Journal of cardiac surgery
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Measures of left ventricular (LV) contractility must be linear, load-independent, free of hysteresis, and sensitive to changes in inotropic state. These properties of measures of LV contractility have been assessed previously in animals, but never in man. Using a micromanometer and volume conductance catheter technology, we measured LV pressure and volume in 67 patients scheduled for CABG surgery. ⋯ Neither the slope nor the intercept of any of the three measures of contractility changed significantly with loading conditions. Heart rate demonstrated no physiologically significant baroreceptor-mediated changes during the perturbations. Comparing measures of LV function--ejection fraction (EF%), LV end-diastolic pressure (LVEDP), dP/dtMax-EDV, PLRSW, ESPVR, -dP/dtMax-EDV, and end-diastolic pressure-volume relationship (EDPVR)--in patients with a preoperative medical history of congestive heart failure (CHF), myocardial infarction (MI), and hypertension (HTN) demonstrated lower EF percent (62.4 +/- 16.7 vs 42.8 +/- 5.0 [p < 0.0002]) and lower ESPVR (2.27 +/- 1.98 vs 1.30 +/- 0.83 [p < 0.03]) in patients with a history of CHF.(ABSTRACT TRUNCATED AT 250 WORDS)
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Review Clinical Trial Controlled Clinical Trial
The management of temperature during cardiopulmonary bypass: effect on neuropsychological outcome.
Laboratory studies demonstrate that mild degrees of brain cooling (2 degrees C to 5 degrees C) confer substantial protection from ischemic brain injury, and that mild elevation of brain temperature can be markedly deleterious. During hypothermic cardiopulmonary bypass (CPB) patients are made hypothermic and then rewarmed at a time when they are exposed to neurological insults. Our studies show that during rewarming, peak brain temperatures near 39 degrees C often are achieved inadvertently. ⋯ We found patient acceptability and compliance were good. Sensitivity also seemed adequate in that 30% of patients were identified as having deteriorated at 1 week postoperatively compared to preoperatively, a result similar to that reported by others. Clinical trials of the efficacy of mild hypothermia in modulating brain injury in humans are needed before techniques of CPB can be designed to optimize neuroprotection.