mechanism of the cardiovascular system

Transmural variations in gene expression of stretchmodulated proteins in the rat left ventricle

The contribution of refractoriness to arrhythmic substrate in hypokalemic Langendorff-perfused murine hearts

Receding horizon controller for the baroreceptor loop in a model for the cardiovascular system

A recently derived mathematical model of an isolated heart is extended here to a closed-loop cardiovascular system. Taking the end-diastolic volume as state variable, the authors show that the closed-loop cardiovascular system can be described by a one-dimensional nonlinear discrete dynamical

Abstract. This paper is an introduction to the special issue of the Journal of Engineering Mathematic (Volume 47/3-4, 2003) on the mathematical modelling of the cardiovascular system. This issue includes the 2003 James Lighthill Memorial Paper written by Pedley [1] on the mathematical modelling

Our work aims at modelling and simulating the growth processes that allow the cardiovascular system to adapt to the overall body development and to changing physiological (and pathological) conditions. Within the cardiovascular system, we pay particular attention to the heart and the aorta. A

SYNOPSIS. An attempt is made to explain the evolution of different cardiovascular morphologies of crustaceans on the basis of (1) changes in the development of the body plan of different species, (2) the advent in the malacostracans of segmental arteries that provided the circulatory potential

Abstract. Hypomagnesemia is common in hospitalized patients, especially in the elderly with coronary artery disease (CAD) and/or those with chronic heart failure. Hypomagnesemia is associated with an increased incidence of diabetes mellitus, metabolic syndrome, mortality rate from CAD and all causes. Magnesium supple-mentation improves myocardial metabolism, inhibits calcium accumulation and myocardial cell death; it improves vascular tone, peripheral vascular resistance, afterload and cardiac output, reduces cardiac arrhythmias and improves lipid metabolism. Magnesium also reduces vulnerability to oxygen-derived free radicals, improves human endothelial function and inhibits platelet function, including plate-let aggregation and adhesion, which potentially gives magnesium physiologic and natural effects similar to adenosine-diphosphate inhibitors such as clopidogrel. The data regarding its use in patients with acute myocardial infarction (AMI) is conflicting. Although some previous, relatively small randomized clinical trials demonstrated a remarkable reduction in mortality when administered to relatively high risk AMI patients, two recently published large-scale randomized clinical trials (the Fourth International Study of Infarct Survival and Magnesium in Coronaries) failed to show any advantage of intravenous magnesium over placebo. Neverthe-less, there are theoretical potential benefits of magnesium supplementation as a cardioprotective agent in CAD patients, as well as promising results from previous work in animal and humans. These studies are cost effective, easy to handle and are relatively free of adverse effects, which gives magnesium a role in treating CAD patients, especially high-risk groups such as CAD patients with heart failure, the elderly and hospitalized patients with hypomagnesemia. Furthermore, magne-sium therapy is indicated in life-threatening ventricular arrhythmias such as Torsades de Pointes and intractable ventricular tachycardia.

A B S TR A C T What mathematical or physiological principles govern the radii of blood vessels in the cardiovascular system and by what mechanisms are these principles implemented? This question is studied in the contexts of fluid dynamics and physiology of the cardiovascular system, and a possible