Effect of body hypothermia on transventricular simple-capacitor-discharge defibrillation thresholds

Abstract:

In 260 successful transventricular simple-capacitor-discharge defibrillations performed on 20 mongrel dogs under conditions of body hypothermia, and overall average peak current threshold of 69.5 mA/g of heart (SD 30.4) was found. This value, when compared by means of the unpaired t test with previous data obtained under conditions of relative normothermia (89.5 mA/g of heart, SD 32.8, 346 defibrillations, 20 dogs) yielded a highly significant difference (P<<0.1%). When comparing the deviation of the regression equation (current vs. temperature) from the horizontal line, the Snedecor F test gave also a high level of significance (P<<1%). These results led to the conclusion that body hypothermia significantly reduces transventricular defibrillation thresholds. After normalizing the regression equations, this reduction was found to be on the average equal to 4.1%/°C (SD 1.4) for current and to 5.9%/°C (SD 1.4) for energy over the 20 dogs. In all animals, the coefficient for variation was greater for energy than for current (about twice as much), suggesting that current is a better descriptor of what is needed for electrical defibrillation. The transventricular impedance was rather constant, yielding an overall average of 28.5 Ω (SD 6.0).

Año de publicación:

1980

Keywords:

Fuente:

scopus