[The significance of improved angiocardiography systems in the quantitative assessment of proximal coronary stenosis. Comparison of angiographic and hemodynamic measurements in vivo].

The use of high resolution X-ray techniques for biplane coronary angiography can improve the quantitative assessment of coronary stenoses when perpendicular projections in both views can be achieved. Angiograms thus obtained of coronary stenoses before (n = 17) and after (n = 14) coronary dilatation were evaluated for mean and minimal stenosis diameters of two planes and for percent narrowing of stenoses (caliper measurements). Comparisons with transstenotic pressure gradients showed significant or highly significant correlations for all dimensional parameters. It is concluded that quantitative angiographic analysis of coronary stenoses yields highly reliable results of hemodynamic relevance. In addition, a mean diameter of less than 1.6 mm could be identified as indicating hemodynamically significant stenosis.