Left ventricular systolic stiffness was measured by rapidly changing ventricular volume (within 7 ms) of isovolumically contracting isolated rabbit hearts. Instantaneous pressure-volume relations were found to be linear with slopes that depended upon the moment during contraction at which the volume change was induced. These slopes were proportional to the total pressure developed in the ventricle just prior to the volume change. The same was found when the time course of pressure was influenced by changing the Ca++ content of the perfusate. An influence, however, also could be detected when end-diastolic volume was changed. At the same pre-release pressure a greater volume caused a decrease of active stiffness. The results indicate the possiblity of an active component in ventricular systolic stiffness.
- Pressure-volume relation
- Quick volume release
- Left ventricle
Schiereck, P., & Boom, H. B. K. (1978). Left ventricular active stiffness: dependency on time and inotropic state. Pflügers Archiv : European journal of physiology, 374(2), 135-143. https://doi.org/10.1007/BF00581294