Controversy exists over the rapidity of onset of the inotropic effect of various digitalis glycosides. Shortening of the systolic time intervals (STI) provides a quantitative measure of the inotropic effect of digitalis glycosides in human subjects. Total electromechanical systole corrected for heart rate (QS2I) is the most sensitive of the STI since it combines the shortening effect of digital...

Effects of [Ca211 on isometric tension and unloaded shortening velocity were characterized in single chemically skinned myocytes from frog atrium and in mechanically disrupted myocardium from rat ventricle. The preparations were attached to a force transducer and piezoelectric translator and were viewed with an inverted microscope to allow continuous monitoring of sarcomere length during mechan...

Effects of [Ca2+] on isometric tension and unloaded shortening velocity were characterized in single chemically skinned myocytes from frog atrium and in mechanically disrupted myocardium from rat ventricle. The preparations were attached to a force transducer and piezoelectric translator and were viewed with an inverted microscope to allow continuous monitoring of sarcomere length during mechan...

We examined whether adenosine equally attenuated the stimulatory effects of isoproterenol on arrhythmic activity and twitch shortening of guinea pig isolated ventricular myocytes. Transmembrane voltages and whole cell currents were recorded with patch electrodes, and cell twitch shortening was measured using a video-motion detector. Isoproterenol increased the action potential duration at 50% r...

Fish oil and shortening have been suggested to have opposite effects on cardiovascular disease (CVD). This study investigated the effect of shortening and fish oil on CVD risk factors and aorta histopathology, and the association between risk factors and aorta histopathology. Male Wister rats (n=30) were fed an AIN-93G diet containing 20% fat in the form of fish oil, shortening, or soybean oil ...

background: bone marrow-derived mesenchymal cellscan transdifferentiate into cardiomyocyte cells and improveheart function after transplantation. since biomaterials canimprove the cell retention in the site, cell survival and differentiation,heart tissue engineering is now being explored as anapplied solution to support cell-based therapies and increasetheir efficacy for myocardial diseases. ch...

background abnormalities in the velocity and pattern of myocardial shortening on tissue doppler imaging (tdi) have been proposed to aid in the noninvasive diagnosis of coronary artery disease (cad). objectives we investigated the diagnostic value of post-systolic shortening (pss), a delayed ejection velocity of the myocardium after the closure of the aortic valve, on tdi in the diagnosis of cad...

The relation between shortening heat and sarcomere length was studied using fiber bundles from frog semitendinosus muscles as well as using whole muscles. The initial sarcomere length was varied between 2.0 and 3.66 micron. Shortening heat was estimated as the excess heat produced after a rapid isovelocity release in a 3 sec tetanus at 0 degrees C. The isometric control heat was measured in the...