Pressure-Controlled Reperfusion Improves Postischemic Recovery of LV-Hypertrophied Rat Hearts

The influence of pressure-con-trolled postischemic reperfusion (Rp) on functional and metabolic parame-ters in hearts of sham-operated rats and hypertrophied hearts of rats with aortic constriction were studied. Hy-pertrophied hearts are considered to be more susceptible to ischemia. The hearts were perfused in the Langendorff-technique for thirty minutes at 35°C with Krebs-Hense-leit bicarbonate buffer at a perfusion pressure (PP) of 75 mmHg and for five minutes at 15°C with St. Thomas ’ Hospital cardioplegic solu-tion at a PP of 60 mmHg. After a per-iod of global ischemia of forty min-utes ’ duration at 15 ° C, reperfusion was started either abruptly (aRp: PP 75 mmHg immediately) or gently (gRp: PP 75 mmHg within thirty minutes); it lasted for forty-five min-utes. Intraventricular peak systolic pressure (ISP) was monitored and en-ergy-rich compounds (ATP, ADP, AMP, CrP, free Cr) were analyzed. at PENNSYLVANIA STATE UNIV on March 5, 2016ang.sagepub.comDownloaded from 575 In normal hearts, metabolic re-covery was not affected by the mode of reperfusion, but functional recov-ery (ISP) averaged 88 % of the preis-chemic control value after gRp as compared with 73 % after aRp. In hypertrophied hearts, gentle reperfusion ameliorated both meta-bolic and functional recovery. At forty-five minute recovery, CrP aver-aged 5.1 μmol/g ww after aRp and 6.6 μmol/g ww after gRp (p < 0.01), and ISP amounted to 73 % of the pre-ischemic control after aRp and to 85 % after gRp