Coronary dilators and cardioplegia.

The distribution in the myocardium of cardioplegic solution is demonstrated in dog hearts with the aid of indocyanine green. When papaverine or nitroglycerin are added to the solution, a much improved diffusion is observed. Papaverine appears to be a better coronary dilator. We deduce from this observation that myocardial protection during ischemic arrest for open-heart surgery is enhanced considerably when coronary dilation is assured.