Extracellular matrix provides a structural, chemical, and mechanical substrate that is essential in cardiac development, growth, and responses to pathophysiological signals. Transmembrane receptors termed integrins provide a dynamic interaction of environmental cues and intracellular events. Integrins orchestrate multiple functions in the intact organism including organogenesis, regulation of g...

Disturbed sarcoplasmic reticulum (SR) Ca2+ content may underlie the altered force-frequency and postrest contractile behavior in failing human myocardium. We used rapid cooling contractures (RCCs) to assess SR Ca2+ content in ventricular muscle strips isolated from nonfailing and end-stage failing human hearts. With an increase in rest intervals (1 to 240 s; 37 degrees C), nonfailing human myoc...

We evaluated the functional capacity of the intercoronary collateral vasculature in response to graded exercise 2 weeks after acute circumflex coronary artery occlusion. Acute myocardial infarction was produced in 11 chronically instrumented awake dogs by abrupt occlusion of the left circumflex coronary artery. Two weeks later regional myocardial blood flow was measured at rest and during three...

BACKGROUND Previous studies showed that thallium scintigraphy and dobutamine echocardiography were accurate, noninvasive ways of predicting contractile recovery after revascularization in patients with left ventricular (LV) dysfunction. However, the prognostic impact of such methods remains uncertain. METHODS AND RESULTS We prospectively studied 137 consecutive patients with coronary disease ...

Disturbed sarcoplasmic reticulum (SR) Ca content may underlie the altered force-frequency and postrest contractile behavior in failing human myocardium. We used rapid cooling contractures (RCCs) to assess SR Ca content in ventricular muscle strips isolated from nonfailing and end-stage failing human hearts. With an increase in rest intervals (1 to 240 s; 37°C), nonfailing human myocardium (n57)...

BACKGROUND It is unclear if the rat myocardium undergoes the same rapid reductions in protein content that are classically observed in fast-twitch skeletal muscle during endotoxaemia. METHODOLOGY/PRINCIPAL FINDINGS To investigate this further, and to determine if there is any divergence in the response of skeletal muscle and myocardium in the mechanisms that are thought to be largely responsi...

OBJECTIVE Xanthine oxidase (XO) inhibitors enhance myofilament Ca(2+) responsiveness of normal rat myocardium. We examined whether this inotropic action is preserved or magnified in failing rat myocardium and whether the magnitude of this effect correlates with tissue xanthine-oxidoreductase (XOR) activity. METHODS Hearts of 18-20 month-old SHHF (spontaneous hypertensive/heart failure) rats w...

T he differentiation of viable from nonviable myocardium in patients with coronary artery disease and left ventricular dysfunction is an issue of increasing clinical relevance in the current era of myocardial revascularization. It is now well established that impaired left ventricular function does not always represent an irreversible process. However, until recently, determining whether impair...

BACKGROUND Stretch elicits an immediate, followed by a delayed, inotropic response in various animal models and failing human myocardium. This study aimed to characterize functional differences in the stretch response between failing and nonfailing human myocardium. METHODS AND RESULTS Experiments were performed in muscle tissue from 86 failing and 16 nonfailing human hearts. Muscles were str...

We tested the hypothesis that an acute critical limitation in coronary flow reserve could rapidly recapitulate the physiological, molecular, and morphological phenotype of hibernating myocardium. Chronically instrumented swine were subjected to a partial occlusion to produce acute stunning, followed by reperfusion through a critical stenosis. Stenosis severity was adjusted serially so that hype...