The heart is one of the principal targets thyroid hormones (TH) action, affecting cardiac contractility, rate, and diastolic function. Oxidative damage pivotal for onset development cardiovascular disease (CVD) failure. Specifically, free radical generation associated to hyper-metabolic state in hyperthyroidism, whereas hypo-metabolic induced by hypothyroidism leads a decrease oxidative stress....

The ,3-adrenergic and calcium channel blocking agents are known to reduce heart rate and alter myocardial contractility. More recent evidence suggests that both agents affect the metabolic consequences of ischemia, independent of their effects on heart rate and contractility. We used a low-flow model of ischemia in swine with heart rate held constant by atrial pacing. Blood was shunted from the...

Changes in left ventricular performance, stroke volume, and peripheral vascular resistance were studied in dogs after combined and separate stimulation of the aortic and carotid chemoreceptors. Selective stimulation of the aortic chemoreceptors produced an immediate increase in myocardial contractility as judged by the force developed by a strain gauge arch sewn into the left ventricular myocar...

Angiotensin-converting enzyme 2 (ACE2) converts the vasopressor angiotensin II (Ang II) into angiotensin (1-7) [Ang(1-7)], a peptide reported to have vasodilatory and cardioprotective properties. Inactivation of the ACE2 gene in mice has been reported by one group to result in an accumulation of Ang II in the heart and an age-related defect in cardiac contractility. A second study confirmed the...

Background. Most positive inotropic agents increase cardiac contractility by increasing the amount of Ca2 cycled with each beat. The additional amount of oxygen that is consumed by the heart to cycle this additional Ca2' is believed to reduce myocardial efficiency. On the other hand, it has been suggested that the agent EMD-53998 increases the Ca2' sensitivity of the contractile proteins withou...

Abstract Acromegaly is associated with cardiovascular disease, the principal cause of increased mortality. Direct cardiac effects GH/IGF-1 are cardiomyocyte growth and contractility, remoddeling. Other important risk factors in acromegaly hypertension, valvular diseases, arrhytmias. Older patients long-term uncontrolled disease may develop congestive heart failure as end-stage acromegalic cardi...

BACKGROUND Myofilament Ca(2+) sensitizers enhance contractility but can adversely alter diastolic function through sensitization to low intracellular Ca(2+) concentration. Concomitant phosphodiesterase III inhibition (PDE3I) may offset diastolic changes but limit the mechanoenergetic benefits. We tested whether selective Ca(2+) sensitization in vivo with the use of EMD-57033 enhances both systo...

In this issue of Circulation Research, Sossalla et al1 show that acute inhibition of Ca /calmodulin-dependent protein kinase (CaMK)II in failing human myocardium causes functional improvement in contractility by restoring a positive force–frequency relationship (FFR) in cardiac trabeculae. The loss of this normal positive FFR (and often an induction of a negative FFR) is a functional hallmark o...

Impaired left ventricular (LV) contractility is a major cause of cardiovascular death, especially congestive heart failure. The identification of susceptibility genes that contribute to impaired LV contractility may uncover mechanisms underlying LV contractile impairment and the development of congestive heart failure. The Hypertension Genetic Epidemiology Network (HyperGEN) collected echocardi...