Using gated radionuclide ventriculography and invasive cardiac monitoring, the effects of propofol and methohexital on left ventricular volumes and function were investigated in 22 unpremedicated patients (ASA physical status III, 50-78 yr) with chronic coronary artery disease (NYHA class II-III). Anesthesia was induced with either propofol or methohexital (2 mg/kg), followed by a maintenance infusion of 100 micrograms.kg-1.min-1. Vecuronium (0.05 mg/kg) was administered and ventilation (FIO2, 1.0) was manually controlled (FECO2, 0.04-0.05). Data acquisitions were serially obtained over 15 min. Propofol and methohexital anesthesia caused an average 15% decrease in mean arterial pressure, associated with a 20% decrease in cardiac index without a decrease in systemic vascular resistance index. It is interesting that the determinants of these hemodynamic effects were different. Heart rate did not change during propofol infusion despite the decrease in mean arterial pressure, whereas heart rate increased during methohexital infusion. In the propofol group, the decrease in cardiac index was associated with decreases in indicators of preload (end-diastolic volume and pulmonary capillary wedge pressure), whereas end-systolic volume and global ejection fraction did not change statistically. In the methohexital group, the decrease in cardiac index was associated with a decrease in global ejection fraction and an increase in end-systolic volume, whereas indicators of preload remained unchanged. It is concluded that methohexital reduces left ventricular performance. In contrast, propofol preserves left ventricular performance despite a likely negative inotropic effect.
Recent studies have shown that mitoxantrone is effective in patients with active multiple sclerosis (MS) and that cardiac monitoring is usually required. However, right and left ventricular ejection fractions (VEFs) have never been studied in MS patients as compared with control subjects. Radionuclide angiocardiography (RA) was performed to assess right and left VEFs at rest in 40 consecutive patients with active definite MS [15 men and 25 women; mean age 33.9 +/- 10 years; mean disease duration 8 +/- 6.5 years; 18 had relapsing-remitting and 22 had secondary progressive forms of the disease; mean Expanded Disability Status Scale (EDSS) score 4.8 +/- 1.9]. The control group consisted of 40 subjects free of neurological or cardiovascular disease (17 men and 23 women; 44.6 +/- 13.4 years of age). The VEF values obtained in the control group defined the normal limits (right VEF 32-54%; left VEF 50-74%). A statistically significant decrease of right (P=0.02) and left (P < 0.0001) VEFs was found in MS patients as compared with control subjects. RA showed pathological results for right (7.5%), left (10%) and both (7.5%) VEFs in 25% of MS patients. No correlation was found between VEF and sex, age, disease duration, disease course, EDSS score or previous treatment. Autonomic impairment, which frequently occurs in MS patients, may have accounted for the decrease in VEFs. Further physiological studies are required to determine factor responsible for the decrease of VEFs in MS.
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