American Journal of Clinical Nutrition, Vol 27, 136-143, Copyright © 1974 by The American Society for Clinical Nutrition, Inc.

Ventricular performance, coronary flow, and myocardial oxygen consumption in rats with advanced thiamin deficiency

¹ From the Department of Pediatrics, Harvard Medical School and the Cardiology Department, Children's Hospital Medical Center, Boston, Massachusetts 02115

With the use of an isolated, supported, blood perfused rat heart preparation, left ventricular performance, coronary flow, and myocardial oxygen consumption were observed in the hearts of rats with advanced thiamin deficiency and in those of normal control rats. All thiamin-deficient animals showed signs of thiamin deficiency by extreme weight loss (23 to 47%), perioral abrasions, lethargy, and ataxia. No difference was found between the ratio of left ventricular weight to body weight in the thiamin-deficient animals when compared with controls. Ventricular performance as determined by the end-diastolic pressure required to develop a given systolic pressure in the isovolumically contracting heart was comparable in the control and thiamin-deficient groups. When the ventricles were developing high ventricular pressures both coronary flow and myocardial oxygen consumption were significantly greater at comparable systolic pressures in the hearts from thiamin-deficient animals. These findings are consistent with the hypothesis that the primary cardiovascular effect of advanced thiamin deficiency in the rat is largely through its effect on the peripheral circulation. Some evidence, however, is provided that a lack of this vitamin directly affects the myocardium so as to cause an increase in its oxygen need.