Abstract: Cardiac ventricle function can be measured from a multiple-beat pressure volume loop sequence, or estimated from a single beat of pressure volume loop data. In this study, the effectiveness of single-beat estimation is evaluated with functional markers defined by maximum elastance, isovolumic mode developed pressure, ejecting mode pressure volume area, and isovolumic mode pressure volume area. These estimates applied a linear regression model of chamber volume equilibrium as the calculation input. With data collected from 23 published pressure volume diagrams, estimates were assessed for percent differences to multi-beat outcomes. Results by method were: isovolumic pressure volume area (4 ± 4 %), isovolumic peak pressure (8 ± 6 %), ejecting pressure volume area (9 ± 6 %), and maximum elastance (22 ± 17%) p<.0001 one way ANOVA. The isovolumic pressure volume area estimates had the minimum overall error, and appeared to correlate with chamber volume variations through a measured range from 25 mL to 230 mL. This size correlation suggests the method is useful for interpreting normality of natural changes occurring during developmental stages of pediatric patient growth.

Keywords: Pressure Volume Loop, Single-Beat Estimates, Pressure Volume Area, Isovolumic Contracting Mode, Contractility Methods.

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