scholarly journals Modeling Mother Rotor Anchoring in Branching Atrial Tissue

10.5772/26884 ◽  
2012 ◽  
Author(s):  
Gerald Fischer ◽  
Leonhard Wieser ◽  
Florian Hintringer
Keyword(s):  
Atrial Tissue

scholarly journals Isolated atrial tissue preparation for evaluation of cardioactive agents.

2001 ◽  
Vol 117 (3) ◽  
pp. 203-210
Author(s):  
Hikaru TANAKA ◽  
Koki SHIGENOBU
Keyword(s):  
Tissue Preparation ◽  
Atrial Tissue

scholarly journals TASK-1 current is inhibited by phosphorylation during human and canine chronic atrial fibrillation

2015 ◽  
Vol 308 (2) ◽  
pp. H126-H134 ◽  
Author(s):  
Erin Harleton ◽  
Alessandra Besana ◽  
Parag Chandra ◽  
Peter Danilo ◽  
Tove S. Rosen ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Normal Sinus Rhythm ◽  
Human Subjects ◽  
Phosphorylation Site ◽  
Chronic Atrial Fibrillation ◽  
Resting Membrane Potential ◽  
Atrial Remodeling ◽  
Protein Levels ◽  
Atrial Tissue ◽  
Normal Sinus

Atrial fibrillation (AF) is a common arrhythmia with significant morbidities and only partially adequate therapeutic options. AF is associated with atrial remodeling processes, including changes in the expression and function of ion channels and signaling pathways. TWIK protein-related acid-sensitive K+ channel (TASK)-1, a two-pore domain K+ channel, has been shown to contribute to action potential repolarization as well as to the maintenance of resting membrane potential in isolated myocytes, and TASK-1 inhibition has been associated with the induction of perioperative AF. However, the role of TASK-1 in chronic AF is unknown. The present study investigated the function, expression, and phosphorylation of TASK-1 in chronic AF in atrial tissue from chronically paced canines and in human subjects. TASK-1 current was present in atrial myocytes isolated from human and canine hearts in normal sinus rhythm but was absent in myocytes from humans with AF and in canines after the induction of AF by chronic tachypacing. The addition of phosphatase to the patch pipette rescued TASK-1 current from myocytes isolated from AF hearts, indicating that the change in current is phosphorylation dependent. Western blot analysis showed that total TASK-1 protein levels either did not change or increased slightly in AF, despite the absence of current. In studies of perioperative AF, we have shown that phosphorylation of TASK-1 at Thr383 inhibits the channel. However, phosphorylation at this site was unchanged in atrial tissue from humans with AF or in canines with chronic pacing-induced AF. We conclude that phosphorylation-dependent inhibition of TASK-1 is associated with AF, but the phosphorylation site responsible for this inhibition remains to be identified.

Direct and indirect actions of impromidine (a new H2-receptor agonist) on atrial tissue

Life Sciences ◽  
1981 ◽  
Vol 29 (8) ◽  
pp. 817-824 ◽  
Author(s):  
M.J. Hughes
Keyword(s):  
Receptor Agonist ◽  
H2 Receptor ◽  
Atrial Tissue

Modulation of membrane potential by an acetylcholine-activated potassium current in trout atrial myocytes

2007 ◽  
Vol 292 (1) ◽  
pp. R388-R395 ◽  
Author(s):  
Cristina E. Molina ◽  
Hans Gesser ◽  
Anna Llach ◽  
Lluis Tort ◽  
Leif Hove-Madsen
Keyword(s):  
Membrane Potential ◽  
Action Potential ◽  
Ventricular Myocytes ◽  
Reversal Potential ◽  
Membrane Potentials ◽  
Resting Membrane Potential ◽  
Atrial Myocytes ◽  
Atrial Tissue ◽  
Isolated Cardiac Myocytes ◽  
Inwardly Rectifying

Application of the current-clamp technique in rainbow trout atrial myocytes has yielded resting membrane potentials that are incompatible with normal atrial function. To investigate this paradox, we recorded the whole membrane current ( Im) and compared membrane potentials recorded in isolated cardiac myocytes and multicellular preparations. Atrial tissue and ventricular myocytes had stable resting potentials of −87 ± 2 mV and −83.9 ± 0.4 mV, respectively. In contrast, 50 out of 59 atrial myocytes had unstable depolarized membrane potentials that were sensitive to the holding current. We hypothesized that this is at least partly due to a small slope conductance of Im around the resting membrane potential in atrial myocytes. In accordance with this hypothesis, the slope conductance of Im was about sevenfold smaller in atrial than in ventricular myocytes. Interestingly, ACh increased Im at −120 mV from 4.3 pA/pF to 27 pA/pF with an EC50 of 45 nM in atrial myocytes. Moreover, 3 nM ACh increased the slope conductance of Im fourfold, shifted its reversal potential from −78 ± 3 to −84 ± 3 mV, and stabilized the resting membrane potential at −92 ± 4 mV. ACh also shortened the action potential in both atrial myocytes and tissue, and this effect was antagonized by atropine. When applied alone, atropine prolonged the action potential in atrial tissue but had no effect on membrane potential, action potential, or Im in isolated atrial myocytes. This suggests that ACh-mediated activation of an inwardly rectifying K+ current can modulate the membrane potential in the trout atrial myocytes and stabilize the resting membrane potential.

Abstract 12600: Microrna From Atrial Tissue Harvested During Transseptal Puncture as a Predictor for Non-pv Trigger in Patients Undergoing Af Ablation: Preliminary Results From a Pilot Study

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Luigi Di Biase ◽  
Aaron Baker ◽  
Xue Yan ◽  
Jason Lee ◽  
Francesco Santoro ◽  
...  
Keyword(s):  
Therapeutic Option ◽  
Standard Procedure ◽  
Expression Patterns ◽  
Pulmonary Veins ◽  
Challenge Test ◽  
Inverse Correlation ◽  
Patient Specific ◽  
Af Ablation ◽  
Atrial Tissue ◽  
Nonparametric Correlation

Introduction: Catheter ablation of atrial fibrillation (AF) is the most valid therapeutic option to achieve rhythm control. Pulmonary veins (PV) are the most known trigger of AF, although recently we have become more aware of the importance of non-PV triggers. Expression of microRNA (miRNA) has been shown to be regulated in many cardiovascular disease. We sought to study expression patterns of miRNA in patients (pts) with AF undergoing ablation to facilitate their application as both diagnostic and prognostic markers. Methods: As part of the standard procedure for AF ablation a double transseptal sample of myocardial tissue is obtained via a transseptal needle. The small piece of atrial septal tissue can be retrieved from the needle as a result of piercing the atrial septum. MiRNA was hybridized to microarrays to determine relative levels of miRNAs in the samples. For a subset of the miRNAs we validated expression through quantitative real time PCR. All pts underwent PV-antrum and non-PV trigger ablation guided by isoproterenol challenge test. Results: Atrial tissue of 11 pts undergoing AF ablation has been utilized for MiRNA assessment. Mean age was 61.27 ± 10.5 years and 8 (72.7%) pts were male. Six (54.5 %) pts had paroxysmal AF. During the ablation non-PV triggers were detected in 8 (72.7 %) pts. Recurrence of AF occurred in 3(27.3 %) pts. Expression of miR-21, miR-26a and miR-29a was higher in pts with non-PV triggers, while miR-30c had lower expression in pts who had recurrence of atrial tachyarrhythmias. Spearman’s nonparametric correlation coefficient was calculated and miR-21, miR-26a, miR-29a were positively correlated with non-PV triggers (r = 0.58, p=0.06 for all three miRNAs), while miR-30c level had inverse correlation (r = (-) 0.78 %, p=0.005) with recurrence (Figure). Conclusions: Expression of miR-21, miR-26a, miR-29a correlates with the presence of non-PV triggers. This information could be clinically relevant in planning patient specific procedures.

Calcium metabolism in atrial tissue during frequency potentiation and paired stimulation

1970 ◽  
Vol 314 (2) ◽  
pp. 113-123 ◽  
Author(s):  
H. Haacke ◽  
H. Lüllmann ◽  
P. A. van Zwieten
Keyword(s):  
Calcium Metabolism ◽  
Atrial Tissue ◽  
Paired Stimulation ◽  
Frequency Potentiation
Sign in / Sign up

Export Citation Format

Share Document