Maximal, reproducible, and thus, ''standardized'' dilation of epicardi
al coronary arteries can be easily achieved with intracoronary bolus a
dministration of 0.1 mg nitroglycerin without considerable decrease in
blood pressure. The addition of other nitrocompounds or calcium antag
onists cannot increase coronary dilation after nitroglycerin, but may
be hampered by adverse effects.