Does glyceryl trinitrate alter proximal coronary lumen diameter during coronary angiography in patients with chest pain?
Glyceryl trinitrate significantly increases coronary lumen diameter during angiography, suggesting its routine use may mask dynamic coronary narrowing.
Changes in coronary artery tone are often neglected in the angiographic assessment of patients with chest pain. To determine the contributions of dynamic coronary artery diameter changes to the degree of coronary narrowing, 47 consecutive chest pain patients were studied without pre- medication by analysing selective coronary angiograms before and after glyceryl trinitrate. Proximal coronary diameters were measured in superimposed frames with callipers. Lumen diameter increased after glyceryl trinitrate 15 2 per cent in the left main, 18 2 per cent in the left anterior descending, 16 + 2 per cent in the circumflex, and 17 2 per cent in the right coronary arteries (all P < 0.01). One
Feldman et al. (1978) studied this question.