Effect Of Ligation Of Spleen Vessels On Left Ventricular Function And Coronary Blood Flow In Dogs Injected With Scorpion Venom

Scorpion sting may cause myocardial dysfunction in human victims, probably by increased O₂demand and decreased O₂supply. In dog, scorpion venom (SV) causes no myocardial dysfunction. Myocardium is probably protected by “autotransfusion” of blood from the spleen to the circulation, increasing coronary blood flow (CBF) and O₂delivery. We hypothesized that ligation of spleen vessels prior to injection of SV in dogs would prevent the autotransfusion of blood, thereby causing myocardial ischemia due to decreased CBF, simulating the hemodynamic pattern of human envenomation. We studied cardiac output (CO), CBF, left ventricular (LV) O₂delivery and contractility in 11 dogs injected with 0.07 mg/kg of SV (Leiurus quinquestriatus). Ligation of spleen vessels was performed on 6 of the 11 dogs prior to SV injection. 15 min after SV injection CO had increased by 186% in control dogs, while ligation of spleen vessels completely prevented CO elevation (p<0.001). In both groups, however, LV dp/dt increased by 400% and dp/dt/p by 170% (p<0.001).