Induced Pressure Gradients Across Infundibular Zone of Right Ventricle in Normal Dogs

Abstract
In these experiments we have demonstrated that: 1. Right ventricular outflow-tract pressure gradients of significance can be induced in normal dogs by a sympathomimetic amine which increases the rate and force of ventricular contraction. 2. Such outflow-tract pressure gradients are magnified by the addition of other inotropic drugs, such as acetyl strophanthidin and calcium chloride. 3. These outflow-tract pressure gradients are not the result of an increase in the volume and rate of blood flow but are due to forceful contraction of the infundibulum.