Oral Nitroglycerin Research Articles

Quantitative Angiography: The Measurement of Coronary Vasomobility in the Intact Animal and Man

Coronary arteriography was performed on 49 dogs and 85 patients before and repeatedly after administration of placebo, nitroglycerin and isosorbide dinitrate (ISDN), utilizing various doses and routes of administration. The cine coronary arteriograms were then carefully measured, frame by frame, during the arterial phase of the injections. The measurements were averaged with the aid of a computer and the changes of coronary artery diameter, when present, were expressed as percentage variations above or below the baseline. This study demonstrated that: (1) the diameter of the coronary arteries can be accurately measured in intact, living subjects; (2) both canine and human coronary arteries exhibit a slow, but appreciable reduction of their diameter, probably associated with inactivity and sedatives or both; (3) both injectable, and oral nitroglycerin and injectable sublingual and oral ISDN are powerful dilators of the large coronary arteries (including the collateral branches when present), occasionally inducing vasodilatation of as much as 163 percent above the pretreated coronary artery diameter.