Gastric dilatation-volvulus (at 30 mm of Hg of gastric pressure) was experimentally induced in 8 dogs under sodium pentobarbital anesthesia. Hemodynamic indices including cardiac output, mean aortic pressure, left ventricular end diastolic pressure, heart rate, total peripheral resistance, and dp/dtmax were measured during a 180-minute period of gastric dilatation-volvulus and for 120 minutes after gastric decompression. Experimental gastric dilatation-volvulus resulted in significant (P less than 0.05) decreases in cardiac output (64%), mean aortic pressure (48%), left ventricular end diastolic pressure (68%), and ventricular dp/dtmax (32%) compared to 4 control dogs. Hemodynamic indices returned toward control values after gastric decompression. It was concluded that gastric dilatation-volvulus in the present experiment was capable of inducing hemodynamic alterations of a magnitude similar to those reported in gastric dilatation studies, using higher gastric pressures.