Myocardial contrast echocardiography for assessment of papaverine vasodilator response in patients with angiographically normal coronary arteries and in patients after orthotopic heart transplantation.

Myocardial contrast echocardiography has the potential for assessing changes in regional myocardial perfusion. We used this method to compare papaverine vasodilator response in 10 patients after orthotopic heart transplantation without acute rejection of left ventricular hypertrophy (HTX) and in 15 patients with angiographically normal coronary arteries (control group). Injections of 2 ml of sonicated iopromid (9 paired injections in HTX and 24 paired injections in the control group) were performed before and after intracoronary application of papaverine (8 or 10 mg) into the left or right coronary artery. From regional time-intensity curves, alpha (variable of curve width), area under the curve (area), peak contrast intensity (Imax) and contrast decay half-time (T1/2) were derived by from a gamma variate function. T1/2 increased from 4.2 +/- 1.2 to 7.2 +/- 4.0 s (p < 0.01) after papaverine in HTX compared to a change from 4.8 +/- 1.0 to 6.0 +/- 1.7 s (p < 0.001) in normal subjects. Alpha decreased in HTX from 0.44 +/- 0.15 to 0.27 +/- 0.10 s-1 (p < 0.01) after intracoronary papaverine injection. In the control group alpha was 0.37 +/- 0.08 s-1 at rest compared to 0.30 +/- 0.08 s-1 at hyperemic conditions (p < 0.002). Area increased in HTX from 444 +/- 261 to 910 +/- 732 U.s (p < 0.01) and in normal subjects from 352 +/- 171 to 585 +/- 262 U.s (p < 0.001). Hyperemic to baseline flow ratios for area varied from 0.9 to 3.8 (mean 2.17 +/- 1.11) in HTX compared to 1.76 +/- 0.52 (1.03 to 2.71) in normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)