Abstract
Mechanical work of left ventricle during cardiac assist was studied by acute in vivo experiments on mongrel dogs with normal hearts under five driving modes. Newly developed 8-channel ultrasonic displacement meter was utilized to determine left ventricular diameter and regional muscular length. The left ventricular mechanical work was calculated from the displacement data and left ventricular pressure. The whole left ventricular work as well as the regional muscular work under any pumpingg modes were reduced significantly by the left ventricular assist, maximally under asynchronous modes and followed by under 2:1 synchronous mode.
