Cardiotoxic effects of the venom of the burrowing asp, Atractaspis engaddensis (Atractaspididae, Ophidia).

The venom from the snake Atractaspis engaddensis has a very high lethal potency, with an i.v. LD50 of 0.06-0.075 micrograms per g body weight in mice. The action of the venom is rapid and death results from seemingly neurotoxic effects. However, even at high concentrations, the venom does not block contractions of skeletal muscles that are directly or indirectly stimulated. The most prominent action of the venom is seen in the function of the heart in anesthetized mice, with or without artificial respiration. The changes observed in the ECG are similar to those recorded in human victims and are the result of an A-V block that is caused by an apparent direct action of the venom on the heart.