Effects of chronic guanethidine administration on cardiovascular function of dogs

Chronic guanethidine administration 2.5 mg/kg/day for 7 to 8 months did not produce any essential changes in blood pressure and heart rate of the anesthetized dogs while there was a significant elevation of stroke volume and stroke work. There was a reduction in total peripheral resistance and an increase in cardiac output in the treated dogs in comparison with the placebo group. Ventricular function curves obtained in both the treated and placebo group were virtually identical. The data suggested that chronic guanethidine administration did not induce any adverse effect on myocardial functions.