EVALUATION OF HEMODYNAMIC-EFFECTS OF NITROGLYCERIN ON THE UTILITY OF TRANSESOPHAGEAL ECHOCARDIOGRAPHY FOR DIAGNOSIS OF CORONARY-ARTERY STENOSIS

We evaluated left anterior descending coronary artery stenosis by tran sesophageal echocardiography using the acute hemodynamic effects produ ced by administration of nitroglycerin (NTG) spray in 11 patients with stenosis and 8 subjects without stenosis (normal group). Before admin istration of NTG, there were no differences in systolic and diastolic blood pressures, heart rate, the diameter of the left main trunk, syst olic 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 redu ced 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 lac k of significant differences in NTG-induced changes in blood pressure and heart rate between the two groups, NTG significantly increased pea k SFV and DFV in both groups, The average NTG-induced change in SFV wa s similar in both groups, but the increase in DFV was significantly gr eater in the stenosis group compared with the normal group, Consequent ly, the DFV:SFV decreased significantly after NTG administration in th e normal group but not in the stenosis group, The change in DFV:SFV wa s significantly different between the two groups, Our results suggest that NTG spray is potentially useful for enhancing the diagnostic util ity of transesophageal echocardiography for stenosis of the left desce nding coronary artery.