A prolongation of the ventricular effective refractory period in response to cholinergic agonists or vagal stimulation has been demonstrated in a number of in vivo animal models. However, exposure of isolated myocardial tissues obtained from these hearts to as much as10-4 M acetylcholine has been shown to produce essentially no change in action potential duration or effective refractory period....

case relates to the fact that the mouth of the false aneurysm lay in the mitral-aortic intervalvular fibrosa, the junctional tissue between the mitral and aortic valves. The close relationship between this structure and the epicardium was responsible for the peculiar location of the aneurysm in the epicardium between the aorta and the left atrium. Rupture of the false aneurysm led to a fatal he...

Background. Acute ischemia is known to produce more severe electrophysiological disturbances in canine ventricular epicardium than endocardium, although the mechanism for the differential sensitivity is still unresolved. Recent studies have demonstrated the presence of a prominent transient outward current (It.) in ventricular epicardium but not endocardium. The present study was designed to te...

In this paper a left ventricle segmentation approach in shortaxis MRI is proposed. It is based on an active contour method and gradient vector flow field forces. Firstly, algorithm delineates endocardium using active contour method approach assisted by gradient vector flow field forces. After that, the epicardium is outlined by proposed divergence rays method and corrected by Fourier descriptor...

Insight into the role of the epicardium in cardiac development and regeneration has significantly improved over the past ten years. This is mainly due to the increasing availability of new mouse models for the study of the epicardial lineage. Here we focus on the growing understanding of the significance of the epicardium and epicardially-derived cells in the formation of the atrioventricular (...

In mammals, formation of the properly septated 4-chambered heart and coronary vasculature is essential for unidirectional blood flow and survival of the organism. This process involves complex cell-cell interactions, the dysregulation of which can profoundly alter organogenesis, leading to a plethora of structural or functional cardiac defects. No wonder that congenital heart disease (CHD) repr...

The epicardium encapsulates the heart and functions as a source of multipotent progenitor cells and paracrine factors essential for cardiac development and repair. Injury of the adult heart results in reactivation of a developmental gene program in the epicardium, but the transcriptional basis of epicardial gene expression has not been delineated. We established a mouse embryonic heart organ cu...

The epicardium is an epithelial monolayer that plays a central role in heart development and the myocardial response to injury. Recent developments in our understanding of epicardial cell biology have revealed this layer to be a dynamic participant in fundamental processes underlying the development of the embryonic ventricles, the coronary vasculature, and the cardiac valves. Likewise, recent ...

Zebrafish heart regeneration depends on cardiac cell proliferation, epicardium activation and transient reparative tissue deposition. The contribution and the regulation of specific collagen types during the regenerative process, however, remain poorly characterized. Here, we identified that the non-fibrillar type XII collagen, which serves as a matrix-bridging component, is expressed in the ep...