conclusions these studies will enable physicians to diagnose and follow up many cardiac diseases when this software is interfaced within echocardiographic machines. results myocardial fibers initiate from the posterior basal region of the heart, continue through the left ventricular free wall, reach the septum, loop around the apex, ascend, and end at the superior-anterior edge of the left vent...

Experimental studies demonstrate that short-term regional perfusion-contraction matching, in which the energy demands of regional myocardial contraction are reduced to match the diminished myocardial substrate supply, occurs during states of low coronary blood flow under resting conditions and during exercise-induced ischemia. This phenomenon is rapidly reversible and appears to occur in severa...

INTRODUCTION AND OBJECTIVES Left ventricular filling begins in the ventricular isovolumic relaxation phase. According to the Torrent-Guasp myocardial band theory, this phase results from the contraction of the final portion of the myocardial band: the ascending segment of the apical loop. The objectives were to study the myocardial mechanisms influencing transmitral flow during early diastole a...

A clinical and experimental ultrasound study. Acknowledgement List of papers Abbreviations 1. Introduction 1.1 Regional myocardial contraction – effects of ischaemia 1.2 Detection of regional myocardial dysfunction by standard echocardiography 1.3 The tissue Doppler modalities 2. Aims of the study 2.

The zebrafish (Danio rerio) has been used as a model for studying vertebrate development in the cardiovascular system. In order to monitor heart contraction and cytosolic calcium oscillations, fish were either embedded in methylcellulose or anesthetized with tricaine. Using high-resolution differential interference contrast and calcium imaging microscopy, we here show that dopamine and verapami...

The role of cGMP in myocardial contraction is not established. Recent reports suggest that nitric oxide, released by endothelial cells or within myocytes, modifies myocardial contraction by raising cGMP. We studied the effects of 8-bromo-cGMP (8bcGMP, 50 mumol/L) on contraction (cell shortening) and simultaneous intracellular Ca2+ transients (indo 1 fluorescence ratio) in intact adult rat ventr...

We tested the hypothesis that different subsets of ischemia-induced wall motion disorders are characterized by specific patterns of abnormal regional left ventricular systolic function. Regional contraction was quantitatively assessed from two-dimensional echocardiograms by an automated integrative analysis considering the time course of wall motion during the entire contraction sequence in 20 ...

• The strength of myocardial contraction is influenced directly and strongly by the intervals separating individual beats. The large number of studies on this phenomenon during the 95 years since its original recognition have recently been reviewed. Interval-dependent changes in the strength and time course of contraction result both from alterations in the duration of the active state and from...