Journal of Applied Physiology, Vol 40, Issue 2 196-205, Copyright © 1976 by American Physiological Society
Comparative evaluation of pressure and time factors in estimating left ventricular performance
F. L. Abel
Left ventricular and ascending aortic pressures were measured in open chest
mongrel dogs under pentobarbital anesthesia. The data were digitized,
averaged, and subgrouped by mean systolic aortic pressures (MSAP),
end-diastolic pressure (EDP), and heart rate (HR). Seven raw and 32 derived
variable from the pressure, as a function of time, wave forms were analyzed
in each subgroup in the control state and following the infusion of
catecholamines. A plot of control variability versus sensitivity to
norepinephrine indicates that time to peak ventricular pressure (PVP time)
is a more sensitive indicator of changes in the inotropic state than such
other commonly used variables as max dP/dt, integrated isometric tension,
and (max dP/dt)/developed pressure. PVP time also showed less variability
with HR, EDP, and MSAP. Regression lines were also fit to the data using a
second-order model. This permitted evaluation of experimentally varying
either HR, EDP, or MSAP while maintaining the other two constant. PVP time
was again one of the better variables in terms of sensitivity to HR, EDP,
or MSAP. Vmax, fractional rate of change of power, preejection period, and
systolic time were also analyzed and compared with PVP time using averaged
data.
