Nuclear medical determination of the left ventricular normalized velocity of contraction.

The normalized velocity of contraction (vn) and its maximal value (vnmax) are related to the normalized flow acceleration within the ventricle, to the subendocardial fiber shortening rate, strain rate, and stress. This paper presents the method of the nuclear medical determination of vn and analyzes a typical volume-velocity-time curve. In 60 patients with different stages of coronary artery disease, global vnmax showed good correlation with the minimal ventricular transit time (y = 6.18-1.36 x, P less than 0.001) and global ejection fraction (y = -(2.5 + 356/(x - 104], P less than 0.001). The segmental vnmax showed a highly significant correlation with the regional ejection fraction (y = -(2.5 + 371/(x - 104], P less than 0.001). The mathematical relationships of vn with the mechanical properties of the ventricular wall are described in the appendix.