Ischemic preconditioning improves cardiac functional recovery following preservation with University of Wisconsin...

Single or multiple brief periods of regional or global ischemia and reperfusion prior to a prolonged ischemic insult showed cardioprotective effects. Although this phenomenon (ischemic preconditioning [IPC]) has been described in ischemic reperfusion models, the effect of IPC on heart preservation has not been previously reported. We, thus, investigated the effect of IPC on heart preservation. Hearts isolated from male Wistar rats (250-350 g) were mounted on a Langendorff apparatus to estimate baseline function (aortic flow, coronary flow, cardiac output, heart rate, systolic pressure, and rate pressure product). All hearts were divided into 5 groups. In groups 1 and 4, the hearts were subjected to 8 and 12 hr of preservation, respectively. The hearts in group 2 were subjected to a single 2.5-minute cycle of normothermic global ischemic episode (IPC) before 8 hr of preservation. In groups 3 and 5, the hearts were subjected to two 2.5-min IPC cycles and stored for 8 or 12 hr. The hearts were arrested with University of Wisconsin solution and stored at 4 degrees C. Following storage, the hearts were reperfused and measured postpreservative function to assess cardiac functional recovery. Lactate and troponin-T leakage in the coronary perfusate was also measured. In group 3, the treatment of two 2.5-min IPC cycles significantly increased cardiac output, but the treatment of single 2.5-min IPC cycle did not affect the result. In the extended preservation group (group 5), the recovery (%) of both coronary flow and cardiac output were significantly increased compared with group 4. Furthermore, lactate leakage was significantly reduced in groups 2 and 3. These results suggest that IPC improves cardiac functional recovery following simple cold storage and has cardioprotective effects in rat heart preservation.