The effect of balloon dilatation on post-stenotic myocardial perfusion before and after stimulation of coronary flow reserve: evaluation by the densitometric parameter 'mean rise time'.

Abstract

From densitometric evaluation of digital subtraction cineangiocardiograms the parameter 'Mean Rise Time' (MRT), defined as the time from the onset of local myocardial contrast medium opacification to the point of maximal opacification can be derived; this parameter revealed a close correlation with the results on myocardial perfusion obtained by Thallium-201 scintigraphy. A prolonged 'Mean Rise Time' was indicative of an impairment of myocardial perfusion. We have developed a heart-phase gated real-time digitization procedure and computer-supported method for the densitometric estimation of the MRT to obtain information about the effect of coronary balloon dilatation on myocardial perfusion before and after stimulation of coronary flow reserve by Moxaverin. In 22 patients with single vessel coronary artery disease Moxaverin caused a significant prolongation of the post-stenotic MRT (2.3 +/- 1.2s (mean +/- s.d.) vs. 2.9 +/- 1.1s, p less than 0.05), while after successful dilatation of the obstructive lesion a significant shortening of the MRT was found after stimulation of the coronary flow reserve (2.5 +/- 1.2s vs. 1.9 +/- 0.9s, p less than 0.05). A highly significant decrease in MRT after Moxaverin was measured post-dilatation in comparison to the initial pre-dilatation results (2.9 +/- 1.1s vs. 1.9 +/- 0.9s, p less than 0.005); this shows that the effect of successful balloon dilatation on the post-stenotic myocardial perfusion can be described very well by this parameter. These results demonstrate that information about post-stenotic myocardial perfusion during interventional heart catheterization can be obtained from digital densitometry.