[Measurement of shortening characteristics in human heart using biplane coronary cineangiograms]

Biplane coronary cineangiograms were analyzed to measure spatial distance (segment length) of the coronary artery in man. The coordinates of the points of the artery (x, y, z) were measured and the segment length between Pn and Pm was calculated as follows: segment length = square root of (xn - xm)2 + (yn - ym)2 + (zn - zm)2. This calculation was performed frame by frame covering one cardiac cycle and the shortening and relaxation characteristics of the segment length were determined. The extent of the systolic shortening of the segment was the greatest at the free wall at the base along the long axis (13.9 +/- 2.0%) and the least along the atrioventricular groove (0.8 +/- 3.7%). The shortening started 77.3 msec earlier at the apex than at the base. In conclusion, the present method is useful to analyze shortening characteristics of the segment length in man.