Effects of pneumatic artificial heart driver on the rate of isovolumic pressure rise.
The aim of the research was to investigate the effects of three parameters of the artificial heart's performance on the (+) dP/dt max. Specifically, the effects of heart rate, left-sided drive pressure, and percent systole (the independent variables) on the (+) dP/dt max (the dependent variable) were examined. The study was conducted using a mock circulation which was connected to an artificial heart. Data were collected using the COMDU software developed for the computer which monitors the artificial heart. Stepwise regression analysis was used to test the three hypotheses. Hypothesis one stated the heart rate would significantly effect the (+) dP/dt max. The hypothesis was not supported. Hypothesis two stated the percent systole would significantly effect the (+) dP/dt max. Hypothesis two was also not supported. Hypothesis three stated the drive pressure would significantly effect the (+) dP/dt max. The hypothesis was supported as drive pressure accounted for 4% of the variance in (+) dP/dt max; however, the results were not clinically significant. Limitations in the study were multicollinearity among the independent variables, small sample size, and the inability of the mock circulation to represent human responses.
Henker
R
R
University Medical Center, Tucson, Arizona.
Murdaugh
C
C
D006339:Heart Rate; D006354:Heart, Artificial; D006801:Humans; D008955:Models, Cardiovascular; D012044:Regression Analysis; D012984:Software; D013599:Systole; D013927:Thrombosis / Q000517:prevention & control