Effect of Thiamine Deficiency on Potential Myocardial Contractility

Abstract

After rats had been on a thiamine free diet for five weeks their myocardium in vivo showed a marked decrease (69%) of developed isometric tension. During the first two weeks on a thiamine free diet developed tension was within the control range; but by three weeks the developed tension and myocardial response to epinephrine were much diminished. The susceptibility of these animals to arrhythmias was increased markedly. The incidence of arrhythmias increased as the length of time on the thiamine free diet increased. In many instances terminal ventricular fibrillation occurred. The decrease of myocardial tension or potential contractility occurring in thiamine deficiency may be attributed, at least in part, to interference with energy liberation due to a reduction in the level of cocarboxylase which limits the utilization of carbohydrate by the myocardium.