facilitates the preservation of a heart for example during transport prior to a heart transplant operation the preferred active chemical agent of the preferred cardioplegic solution is 2 3 butanedione monoxime bdm or homologues thereof homologues as that term is used herein refers to compounds e g structurally related compounds which exhibit similar cardioplegic properties when administered to an organism a preferred concentration range for bdm in the cardioplegic solutions is from 10 40 mm the bdm solution can be prepared in any physiologically compatible buffer one such buffer is krebs ringer which contains physiologically acceptable levels of na k cl so 4 2 ca 2 glucose a preferred cadioplegic composition is given in the exemplification as an optional ingredient insulin e g 10 iu per liter can be included as shown in the exemplification the addition of insulin when combined with an increase in the glucose concentration to 11 2 mm increased yielded stable performance in the assay to a level of 80 100 the cardioplegic solutions are administered by contacting the solution with the myocardium for example a cardioplegic solution equilibrated with a 95 o 2 co 2 gas mixture can be introduced by pressure perfusing the coronary circulation cardioplegia can also be induced by immersing the heart or a region of the heart in a cardioplegic solution this immersion perfusion also provides a convenient method for transferring a heart from a donor to a recipient prior to a transplant operation the cardioplegia or other muscle stoppage can be reversed by removing the solution preferably at 30 u00b0 c bdm induced cardioplegia blocks muscle contraction in a relaxation state without causing sustained contraction which would mechanically damage muscle cells and seriously deplete the cellular energy stores atp and pcr shortening the permissible duration of cardiac arrest muscle tissue.