Cardiovascular function in potassium-depleted dogs

Abstract

Chronic potassium depletion in the dog is associated with multiple cardiovascular alterations. The rate of automaticity of the S-A node appears diminished and its response to a chronotropic stimulus is impaired. The reduced peripheral resistance causes a decline in the characteristic hypertensive response to pentobarbital anesthesia. Cardiac function is not impaired, in the absence of arrhythmias, and contractility seems enhanced since potassium depletion produces a significant increase in the mean systolic ejection rate, a rise in LV dp dt , and a higher LVSW and a trend to increased LVMW at similar levels of LVEDP. These hemodynamic alterations are not associated with light microscopic changes in cardiac muscle.