Myocardial blood flow is spatially heterogeneous, reflecting nonuniform oxygen supply. Also, myocardial oxidative metabolism is spatially heterogeneous. The effects of acute ischemia and reperfusion on the relationship between local myocardial blood flow (LMF) and oxidative metabolism are still unknown. LMF was measured in isolated, blood-perfused rabbit hearts using colored microspheres and ox...

“Preconditioning with ischemia” (PC) is the phenomenon whereby one or more episodes of brief ischemia paradoxically renders the myocardium resistant to a later, more sustained ischemic insult (1–3). The cardioprotection afforded by brief, transient ischemia is biphasic; a “first window” of protection is manifest within the initial 5 min to approximately 3 h of the PC stimulus, the hallmark of w...

Proteins are no longer just ingredients for biologists: Proteinaceous materials are gradually stepping into the spotlight as highly functional next generation materials, despite the fact that “material science” has previously mainly been explored by chemists. In the September 16th issue of Journal of American Chemical Society, Tezcan and co-workers report an interesting methodology to prepare a...

Reperfusion after brief, reversible myocardial ischemia is associated with prolonged depression of contractile function (myocardial "stunning"); however, the effect on coronary vascular function has not been defined. Thus, open-chest dogs (n = 14) underwent a 15-minute left anterior descending coronary artery (LAD) occlusion followed by reflow. Four hours after reperfusion, regional myocardial ...

Although previous studies suggested that the protection of late preconditioning (PC) against myocardial stunning is mediated by nitric oxide (NO), direct evidence that exogenous administration of NO attenuates myocardial stunning is lacking. Furthermore, although exogenous NO administration was shown to elicit a late PC phase, it is unknown whether NO donors also induce an early PC phase. There...

We have recently demonstrated the benefits of glucagon-like peptide-1 (GLP-1) in enhancing regional and global myocardial function after reperfusion in the clinical setting of acute myocardial infarction. We hypothesized that GLP-1 facilitates recovery from myocardial stunning after an ischemic event. To investigate this, we administered GLP-1 (1.5 pmol/kg/min) to six dogs undergoing 10-min occ...

Catecholamine-induced cardiomyopathy due to chronic excess of endogenous catecholamines has been recognized for decades as a clinical phenomenon. In contrast, reports of myocardial dysfunction due to acute iatrogenic overdose are rare. A 35-year-old woman whose cervix uteri was inadvertently injected with 8 mg of epinephrine developed myocardial stunning that was characterized by severe hemodyn...

The warm up phenomenon, first described more that 50 years ago in patients with effort angina, refers to the improved performance exhibited by more than half of all patients with coronary artery disease following their first exercise test. There are several potential causes of the warm up phenomenon including: (1) an improvement in oxygen supply, which, in turn, may be caused by stenosis dilati...