Action of Atropine on the Turtle Heart

Abstract

Summary

The direct action of atropine on cardic muscle has been studied in the whole auricle and ventricular strips of turtle heart. In concentrations far above those that could be used therapeutically, its affect on rhythmicity, contractility, absolute refractory, contractility, absolute refractory period, tonus, and on conductivity at low rates of beating was slight and inconstant. The only significant direct action of atropine on heart muscle appears to be a power to depress conductivity at relatively high rates of beating.