Investigation on cardiac function during anaphylactic shock

本研究的目的是确定过敏反应对麻醉大鼠和离体灌注大鼠心脏左心室功能的影响。用卵清蛋白使大鼠致敏。在麻醉大鼠中，Emax，心脏收缩力指数在抗原注射后15 min不减小反而增大，提示麻醉大鼠在全身过敏反应引起的持续低血压期间心脏收缩力不减小反而增大。在这项研究中，研究人员使用了从Wister大鼠身上切除的离体心脏，这些心脏被卵清蛋白致敏，并以不断流动的血液以交叉循环的方式灌注。通过左室压最大变化率（dP/dt_<max>）和收缩期末压容积关系（ESPVRs）评价心脏收缩力。抗原后冠状动脉血管阻力仅短暂增加4倍于基线。dP/dt_<max>随冠状动脉血流减少而短暂降低。抗原后10分钟测得的ESPVRs与基线相比没有变化。灌注心脏实验结果表明，在离体血液灌注大鼠心脏过敏反应期间，心肌收缩力仅随冠状动脉血流减少而短暂下降。由此可见，抗原暴露后10 min后，心肌收缩力不降低，反而增加。然而，心脏过敏反应本身伴随着短暂的血流依赖性心脏收缩力下降。

The aim of the present study was to determine the effects of anaphylaxis on the left ventricular function in both anesthetized rats and isolated perfused rat hearts. The rats were sensitized with ovalbumin. In anesthetized rats, Emax, an index of cardiac contractility did not decrease but increased at 15 min after antigen injection, suggesting that cardiac contractility did not decrease but increased during sustained hypotension due to systemic anaphylaxis in anesthetized rats. In the study using isolated hearts that were excised from Wister rats sensitized with ovalbumin, and perfused at constant flow with blood in a cross-circulated fashion. Cardiac contractility was evaluated by positive maximum rate of changes in left ventricular pressure (dP/dt_<max>) and end-systolic pressure volume relationships (ESPVRs). After antigen, the coronary vascular resistance increased four times the baseline only transiently after antigen. The dP/dt_<max> decreased transiently along with the decrease in coronary flow. The ESPVRs measured at 10 min after antigen did not change from the baseline. The results from perfused heart experiments suggest that cardiac contractility decreased only transiently along with a decrease in coronary blood flow during cardiac anaphylaxis of isolated blood-perfused rat hearts. In conclusion, cardiac contractility may not decrease, but rather increase later than 10 min after antigen exposure. However, the cardiac anaphylactic reaction itself is accompanied by a transient flow-dependent decrease in cardiac contractility.