[Long-term preservation of the heart in view of its transplantation. An experimental study]

Actually the maximum preservation time for donor hearts is limited to 4 hours. The aim of this experimental study in dogs was to develop techniques allowing an extension of this period up to 24 hours. In the first part of the study the influence of diastolic arrest on the preservation of high energy phosphates was studied: The following methods of cardioplegic arrest were used: 1. hyperkalemic arrest 2. hyperkalemic arrest plus high magnesium 3. low sodium and calcium-free cardioplegia. In all experiments cardioplegic arrest was followed by cold storage (0.5 degrees C). Single dose K+ plus Mg2+ cardioplegia offered the least protection. The other two types of cardioplegia were better but the ATP content was still below 50% after 24 hrs preservation. Reperfusion after cardiac transplantation induced irreversible injury and function did not recover after transplantation. In the second part of the study continuous hypothermic perfusion with low sodium and calcium-free cardioplegia was studied. With this technique HEP content, myocardial structure and functional recovery were 100% after transplantation.