Left ventricular performance in endotoxin shock in XXXX .

@entity296 @entity235 @entity31820 @entity3485 @entity204
Endotoxin shock, with maximal velocity of contraction (Vmax) as our index of contractility, showed no @entity296 in an earlier 4-h study (Guntheroth, @entity31820 . Soc. Exp. Biol. Med. 157: 610--614, 1978). Because of reports of late deterioration, we studied six @entity235 until spontaneous @entity204 (9--18 h). Heart rate nearly doubled and left ventricular filling pressure and aortic mean pressure fell, but Vmax did not change significantly. Because of concern that the marked increase in heart rate may have contributed to an artifactual maintenance of Vmax (due to its frequency dependence, inherent in dp/dt), we studied a final group of five @entity235 with three additional indicators of contractility. End-systolic pressure-diameter ratio (Emax), ejection fraction (sonar-determined from the minor axis of the left ventricle), and frequency-normalized average rate of generation of power density (FARPD) all fell early and remained low until @entity204 . We conclude that myocardial contractility is significantly reduced in endotoxin shock, early and sustained. Its presence is masked somewhat in the untreated subject by the reduced work load, secondary to @entity3485 .
