Negative inotropic effect of XXXX is attenuated in underperfused feline heart with an acute ischemic region.

@entity1169 @entity1563 @entity741 @entity299 @entity432 @entity850 @entity551
beta-Adrenergic blockade alleviates @entity741 , probably largely through @entity299 . We hypothesized that the negative inotropic effect of beta-blockade, which is believed to be potentially dangerous, is attenuated in underperfused hearts with an acute @entity1563 . We studied the effect of intravenous @entity1169 (1 mg/kg i.v.) in feline hearts with acute circumflex coronary artery (LCX) occlusion by cross-oriented segments in normally perfused and mildly underperfused left ventricular (LV) anterior wall. A control group (n = 10) was compared with a @entity850 group (n = 9) in which the mean coronary perfusion pressure was reduced (91 +/- 4 g vs. 136 +/- 5 mm Hg, p < 0.01). End-systolic pressure-length (ESP-ESL) relations during dynamic afterload increase and preload reduction were calculated to evaluate regional inotropy. HR and @entity551 ( @entity551 ) decreased in both groups after beta-blockade (p < 0.05). Subendocardial and mid-myocardial blood flow measured by radiolabeled microspheres decreased in the control group (p < 0.05) but was unchanged in the @entity850 group. Systolic shortening of circumferential segments also decreased in the control group (p < 0.05) but was unchanged in the @entity850 group. ESP-ESL relations of circumferential segments shifted markedly rightward in the control group, whereas a modest rightward shift was noted in the @entity850 group. This study in feline heart with @entity432 showed an attenuated negative inotropic effect of beta-blockade in underperfused LV anterior wall.
