Effects of sublingual nitroglycerin on coronary lumen diameter and number of visualized septal branches on 64-MDCT angiography.

Objective: This article describes the influence of sublingual nitroglycerin spray on the lumen diameter, number of side branches visualized, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) of the coronary arteries with MDCT angiography.

Subjects And Methods: Forty-two patients were prospectively included in this study: 21 were examined without sublingual nitroglycerin (group A), and 21 were examined after the administration of sublingual nitroglycerin (group B). CT angiography was performed using a 64-MDCT scanner. Two blinded observers quantitatively assessed lumen diameter and volume in the left anterior descending artery (LAD) and the right coronary artery (RCA). The number of septal branches was counted. The SNR and CNR in the LAD and RCA were calculated in both groups. The number of clinical side effects was evaluated.

Results: The lumen diameters and the average volumes were significantly larger in group B than in group A. The number of septal branches visualized in group B was significantly higher than in group A. No statistically significant difference in SNR and CNR between the groups was shown. The number of side effects in the two groups was not significantly different.

Conclusion: Sublingual nitroglycerin spray significantly dilates the coronary arteries and allows more septal branches to be visualized at coronary CT angiography without diminishing image quality or increasing the number of side effects.