Coronary flow reserve may predict myocardial recovery after myocardial infarction in patients with TIMI grade 3 flow.

Background: The aim of the study was to determine whether the recovery of global and regional left ventricular function after successful percutaneous transluminal angioplasty (PTCA) could be predicted by measuring coronary flow reserve before performing the intervention.

Methods And Results: Thirty-two patients underwent PTCA 6.9 +/- 3.

[N-2-mercaptopropionyl-glycine improves recovery of myocardial stunning after reversible regional ischemia in conscious dogs].

In order to investigate the therapeutic effect of N-2-Mercaptopropionyl-glycine (MPG), a scavenger of hydroxyl radical, on postischemic myocardial dysfunction of 39 conscious unsedated dogs were undergone a 15 min occlusion of left anterior descending coronary artery followed by 48 hours of reperfusion. The treated dogs (n = 17) received an infusion of MPG (100 mg/kg.h) for 60 minutes (starting 15 minutes before occlusion) while the control dogs (n = 22) received normal saline.

Effect of adenosine on myocardial 'stunning' in the dog.

Recent evidence suggests a cardioprotective effect of adenosine in myocardial ischemia and reperfusion. The present study was undertaken to determine (1) whether adenosine attenuates myocardial stunning, (2) if so, whether the beneficial effect of adenosine takes place during ischemia or after reperfusion, and (3) whether adenosine preconditions against myocardial stunning. A total of 93 dogs were used.

Augmentation of endogenous adenosine attenuates myocardial 'stunning' independently of coronary flow or hemodynamic effects.

Background: Mounting evidence suggests a protective effect of exogenous adenosine in myocardial ischemia and reperfusion. We tested the hypothesis that augmentation of endogenous adenosine levels, achieved by inhibiting adenosine catabolism and washout, is beneficial in postischemic myocardial dysfunction ("stunning").

Methods And Results: In phase I of the study, open-chest dogs undergoing a 15-minute coronary artery occlusion and 4 hours of reperfusion received an intracoronary infusion of either saline (controls, n = 23) or 6-(4-nitrobenzyl)-mercapto: purine ribonucleoside (NBMPR, a selective nucleoside transport inhibitor) combined with erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA, a potent adenosine deaminase inhibitor) (EHNA + NBMPR, n = 15) starting 15 minutes before coronary occlusion and ending 15 minutes after the initiation of reflow.

Direct evidence that the hydroxyl radical plays a pathogenetic role in myocardial "stunning" in the conscious dog and demonstration that stunning can be markedly attenuated without subsequent adverse effects.

Recent studies suggest that the hydroxyl radical (.OH) plays a pathogenetic role in postischemic ventricular dysfunction (myocardial "stunning"). This concept, however, is predicated exclusively on results obtained in anesthetized open-chest preparations, which are subject to the confounding influence of many unphysiological conditions and in which both myocardial stunning and free radical generation are greatly exaggerated.