MI combination did not provide the expected gains, suggesting that their effects are not simply cumulative, or even are competitive.

scholarly journals Exercise and the Risk of Dementia in Patients with Newly Diagnosed Atrial Fibrillation: A Nationwide Population-Based Study

2021 ◽  
Vol 10 (14) ◽  
pp. 3126
Author(s):  
Jaehyun Lim ◽  
So-Ryoung Lee ◽  
Eue-Keun Choi ◽  
Kyung-Do Han ◽  
Jin-Hyung Jung ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Risk Reduction ◽  
Lower Risk ◽  
Population Based ◽  
Newly Diagnosed ◽  
Incident Dementia ◽  
Before And After ◽  
Korean National Health Insurance ◽  
New Diagnosis ◽  
New Onset

Background: It is unclear whether exercise would reduce dementia in patients with a new diagnosis of atrial fibrillation (AF). Therefore, we aimed to evaluate the association between the change in physical activity (PA) before and after new-onset AF and the risk of incident dementia. Methods: Using the Korean National Health Insurance Service database, we enrolled a total of 126,555 patients with newly diagnosed AF between 2010 and 2016, who underwent health examinations within two years before and after their diagnosis of AF. The patients were divided into four groups: persistent non-exercisers, exercise starters, exercise quitters, and exercise maintainers. Results: Based on a total of 396,503 person-years of follow-up, 5943 patients were diagnosed with dementia. Compared to persistent non-exercisers, exercise starters (adjusted hazard ratio (aHR) 0.87; 95% confidence interval (CI) 0.81–0.94), and exercise maintainers (aHR 0.66; 95% CI 0.61–0.72) showed a lower risk of incident dementia; however, the risk was similar in exercise quitters (aHR 0.98; 95% CI 0.92–1.05) (p-trend < 0.001). There was a J-shaped relationship between the dose of exercise and the risk of dementia, with the risk reduction maximized at 5–6 times per week of moderate-to-vigorous PA among exercise starters. Conclusion: Patients who initiated or continued regular exercise after diagnosis of AF were associated with a lower risk of dementia than persistent non-exercisers, with no risk reduction associated with exercise cessation. Our findings may provide evidence for the benefit of exercise prescription to patients with new-onset AF to prevent incident dementia regardless of their current exercise status.

scholarly journals Are Three Weeks of Oral Anticoagulation Sufficient for Safe Cardioversion in Atrial Fibrillation?

Medicina ◽  
2021 ◽  
Vol 57 (6) ◽  
pp. 554
Author(s):  
Stefan Naydenov ◽  
Nikolay Runev ◽  
Emil Manov
Keyword(s):  
Atrial Fibrillation ◽  
Sinus Rhythm ◽  
Oral Anticoagulation ◽  
Left Atrial ◽  
Left Atrial Volume ◽  
Open Label ◽  
Before And After ◽  
Individualized Approach ◽  
Baseline Factors ◽  
And Function

Background and Objectives: Patients with atrial fibrillation (AF), lasting >48 h, considered for cardioversion, are recommended ≥3 weeks of oral anticoagulation before sinus rhythm restoration because of high risk of development of left atrial thrombosis (LAT) and stroke. However, the optimal duration of anticoagulation in the presence of overt LAT is unknown. Materials and Methods: An open-label study aimed to investigate the prevalence of spontaneous echo contrast (SEC) and LAT before and after 3 weeks of direct oral anticoagulant (DOAC) treatment. We included 51 consecutive patients (50.9% males), mean age 69.3 ± 7.4 years with paroxysmal/unknown duration of AF, considered for cardioversion, who agreed to have transesophageal echocardiography at enrollment and 3 weeks later. Results: At baseline SEC was present in 26 (50.9%) and LAT in 10 (19.6%) of 51 patients. After 3 weeks on DOAC, SEC persisted in 12 (25.0%) and LAT in 7 (14.5%) of 48 patients, p < 0.05 vs. baseline. Factors, associated most strongly with persistence of SEC/LAT, were left atrial appendage (LAA) emptying velocity <20 cm/s (OR = 2.82), LAA lobes >2 (OR = 1.84), and indexed left atrial volume ≥34 mL/m2 (OR = 1.37). Conclusions: In our study the incidence of SEC/LAT, particularly in AF with unknown duration, was not as low as we expected. The prevalence of SEC/LAT seemed to be dependent on factors not routinely evaluated in AF patients planned for cardioversion (indexed LA volume, LAA morphology and number of lobules, LAA emptying velocity, etc.). Our data suggested an individualized approach for DOAC duration in AF patients before an attempt for restoration of sinus rhythm is made, taking into consideration the LAA morphology and function.

Evaluation of the Renin-Angiotensin-Aldosterone system before and after catheter ablation of atrial fibrillation

Heart Rhythm ◽  
2005 ◽  
Vol 2 (5) ◽  
pp. S240
Author(s):  
Frédéric Sacher ◽  
Agnes Georges ◽  
Prashantan Sanders ◽  
Jean-Benoit Corcuff ◽  
Philippe Schraub ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Catheter Ablation ◽  
Renin Angiotensin Aldosterone System ◽  
Renin Angiotensin ◽  
Before And After
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