Ventricular interaction and external constraint account for decreased stroke work during volume loading in CHF

Moore, Thomas D., Frenneaux, Michael P., Sas, Rozsa, Atherton, J. J., Morris-Thurgood, Jayne A., Smith, Eldon R., Tyberg, John V. and Belenkie, Israel (2001) Ventricular interaction and external constraint account for decreased stroke work during volume loading in CHF. American Journal of Physiology - Heart and Circulatory Physiology, 281 (6). H2385-91. ISSN 0363-6135

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Abstract

The slope of the stroke work (SW)-pulmonary capillary wedge pressure (PCWP) relation may be negative in congestive heart failure (CHF), implying decreased contractility based on the premise that PCWP is simply related to left ventricular (LV) end-diastolic volume. We hypothesized that the negative slope is explained by decreased transmural LV end-diastolic pressure (LVEDP), despite the increased LVEDP, and that contractility remains unchanged. Rapid pacing produced CHF in six dogs. Hemodynamic and dimension changes were then measured under anesthesia during volume manipulation. Volume loading increased pericardial pressure and LVEDP but decreased transmural LVEDP and SW. Right ventricular diameter increased and septum-to-LV free wall diameter decreased. Although the slopes of the SW-LVEDP relations were negative, the SW-transmural LVEDP relations remained positive, indicating unchanged contractility. Similarly, the SW-segment length relations suggested unchanged contractility. Pressure surrounding the LV must be subtracted from LVEDP to calculate transmural LVEDP accurately. When this was done in this model, the apparent decrease in contractility was no longer evident. Despite the increased LVEDP during volume loading, transmural LVEDP and therefore SW decreased and contractility remained unchanged.

Item Type: Article
Uncontrolled Keywords: animals,dogs,female,heart failure,male,myocardial contraction,pericardium,stroke volume,ventricular function, left,ventricular pressure
Faculty \ School: Faculty of Medicine and Health Sciences > Norwich Medical School
Depositing User: Pure Connector
Date Deposited: 09 Mar 2015 07:29
Last Modified: 21 Apr 2020 23:54
URI: https://ueaeprints.uea.ac.uk/id/eprint/52438
DOI: 10.1152/ajpheart.2001.281.6.H2385

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