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Hawthorne, E. W.

Publications and source records attributed to Hawthorne, E. W..

4 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Estimation of left ventricular mass in conscious dogs

A method for the assessment of the development or the regression of left ventricular hypertrophy (LVH) in a conscious instrumented animal is described. First, the single-slice short-axis area-length method for estimating the left-ventricular mass (LVM) and volume (LVV) was validated in 24 formaldehyde-fixed canine hearts, and a regression equation was developed that could be used in the intact animal to correct the sonomicrometrically estimated LVM. The LVM-assessment method, which uses the combined techniques of echocardiography and sonomicrometry (in conjunction with the regression equation), was shown to provide reliable and reproducible day-to-day estimates of LVM and LVV, and to be sensitive enough to detect serial changes during the development of LVH.

Coleman, Bernell↗
NASA NTRS1977

Cardiovascular studies using the chimpanzee (Pan troglodytes)

Despite the phylogenetic similarities between chimpanzees and man, there exists a paucity of reliable data on normal cardiovascular function and the physiological responses of the system to standard interventions. Totally implanted biotelemetry systems or hardwire analog techniques were used to examine the maximum number of cardiovascular variables which could be simultaneously monitored without significantly altering the system's performance. This was performed in order to acquire base-line data not previously obtained in this species, to determine cardiovascular response to specific forcing functions such as ventricular pacing, drug infusions, and lower body negative pressure. A cardiovascular function profile protocol was developed in order to adjust independently the three major factors which modify ventricular performance, namely, left ventricular performance, left ventricular preload, afterload, and contractility. Cardiac pacing at three levels above the ambient rate was used to adjust end diastolic volume (preload). Three concentrations of angiotensin were infused continuously to evaluate afterload in a stepwide fashion. A continuous infusion of dobutamine was administered to raise the manifest contractile state of the heart.

Hinds, J. E.↗
NASA NTRS1972

Prolonged weightlessness (300 plus days) and cardiac performance in primates. 1: Neuro-humoral mechanisms in the control of cardiac and vascular performance in conscious animals

Research during the period 1 Oct. 1971 to 1 Oct. 1972 is reported. Studies discussed include: development of techniques for instrumentation of dogs and other animals, effects of temporary application of lower body negative pressure, and effect of infusing selected drugs on ventricular performance.

Hawthorne, E. W.↗