COMPARISON OF DIFFERENT TECHNIQUES OF HYPOTHERMIC PIG-HEART PRESERVATION

The aim of this study was to compare several methods of hypothermic he art preservation. Isolated pig hearts were preserved for 24 hours in c old cardioplegic solution (St. Thomas' Hospital modified solution) by continuous perfusion (group I), microperfusion (group II), or simple s torage (group III). The findings were then compared with those from he arts harvested and immediately reperfused (the control group). Group I II hearts showed lower adenosine triphosphate preservation (0.47 +/- 0 .18 mu mol/g) than did group I and II hearts and the control hearts (1 .86 +/- 0.40, 1.98 +/- 0.27, and 1.84 +/- 0.55 mu mol/g, respectively) . Electronic microscopy studies also revealed that the myocardial cell s in the group III hearts appeared to be damaged. After the hearts had undergone preservation, myocardial function was studied for 60 minute s under nonworking conditions using an ex vivo functional testing syst em. For group III, the mean left ventricular developed pressure and ve ntricular compliance (16 +/- 22 and 63 +/- 48 mm Hg, respectively) dif fered significantly from those for group I (83 +/- 26 and 0 +/- 0 mm H g, respectively), group II (83 +/- 33 and 14 +/- 18 mm Hg, respectivel y), and the control group (115 +/- 13 and 0 +/- 0 mm Hg, respectively) . We concluded from our findings that perfusion methods are superior t o cold storage but inadequate to maintain heart viability for the long term during hypothermia. These techniques must be improved before the y can be adopted for clinical use.