[The effect of hypothermia on the wavelength and vulnarability to ventricular arrhythmias in mammals].
Arrhythmias developing in isolated Langendorff-perfused heart following the cooling of the perfusion solution from +37 to +3 degrees C were studied in rats and winter hibernating ground squirrels Citellus undulatus with application of no drugs. In rats, hypothermia significantly increased the probability of ventricular arrhythmias (from 22 +/- 6 % at 37 degrees C to 56 +/- 14 % at 17 degrees C). Excitation failure was observed in the rat hearts below 10 +/- 1 degrees C. The appearance of arrhythmias was closely correlated with a decrease in the wavelength which strongly suggests a reentrant mechanism of the hypothermic arrhythmias. In contrast, ground squirrels showed insensibility of the wavelength to cooling and were resistant to arrhythmias during hypothermia.
Glukhov
A V
AV
Egorov
Iu V
IuV
Fedorov
V V
VV
Efimov
I R
IR
Rozenshtraukh
L V
LV
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000503:physiopathology*; D006352:Heart Ventricles / Q000503:physiopathology; D006605:Hibernation; D007035:Hypothermia / Q000503:physiopathology*; D009924:Organ Culture Techniques; D051381:Rats; D017208:Rats, Wistar; D012589:Sciuridae; D013045:Species Specificity