An assessment of crystalloid solutions for donor heart preservation

The optimal technique for donor heart protection remains controversial. One component of preservation is the transport solution. Although saline solution is most frequently used as a transport medium, other crystalloid solutions may be superior. Accordingly, human right atrial trabeculae contracting isometrically in vitro were used to assess five crystalloid solutions at two different temperatures (12 degrees and 4 degrees C): St. Thomas' Hospital solution, modified Krebs-Henseleit (K+ = 16 mEq/L), Krebs-Henseleit (K+ = 4.5 mEq/L, saline, and Euro-Collins. After a 24-hour preservation period the muscles were restimulated at 34 degrees C and recovery of function was monitored for 30 minutes. Recovery of developed force was not affected by temperature (p = 0.13 by two-way analysis of variance). However, St. Thomas' Hospital solution provided the best recovery of developed force (103.3 +/- 6.2% of control) compared with saline, which had the worst developed force (2.8% +/- 1.3%) (p less than 0.002). Modified Krebs-Henseleit, Krebs-Henseleit, and Euro-Collins demonstrated intermediate performance. Although there were no differences between groups in recovery of resting force, it was greater in all groups with muscles cooled to 4 degrees C (238.7% +/- 17.6% of control) (p less than 0.001). Dry/wet weight ratios did not demonstrate statistically significant differences between groups. We conclude that, of the solutions tested, St. Thomas' Hospital solution provides the best preservation of atrial myocardium. Storage in crystalloid solutions leads to impaired relaxation, which is more apparent in tissue cooled to 4 degrees C and does not appear to be solely due to increased tissue swelling.