BACKGROUND Systemic levels of arginine vasopressin (AVP) are increased in congestive heart failure, resulting in vasoconstriction and reduced cardiac contractility via V(1) vasopressin receptors. V(2) vasopressin receptors (V2Rs), which promote activation of adenylyl cyclase, are physiologically expressed only in the kidney and are absent in the myocardium. Heterologous expression of V2Rs in th...

AIMS Genetic mouse models have yielded conflicting conclusions about the role of PI3Kα in heart physiology: specifically, the question of whether PI3Kα has a direct role in regulating myocardial contractility. This has led to concerns that PI3K inhibitors currently in clinical trials for cancer may potentiate cardiotoxicity. Here we seek to clarify the role of PI3Kα in normal heart physiology a...

Left ventricular ejection time (LVET) is defined as the interval from aortic valve opening to closure, and phase of systole during which left ventricle ejects blood into aorta. LVET has been used for several decades assess function contractility. However, there a recent interest in measure therapeutic action novel drugs patients with heart failure reduced fraction (HFrEF), since shortened these...

A cardiac contractility modulation device is a new treatment used in patients with heart failure. CCM therapy associated an increase physical activity tolerance, improved quality of life, reduced hospitalizations due to failure, and reverse remodeling the left ventricle systolic In this case, clinical benefit patient chronic atrial fibrillation postinfarction aneurysm was reported. Development ...

Kadambi, Vivek J., Nancy Ball, Evangelia G. Kranias, Richard A. Walsh, and Brian D. Hoit. Modulation of force-frequency relation by phospholamban in genetically engineered mice. Am. J. Physiol. 276 (Heart Circ. Physiol. 45): H2245–H2250, 1999.—Phospholamban levels regulate cardiac sarcoplasmic reticulum Ca21 pump activity and myocardial contractility. To determine whether and to what extent pho...

We have assessed resting myocardial contractility and its baroreflex control in normotensive and hypertensive conscious rabbits. Hypertension was induced by bilateral cellophane wrapping of the kidneys with experiments performed 6 weeks later during the established phase of hypertension. The peak rate of change of left ventricular pressure (peak LV dP/dt) was used as the index of myocardial con...

Coronary artery fistula (CAF) is an anomaly making a coronary communicate with heart cavity or great vessel, thus bypassing the myocardial capillary bed. CAF frequently diagnosed as incidental finding. Herein, we present case of 4-year-old boy. He was referred for pediatric cardiology assessment due to continuous murmur at middle sternal border. Echocardiogram showed dilated left and abnormal d...

Right ventricular (RV) failure due to chronic pressure overload is a main determinant of outcome in congenital heart disease. Medical management is challenging because not only contractility but also the interventricular relationship is important for increasing cardiac output. This study evaluated the effect of milrinone alone and in combination with epinephrine or dopamine on hemodynamics, ven...

This Controversies in Research article discusses the hypothesis that protein kinase A (PKA)-mediated phosphorylation of the Ryanodine Receptor (RyR) at a single serine (RyRS2808) is essential for normal sympathetic regulation of cardiac myocyte contractility and is responsible for the disturbed Ca(2+) regulation that underlies depressed contractility in heart failure. Studies supporting this hy...

RATIONALE Mitogen-activated protein kinases (MAPKs) are activated in the heart by disease-inducing and stress-inducing stimuli, where they participate in hypertrophy, remodeling, contractility, and heart failure. A family of dual-specificity phosphatases (DUSPs) directly inactivates each of the MAPK terminal effectors, potentially serving a cardioprotective role. OBJECTIVE To determine the ro...