Observations on isolated heart at lowered temperature.

Various ograns under condition of hypothermia undergo a marked change in their response, both to physiological and pharmacological stimuli although the e:uct mechanism underlying this alteration yet remains unex· plained. As a result of more generalised use of induced hypothermia as an adjuvant in cardiac surgery, it was noted that lowering of body temperature predisposes to cardiac arrhythmias and surgical shock. Jouvenelles et al (1954) observed a definite involvement of the heart during cooling, and it was a common experience of the workers in the field that one of the real dangers in hypothermia was the tendency on the part of myocardium to go into ventricular fibrillation,