Author + information
- Received May 14, 1984
- Revision received July 30, 1984
- Revision received August 22, 1984
- Published online February 1, 1985.
- Robert A. Slutsky, MD, FACCa and
- Michelle Murray, MD
- ↵aAddress for reprints: Robert A. Slutsky, MD, University of California (H-755), 225 Dickinson Street, San Diego, California 92103.
Using contrast-enhanced computed tomography, the effects of hyperosmolar mannitol and methylprednisolone on experimentally produced myocardial infarcts were evaluated serially over the course of approximately 1 month. Infarct size, initial perfusion defect (jeopardized segment) and noninfarcted muscle mass were determined in three groups of conditioned mongrel dogs. Group 1 (n = 11) served as the control group, groups 2 and 3 were pretreated with mannitol (375 mg/kg, n = 10) or methylprednisolone (7.5 mg/kg, n = 11). Each animal in the treatment groups was treated with identical doses of the originally administered agent twice daily for 7 days after coronary occlusion. Each group developed increases in the noninfarcted muscle mass of the left ventricle (compensatory hypertrophy). The mean increase averaged more than 20% over 30 days when all groups were included together. Infarct size was smaller in both of the treatment groups. However, at 4 days after infarction, mannitol-treated dogs had a mean infarct size that was 68 ± 8% ( ± standard error of the mean) of the size of control infarcts (p < 0.01) and methylprednisolone-treated dogs had a mean infarct size that was 77 ± 6% of the size of control infarcts (p < 0.111) (referenced to the initial perfusion defect). At 30 days, these differences were less substantial (though still significant), 88 ± 4% and 85 ± 5%, respectively.
Pharmacologic interventions can be shown to alter the size of an acute myocardial infarction, particularly when examined over the time course of infarct healing. Importantly, transient reduction in myocardial water content in the first several days after infarction may result in an overestimation of the therapeutic utility of the intervention.
This study was supported in part by the Research Service of the Veterans Administration, the Technicare Corporation (Cleveland, Ohio) and funds from the Society of Nuclear Medicine (Tetalman Memorial Award, New York. New York) and the Association of University Radiologists (Herbert M. Stauffer Award, Washington, D.C.) awarded to Dr. Slutsky.
- Received May 14, 1984.
- Revision received July 30, 1984.
- Revision received August 22, 1984.
- American College of Cardiology Foundation