Postconditioning, i.e., brief intermittent episodes of myocardial ischemia-reperfusion performed at the onset of reperfusion, reduces infarct size after prolonged ischemia. Our goal was to determine whether postconditioning is protective against myocardial stunning. Accordingly, conscious chronically instrumented dogs (sonomicrometry, coronary balloon occluder) were subjected to a control seque...

Abstract Background Takotsubo syndrome (TS) and ST-elevation myocardial infarction (STEMI) are both characterized by sudden cessation of contractions (myocardial stunning) as well elevation cardiac troponins B-type natriuretic peptides (BNP). Whereas STEMI results in variable degrees necrosis persistent dysfunction, TS little to any full recovery function. No “head-to-head” comparison the tempo...

BACKGROUND The mechanism through which ischemic preconditioning causes cardioprotection is unknown. The present study investigated the role of stunning in preconditioning. METHODS AND RESULTS We studied three different protocols of preconditioning: two cycles of 2-minute ischemia separated by 5-minute reperfusion (2'PC), one cycle of 5-minute ischemia by 5-minute reperfusion (5'PC1), and two ...

OBJECTIVE To amplify the description of myocardial stunning. DESIGN Control versus 30 min after a 20 min no flow ischaemia. EXPERIMENTAL ANIMALS 15 isolated rabbit hearts perfused with erythrocyte suspension. MAIN OUTCOME MEASURES Left ventricular systolic function in terms of aortic flow, peak systolic pressure (LVPmax), dP/dtmax, and the end systolic pressure-volume relation (ESPVR); ea...

Recent studies suggest that oxygen-derived free radicals contribute to the pathogenesis of postischemic myocardial dysfunction (myocardial "stunning"). This concept, however, is predicated exclusively on results obtained in open-chest preparations, which are subject to the confounding influence of many unphysiological conditions. The lack of supporting evidence in more physiological animal mode...

Although Src protein tyrosine kinases (PTKs) have been shown to be essential in late preconditioning (PC) against myocardial stunning, their role in triggering versus mediating late PC against myocardial infarction remains unclear. Four groups of conscious rabbits were subjected to a 30-min coronary occlusion on day 2, with or without PC ischemia on day 1. Administration of the Src PTK inhibito...

Myocardial stunning is a form of reversible myocardial ischemia/reperfusion injury associated with systolic and diastolic contractile dysfunction. In the isolated rat heart model, myocardial stunning is characterized by specific C-terminal proteolysis of the myofilament protein, troponin I (cTnI) that yields cTnI1-193. To determine the effect of this particular C-terminal truncation of cTnI, wi...

BACKGROUND Administration of Cu/Zn superoxide dismutase (SOD) without catalase fails to alleviate myocardial stunning, but extracellular SOD (Ec-SOD) may be more effective because it binds to heparan sulfate proteoglycans on the cellular glycocalyx. We therefore used in vivo gene transfer to increase systemic levels of Ec-SOD and determined whether this gene therapy protects against myocardial ...