Swanson D K, Myerowitz P D, Watson K M
J Surg Res. 1985 Nov;39(5):378-89. doi: 10.1016/0022-4804(85)90091-5.
Preservation of the myocardium in vitro is more effective than preservation in vitro when preservation conditions are apparently the same. The washout of cardioplegia from the myocardium by noncoronary blood flow has been implicated as a probable cause of the poorer myocardial preservation seen in vivo. Isolated dog hearts were used to study the effects of cardioplegia washout by low flow perfusion (0.05 ml/min/g LV weight) during a 2-hr preservation period. Six experimental groups of five hearts each underwent 2 hr of myocardial preservation at temperatures of 20 degrees C (three groups) or 30 degrees C (three groups). The three groups for each temperature consisted of retrograde coronary sinus perfusion (to simulate cardioplegia washout by collateral flow) with blood cardioplegia (BC), normal blood (NB), or no perfusion at all (No CSP). The quality of preservation in each group was assessed by measuring recovery of left ventricular function, tissue water and electrolyte content, and myocardial high-energy phosphate and adenylate content prior to, during, and following preservation. In hearts maintained at 20 degrees C, cardioplegia washout did not significantly affect left ventricular function or myocardial levels of H2O, Na, K, ATP, or total adenylates. When myocardial temperature was allowed to increase to 30 degrees C, preservation was better with low flow perfusion during the preservation period. Hearts warmed to 30 degrees C with no cardioplegia washout experienced a 50% loss of tissue ATP levels and recovered less than 30% of normal left ventricular function during a 150-min reperfusion period. In contrast, hearts slowly perfused during the preservation period maintained nearly normal levels of ATP and returned to normal function by 150 min of reperfusion. Although myocardial warming by noncoronary perfusion has a detrimental effect on myocardial preservation, the slow washout of cardioplegia per se has no apparent detrimental effect on preservation.
在保存条件明显相同的情况下，体外心肌保存比体内保存更有效。非冠状动脉血流将心脏停搏液从心肌中冲洗出去，这被认为是体内心肌保存较差的一个可能原因。使用离体犬心来研究在2小时保存期内低流量灌注（0.05毫升/分钟/克左心室重量）对心脏停搏液冲洗的影响。六个实验组，每组五颗心脏，分别在20℃（三组）或30℃（三组）温度下进行2小时的心肌保存。每个温度下的三组分别为逆行冠状窦灌注（模拟侧支血流对心脏停搏液的冲洗），分别使用血液心脏停搏液（BC）、正常血液（NB）或根本不灌注（无冠状窦灌注，No CSP）。通过在保存前、保存期间和保存后测量左心室功能恢复情况、组织水和电解质含量以及心肌高能磷酸盐和腺苷酸含量，来评估每组的保存质量。在保持在20℃的心脏中，心脏停搏液的冲洗对左心室功能或心肌中的水、钠、钾、三磷酸腺苷（ATP）或总腺苷酸水平没有显著影响。当心肌温度升至30℃时，在保存期间进行低流量灌注时保存效果更好。在没有心脏停搏液冲洗的情况下升温至30℃的心脏，在150分钟的再灌注期内组织ATP水平损失50%，左心室功能恢复不到正常水平的30%。相比之下，在保存期间缓慢灌注的心脏在再灌注150分钟时维持了几乎正常的ATP水平，并恢复到正常功能。虽然非冠状动脉灌注引起的心肌升温对心肌保存有不利影响，但心脏停搏液本身的缓慢冲洗对保存没有明显的不利影响。
