Systemic and regional hemodynamics after coronary embolization in closed chest dogs

Cardiogenic shock was produced by the mercury embolization technique in closed chest anesthetized dogs. Hemodynamics and flow in the renal, superior mesenteric, and femoral arteries were measured serially for 3 hr after embolization. Mean arterial pressure fell 34% and cardiac output 44% by 30 min, whereas total peripheral resistance was increased only 7%. A 60 min. total peripheral resistance began rising significantly to 114% (P < 0.001) above control by 3 hr. Cardiac output fell further at this time to 66% (P < 0.001) below control after 3 hr. Superior mesenteric arterial flow fell significantly (21%, P < 0.01) in the first 15 min, and continued dropping parallel to cardiac output thereafter. Superior mesenteric resistance did not rise until 2 hr after infarction but rose to 96% (P < 0.02) above control level by 3 hr. Renal arterial flow was unchanged after 30 min, whereas renal resistance was reduced; flow subsequently fell progressively as resistance increased. Femoral arterial flow and resistance were not changed significantly. An early phase of inhibited vasoconstriction in experimental cardiogenic shock is followed by a period of marked vasoconstriction associated with generalized circulatory deterioration.