E.C.G. CHANGES IN DOGS COOLED AFTER HÆMORRHAGE

D. Panteli ¹, E. Vajs ¹, V. Magazinovi ¹, and R. Debijadji ¹

¹ Institute of Pathophysiology, Military Medical Academy, Belgrade, Yugoslavia

Experiments have been done to determine the effect of hypothermia on dogs previously subjected to hypotension induced by hæmorrhage. After 1 hr. of hypotension two groups of dogs were cooled to 28° C. and 31° C. respectively and then left for 2 hr. at room temperature (24° C.). Seven out of nineteen died of ventricular fibrillation. On rewarming six more died after some hours. The E.C.G. (Lead II) changes during hypothermia were much the same as those found in cooled normal dogs. The E.C.G. changes due to hæmorrhage were similar to those found in dogs subjected to hæmorrhage at normal temperatures superimposed on the hypothermic E.C.G. patterns. Below 25° C. it was sometimes difficult to decide on the relative preponderance of the two effects. The only difference between survivors and those dogs which died was the greater incidence of the "Osborn wave" in the E.C.Gs. of the latter. However, there is no evidence that the appearance and behaviour of this wave can be taken either as a sign of a poor prognosis or as a warning of impending ventricular fibrillation.