Naringin is a flavonoid glycoside found in citrus fruits and grapes with wide range of therapeutic actions. We aimed to study the inotropic effect naringin on rat-isolated atria, dissecting intracellular mechanisms involved this response. Concentration-response curves (0.003-6 mM) were obtained before after pre-incubation selective antagonists. Our results showed that presented biphasic respons...

We studied the hemodynamic effects of surgically induced regional cardiac tamponade in anesthetized dogs. Tamponade restricted to either the right or the left ventricle was compared with tamponade of either ventricle and both atria. Intrapericardial pressures were elevated to approximately 20 mm Hg. With tamponade of the right ventricle alone, aortic pressure rose from 161 +/- 3.8 to 164 +/- 3....

Tissue composition of the atria plays a critical role in the pathology of cardiovascular disease, tissue remodeling, and arrhythmogenic substrates. Optical coherence tomography (OCT) has the ability to capture the tissue composition information of the human atria. In this study, we developed a region-based automated method to classify tissue compositions within human atria samples within OCT im...

The purpose of this study was to determine the importance of inhibition of beta-adrenergic function in thiopentone-induced myocardial depression. Using an isolated, electrically stimulated rat left atria model, contractile dose-response curves to thiopentone (200 microM, 400 microM, 600 microM, 800 microM) were shifted to the right in preparations treated with 10(-3)M dibutyryl cyclic adenosine...

Two monoclonal antibody groups were prepared from adult human atrial and ventricular myosin heavy chains. Using these two groups, we were able to identify two myosin variants in human atria and to classify human atrial fibers into alpha-, mixed, or beta-fibers according to the reactivity of the two monoclonal antibody groups to alpha- and beta-myosin heavy chains of normal young and hypothyroid...

BACKGROUND We treated paroxysmal recurrent atrial fibrillation (AF) with radiofrequency (RF) catheter ablation by creating long linear lesions in the atria. To achieve line continuity, a 3D electroanatomic nonfluoroscopic mapping system was used. METHODS AND RESULTS In 27 patients with recurrent AF, a catheter incorporating a passive magnetic field sensor was navigated in both atria to constr...

This work is dedicated to the simulation of full cycles of the electrical activity of the heart and the corresponding body surface potential. The model is based on a realistic torso and heart anatomy, including ventricles and atria. One of the specificities of our approach is to model the atria as a surface, which is the kind of data typically provided by medical imaging for thin volumes. The b...

1. The affinities of the (R)- and (S)-enantiomers of hexahydro-difenidol (1) and its acetylenic analogues hexbutinol (2), hexbutinol methiodide (3) and p-fluoro-hexbutinol (4) (stereochemical purity greater than 99.8%) for muscarinic receptors in rabbit vas deferens (M1), guinea-pig atria (M2) and guinea-pig ileum (M3) were measured by dose-ratio experiments. 2. The (R)-enantiomers consistently...

The adenosine analogue phenylisopropyladenosine decreased the basal and isoproterenol-stimulated contractile state of isolated rat left atria. The ED50 levels for both responses were similar, suggesting that direct and antiadrenergic effects may be mediated by the same receptor. Phenylisopropyladenosine decreased the cyclic adenosine monophosphate content of isolated atria and inhibited isoprot...

The widely held view that SLN (sarcolipin) would be the natural inhibitor of SERCA1 (sarcoplasmic/endoplasmic-reticulum Ca2+-ATPase 1), and PLB (phospholamban) its counterpart for SERCA2 inhibition is oversimplified and partially wrong. The expression of SLN and PLB mRNA and protein relative to SERCA1 or SERCA2 was assessed in ventricle, atrium, soleus and EDL (extensor digitorum longus) of mou...