Search results for "atrium"

Struktur-Wirkungs-Beziehungen bei Histaminanaloga, 18. Mitt. Absolute Konfiguration und histaminartige Wirkung der Enantiomere von 5-Amino-4,5,6,7-te…

1979

Es werden die Racemattrennung von 5-Amino-4,5,6,7-tetrahydro-benzimidazol (3), die Bestimmung der absoluten Konfiguration sowie die histaminartige Wirksamkeit der Enantiomere am Ileum (H1) und Atrium (H2) des Meerschweinchens beschrieben. Structure-Activity Relationship of Histamine Analogues, XVIII: Absolute Configuration and Histamine-like Activity of the Enantiomers of 5-Amino-4,5,6,7-tetrahydrobenzimidazole The resolution of 5-amino-4,5,6,7-tetrahydrobenzimidazole (3), the determination of the absolute configuration and the histamine-like activity of the enantiomers on the guinea-pig ileum (H1) and atrium (H2) are reported.

Analysis of in-silico body surface P-wave integral maps show important differences depending on the connections between coronary sinus and left atrium

2016

The electrical connections between the atrial coronary sinus (CS) and the left atrial (LA) myocardium have an effect on the overall atrial activation pattern and the P-wave morphology. In this study, we use our validated multi-scale 3D human atrial-torso model to elucidate which electro-anatomical configuration of connections between CS and LA more accurately reproduces a set of body surface P-wave integral maps (BSPiM) acquired in the clinic. We performed atrial biophysical simulations by pacing in distal and proximal LA sites. The corresponding in-silico BSPiM were then computed and compared with published clinical patterns obtained from patients. Important differences in BSPiM were obser…

Are double potentials markers of a specific zone of the atrioventricular junction in the isolated rabbit heart?

1997

A study is made of the characteristics of the atrial potentials recorded in the Koch triangle and its proximity, their variations on modifying the site of cardiac pacing, and their usefulness as markers of a distinct zone of the AV junction. In 12 isolated and perfused rabbit heart preparations an analysis was made of the endocardial atrial electrograms recorded with a multiple electrode positioned in the AV junction. The electrograms were obtained during spontaneous rhythm and on pacing at the crista terminalis (CT), interatrial septum (IAS), left atrium, and right ventricle. Double potentials were frequently obtained. On pacing at the CT, high-low double potentials (DP [H-L]) were more fr…

Adenosine activates a potassium conductance in guinea-pig atrial heart muscle.

1983

Adenosine shortens the action potential and diminishes the force of contraction in guinea-pig left atria. These effects may be brought about by the activation of a potassium conductance. This assumption is supported by voltage clamp and 42K release experiments.

Silent atrial fibrillation during the acute phase of myocardial infarction

2013

Tetrodotoxin slightly shortens action potential duration in ventricular but not in atrial heart muscle.

1988

Tetrodotoxin (TTX), at concentrations significantly decreasing maximal upstroke velocity (dV/dtmax) of the action potential, exerted variable effects on action potential duration (APD) in different myocardial preparations. APD was virtually unchanged by tetrodotoxin in the guinea pig atrium, but slightly shortened in the guinea pig ventricle at maximally effective concentrations. In the human ventricle, both dV/dtmax and APD were reduced in the same concentration range of TTX. These results suggest that a TTX-sensitive sodium current significantly contributes to the repolarization phase of the action potential in ventricular but not in atrial heart muscle.

Giant left atrium: a condition that is rarely seen today.

2008

Today, giant left atrium is a condition that is rarely observed in clinical practice and diagnosis can be missed. It is prevalent in patients with rheumatic heart disease that has decreased considerably in industrialized countries in the last two decades. However, the immigration flow in the current era can revive its incidence.

AMP-activated protein kinase (AMPK) signaling pathway: A potential mechanism involved in PAFIYAMA syndrome?

2016

Separation of left atrium from right pulmonary artery: a new echocardiographic sign of pericardial effusion.

1981

We report a new echocardiographic sign of pericardial effusion in patients with pericardial effusion examined by the suprasternal approach. In normal individuals the right pulmonary artery is closely connected with the superior wall of the left atrium. A separation of these structures is only to be noticed during atrial contraction. In 12 of 17 patients with a pericardial effusion observed a separation of the left atrium from the right pulmonary artery ranging from 3 to 20 mm throughout the cardial cycle. We suggest that this echo-free zone represents fluid in the transverse pericardial sinus which is located between the two structures. In five patients with a small pericardial effusion (le…

Impact of left atrial diameter on outcome in patients undergoing edge-to-edge mitral valve repair: results from the German TRAnscatheter Mitral valve…

2020

Abstract Background Left atrium (LA) dimension is a marker of disease severity and outcome in primary and secondary mitral regurgitation. In transcatheter mitral valve repair LA enlargement might additionally impact on device handling and technical success through an altered anatomy and atrial annular dilatation. Methods Data from the multicenter German transcatheter mitral valve intervention registry “TRAMI” were used to analyse the association of baseline LA diameter by tertiles and efficacy, safety and long-term clinical outcome in patients undergoing edge-to-edge repair with the MitraClip. Results In 520 of 843 patients prospectively enrolled in TRAMI baseline LA diameter were reported …