Figure 4.
Plot of nitroglycerin- and adenosine-associated changes in coronary cross-sectional area versus baseline measurements. An upward shift in vessel cross-sectional area with nitroglycerin (long dashed line with gray circles) from the line of identity (dark line) favors enhanced visualization. The downward shift in the regression line for intravenously adenosine (dotted line and open circles) suggests poorer visualization.