Hemodynamic effects of
hypotension induced by
ketanserin were investigated in 18 mongrel dogs under 0.87%
halothane in
oxygen (1 MAC). They were randomly allocated to one of two groups. Group C (n = 9) received no
vasodilator therapy and served as a control and group K (n = 9) received 0.1%
ketanserin solution. Mean arterial pressure decreased and was maintained at 60 mmHg for 60 minutes in group K. No change was noted in hemodynamic variables measured in group C throughout the experiment. During and after
induced hypotension in group K, stroke volume index increased significantly compared with the control value. On the other hand, systemic vascular resistance was significantly reduced, reaching 50% of the control value at the end of the hypotensive period. Left ventricular maximum dp/dt showed a significant reduction during
hypotension but then increased gradually to the control value. In addition, heart rate decreased significantly during and after
induced hypotension, therefore these
vasodilator effects were not accompanied by reflex
tachycardia. Cardiac index remained unchanged throughout the experiment. Further, no changes in central venous pressure, mean pulmonary artery pressure, pulmonary capillary wedge pressure and pulmonary vascular resistance were observed. In conclusion, the data indicate that
ketanserin is a potent systemic
vasodilator producing stable hemodynamics. It also reduces systemic vascular resistance without reflex
tachycardia and this is a favorable effect of
ketanserin.