We have reported the linear relation of myocardial oxygen consumption per beat (VO(2)) and systolic pressure-volume area (PVA) in the left ventricle of the cross-circulated rat heart. The VO(2) intercept (PVA-independent VO(2)) is primarily composed of VO(2) for Ca(2+) handling in excitation-contraction coupling and basal metabolism. Recently, we proposed a new index for oxygen cost of contract...

STUDIES on myocardial contractility and coronary flow during vagal stimulation have yielded inconsistent results. This may be due to the fact that in most studies heart rate was not maintained constant and both ventricular function and coronary blood flow are influenced by changes in heart rate. When heart rate was maintained constant, no change in myocardial contractility was found." In the pr...

Protein kinase (PK)C , PKC , and PKC comprise the conventional PKC isoform subfamily, which is thought to regulate cardiac disease responsiveness. Indeed, mice lacking the gene for PKC show enhanced cardiac contractility and reduced susceptibility to heart failure. Recent data also suggest that inhibition of conventional PKC isoforms with Ro-32-0432 or Ro-31-8220 enhances heart function and ant...

The effects of exogenous and endogenous. NO on myocardial functions such as contraction, relaxation and heart rate have recently gained considerable scientific interest. .NO stimulates myocardial soluble guanylate cyclase to produce cGMP, which activates two major target proteins. A small increase in cGMP levels predominantly inhibits phosphodiesterase III, while high cGMP levels activate cGMP-...

OBJECTIVES We sought to compare left ventricular (LV) systolic stiffness and contractility in normal subjects, hypertensive patients without heart failure, and patients with heart failure and preserved ejection fraction (HFpEF) and to determine whether LV systolic stiffness or myocardial contractility is associated with the rate of mortality in patients with HFpEF. BACKGROUND Arterial load is...

The P2X4 receptor is a newly identified receptor expressed in the heart cell. Its function was elucidated with cardiac transgenic (TG) expression of the receptor by using the myocardium-specific a-myosin heavy chain promoter. The presence of the transgene was determined by polymerase chain reaction by using primers specific to the receptor and the vector linker region, by Southern blotting of t...

The cardiovascular effects of glucagon were determined in cats and dogs anaesthetized with halothane. Glucagon increased heart rate and myocardial contractility but did not produce ventricular arrhythmias. Adrenaline and isoprenaline, which also increased heart rate and myocardial contractility, did produce ventricular arrhythmias. The cardiac stimulant effects of glucagon were not prevented by...

[PDF] [Full Text] [Abstract] , April 2, 2008; 29 (8): 1019-1028. Eur. Heart J. Frigerio, M. Parides, D. Burkhoff and G. Hindricks Curnis, D. Bocker, A. Remppis, J. Kautzner, M. Stuhlinger, C. Leclerq, M. Taborsky, M. M. M. Borggrefe, T. Lawo, C. Butter, H. Schmidinger, M. Lunati, B. Pieske, A. R. Misier, A. electrical impulses for symptomatic heart failure Randomized, double blind study of no...

BACKGROUND The cardiovascular effects of halogenated anesthetic agents in children with normal hearts have been studied, but data in children with cardiac disease are limited. This study compared the effects of halothane, isoflurane, sevoflurane, and fentanyl-midazolam on systemic and pulmonary hemodynamics and myocardial contractility in patients with congenital heart disease. METHODS Fifty-...

the cardiac action of phenoxybenzamine (dibenzyline) was studiedusing the maximum rate of pressure rise in the left ventricle as a measure of myocardial contractility. cardiac function was assessed by increasing the pressure load on the heart and measuring contractility as reflected by dp/dt. dibenzyline was found to change the cardiac response to pressure load. the rate of pressure increase in...