[Evaluation of regional wall motion of the left ventricle before and after nitroglycerin administration in patients with ischemic heart disease: comparison between two-dimensional echocardiograms and coronary angiograms].

Effects of nitroglycerin (NTG) on segmental wall motion and pump function of the left ventricle (LV) were studied in 19 patients with ischemic heart disease (IHD) and 10 normal controls by two-dimensional echocardiography (2DE) and coronary arteriography (CAG). Short-axis cross-sectional images of the LV at the mitral valve, papillary muscles and the apex were recorded and subdivided into quadrants at each level. The center of gravity of the end-diastolic LV cavity and the axis intersecting this point and the right side of the posterior end of the interventricular septum were used as the reference point and line. The areas of whole sections and of each quadrant at end-diastole (Ad) and end-systole (As) were measured by the computer. Regional contractility and pump function of the LV were evaluated by (Ad-As)/Ad and (Ad-As) of quadrants and sections. The results were as follows: Blood pressure (BP), Ad and (Ad-As) of sections significantly decreased after NTG administration. (Ad-As)/Ad of the sections with normal wall motion showed no significant change after NTG. (Ad-As)/Ad of the quadrants with hypokinetic segmental wall motion showed a tendency to increase after NTG in contrast with the normal quadrants which showed no significant change. CAG findings and hemodynamic parameters in patients who showed a significant increase in (Ad-As)/Ad of all sections after NTG (Gr. I) were compared with those in patients who showed a decrease in (Ad-As)/Ad of all sections (Gr. II). There was no significant correlation between CAG findings in Gr. I and Gr. II. The only difference between these two groups before NTG was that mean Ad of sections in Gr. I was significantly greater than that of Gr. II. After NTG, Gr. I showed a significant decrease of BP, but Gr. II did not show any significant change. (Ad-As) of sections in Gr. I increased or showed no change after NTG, but those in Gr. II decreased. In conclusion, NTG can reverse wall motion asynergy, especially in hypokinetic segments, and produce favorable changes in pump function in patients with increased Ad before NTG. The mechanism of NTG to improve wall motion and pump function is considered to be afterload and preload reduction.