OBJECTIVES The present study was carried out to determine whether inhalation of hydrogen (H(2)) gas protects myocardium against ischemia-reperfusion (I/R) injury in swine. DESIGN In anesthetized open-chest swine, myocardial stunning was produced by 12-minute occlusion of left anterior descending coronary artery (LAD) followed by 90-minute reperfusion in the first study. Group A inhaled 100% o...

BACKGROUND Impaired endothelial-dependent vascular responses after coronary artery occlusion (CAO) and reperfusion (CAR) have been investigated extensively. However, it is not known whether impaired endogenous endothelium-derived relaxing factor production affects postischemic myocardial dysfunction, ie, myocardial stunning. METHODS AND RESULTS Eight dogs were instrumented with an intracorona...

Background Patients with ischemic cardiomyopathy (CMP) often develop regional wall motion abnormalities (WMA) due to myocardial scarring, stunning or hibernation. Abnormal functioning myocardial segments without evidence of fibrosis on late gadolinium-enhancement cardiac magnetic resonance (LGE-CMR) are felt to represent stunned or hibernating myocardium, presumably with significant coronary ar...

See article by Burgdorf et al. [11] (pages 713 –720) in whereas the response to exogenous noradrenaline is unafthis issue. fected [9]. What is the mechanism behind neuronal stunning? It A brief period of ischaemia is known to induce a was initially suggested by Miyazaki and Zipes [8] that high prolonged period of reversible myocardial dysfunction potassium, low pH and adenosine each could inhib...

Brief ischemic episodes confer marked protection against myocardial stunning 1-3 d later (late preconditioning [PC] against stunning). The mechanism of this powerful protective effect is poorly understood. Although protein kinase C (PKC) has been implicated in PC against infarction, it is unknown whether it triggers late PC against stunning. In addition, the entire PKC hypothesis of ischemic PC...

We used an anesthetized swine model of regionally "stunned" myocardium to determine the effect of stunning on coronary autoregulation and blood flow heterogeneity. In 18 domestic swine, stunning was accomplished by reducing blood flow to the left anterior descending coronary artery (LAD) by approximately 75% of baseline for 15 min and restoring it to normal for 1 hour. We quantified coronary au...

this lateralization may result in a change in anisotropy, which was supported by our rat model. In that model a higher degree of lateralization was seen than observed in human chronic AF. However, it is difficult to extrapolate from the rat experiments to the human immunostaining results, for we cannot know how much of the protein positively staining for connexins resembles functional channels....

Contractile dysfunction in stunned myocardium could result from a decrease in the intracellular free [Ca2+] transient during each beat, a decrease in maximal Ca2+-activated force, or a shift in myofilament Ca2+ sensitivity. We measured developed pressure (DP) at several [Ca]0 (0.5-7.5 mM) in isovolumic Langendorff-perfused ferret hearts at 37 degrees C after 15 min of global ischemia (stunned g...