Evaluation of hemodynamic effects of nitroglycerin on the utility of transesophageal echocardiography for diagnosis of coronary artery stenosis

Abstract We evaluated left anterior descending coronary artery stenosis by transesophageal echocardiography using the acute hemodynamic effects produced by administration of nitroglycerin (NTG) spray in 11 patients with stenosis and 8 subjects without stenosis (normal group). Before administration of NTG, there were no differences in systolic and diastolic blood pressure, heart rate, the diameter of the left main trunk, systolic flow velocity (SFV), diastolic flow velocity (DFV), or the ratio of diastolic flow velocity to systolic flow velocity (DFV:SFV) between the normal and stenosis groups. NTG administration significantly reduced systolic and diastolic blood pressures and significantly increased heart rate and the diameter of the left main trunk in each group. The increase in diameter of the left main trunk was significantly greater in the normal group compared with the stenosis group, despite the lack of significant differences in NTG-induced changes in blood pressure and heart rate between the two groups. NTG significantly increased peak SFV and DFV in both groups. The average NTG-induced change in SFV was similar in both groups, but the increase in DFV was significantly greater in the stenosis group compared with the normal group. Consequently, the DFV:SFV decreased significantly after NTG administration in the normal group but not in the stenosis group. The change in DFV:SFV was significantly different between the two groups. Our results suggest that NTG spray is potentially useful for enhancing the diagnostic utility of transesophageal echocardiography for stenosis of the left descending coronary artery.