“…Early investigators [Wiggers and Green, 1936;Zolland Norman, 1952;Kattus el a!., 1959] showed that a variety of drugs including papaverine, sodium nitrite and nitroglycerine had little effect on the collateral circulation. Hedges et al [1961] demonstrated in a small group of dogs that isosorbide dinitrate, when administered after total ligation of the circumflex artery, increased survival from 43% in controls to 100% in the experimentáis. Slejeskog et al [1963], however, showed that isosorbide dinitrate was not effective in the treatment of acute coronary artery ligation in the baboon due to the systemic hypotension caused by the drug.…”