Effect of niacinamide on cardiac output, cardiac excitability and membrane action potential of single cardiac muscle fibers

¹ Department of Physiology, State University of New York, Downstate Medical Center, Brooklyn, New York

The actions of niacinamide on cardiac output and cardiac excitability of the dog heart and on the action potentials of individual frog ventricle cells were recorded. Cardiac output was increased. The duration of the action potentials of frog heart cells and the refractory period of the dog heart were shortened significantly. This drug increases respiratory and circulatory action chiefly through a stimulatory action on the heart.