| Background and objectiveHeart transplantation is an effective method for treatment of end-stage heart disease,the quality of donor heart preservation is a key to the success of hearttransplantation.The current clinical donor heart preservation is given priority to withcold ischemia preservation, but to save time is limited, difficult to break through the4-6h.In order to extend the heart save time, in recent years, a variety of donor heartpreservation methods, including mechanical myocardial perfusion of pig heart forheart save the model become one of research hotspots.This research continues toperfusion in vitro cardiac system, determination of different perfusion flow her leftventricular systolic pressure, diastolic blood pressure, myocardial oxygenconsumption, heart rate to evaluate the in vitro cardiac function, to explore new typeof donor heart preservation and heart function evaluation method.Materials and Methods:The same blood type24healthy Swedish pigs (of either sex, weight55-65(60±5)kg) as experimental subjects, including12as a blood donor, and the other12for theheart donor. Respectively, from the blood donor and the donor heart each randomlyselected six, as the experimental group (group R), the remaining12pigs was the control group (group C). Followed by the preparation of isolated heart model,feeding the pig model, and connect seq prepared in advance cardiopulmonary bypassmachine, only perfusion blood flow in0.76L/min or more pigs and found that in thepre-experiment was able to maintain a pig heart in vitro normal blood pressure andheart rate. Group R to make the indicators began to stabilize after4h test, arterialblood gas extraction before the test and coronary sinus venous blood gas, givendifferent perfusion flow (respectively,0.76L,1L,2L,3L,4L per minute), each to beisolated heart indicators (isolated heart blood pressure, heart rate does not rise) afterstable recording every minute left anterior descending coronary artery blood flow (F),arterial blood drawn five times, five times the coronary venous blood gas analysisperformed by the blood gas analysis machine and accurate record of each hemoglobin(Hb), arterial oxygen saturation (AsO2), venous oxygen saturation (VsO2), from theheart of the heart rate, systolic blood pressure, mean pressure, left ventricularsystolic pressure, etc., and then to0.76L/min flow perfusion1h after repeating theabove steps, a total of three times, three times the results were averaged. Group C isto make the indicators began to stabilize after1h test, repeat the above steps. Afterthe end of each test piece cut out of a ventricular cardiac muscle wet weight wasweighed, after which it was placed in the baking oven at80℃48h, and thenweighing the dry heart, myocardial water content calculated. All isolated heartanterior descending coronary artery distal to take1/3of vessels and vessel diametermeasurements, underwent organ bath experiments (organ bath).ResultThe high flow compared with low flow, myocardial oxygen consumption (F=23.5，P <0.05)the heart rate （F=331，P <0.05）and systolic blood pressure（F=77.7，P <0.05）, average pressure（F=10.1，P <0.05） and left ventricular systolic bloodpressure（F=89.3，，P <0.05）, difference was statistically significant， Myocardialoxygen uptake rate (F=0.46，P>0.05), there was no statistically significant difference.Two myocardial water content (F=0.006, P>0.05), there was no statisticallysignificant difference, the inner diameter of the coronary (F=1.02, P>0.05), t therewas no statistically significant difference, the largest artery diastolic values (F=3.33,P>0.05), there was no statistically significant difference, pEC50(F=0.385, P>0.05),there was no statistically significant difference.Conclusion By monitoring the myocardial oxygen consumption, heart rate, blood pressure andother hemodynamic parameters, accurate evaluation of cardiac function, blood flow tothe foundation (0.76L/min)3h infusion after cardiac preservation, myocardial watercontent was not found significant differences in coronary artery no significantdifferences in internal diameter, differences were not statistically different betweenthe maximum diastolic coronary endothelium-dependent. The high flow than lowflow when the heart rate, systolic blood pressure, diastolic blood pressure differences,such as between left ventricular systolic pressure was statistically significant,indicating that the low-flow perfusion preservation under continuous warm bloodfrom the heart of myocardial edema did not occur, coronary artery endothelial cellsdid not significantly impaired heart function is good, get better preserved. |
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