Study on the effect of gastric freezing on cardiovascular system
Since the introduction of gastric freezing for the treatment of peptic duodenal ulcer in 1962 by Wangensteen, there has been a considerable controversy on this physiological gastrectomy and the complications associated with it.
At first, the method was received with such enthusiasm that an estimated 1,000 gastric freezing machines were purchased in the United States and the stomachs of about 15,000 patients were frozen in 2 years (White et al., 1964).
Wangensteen, S.L. (1965) found that gastric hypothermia in the treatment of patients with duodenal ulcer caused an early symptomatic improvement and a depression in the hydrochloric acid secretion, but without long term benefit. But Perry et al. (1964) reported no significant difference in respect to symptomatic
relief or gastric secretion in a "double blind study". Gastric freezing has different side effects and complications. DeForet (1964), in excellent review of 826 patients, showed that, only one had died, 70 (8.5%) had developed melena and 21 (2.5%) had developed clinical gastric ulcer. Anatomically the heart is located near the fundus of the stomach, so that local freezing of the stomach may induce various effects on the heart. Evidence of myocardial ischemia has been noted by Karcadag and Klotz (1964), as manifested by electrocardiographic changes of inverted T-waves
and ST segment depressions during the procedure. Garcia et al. (1965) reported that the degree of alteration of the electrocardiographic pattern appeared to be related to the degree of hypothermia.
On the basis of these considerations, this investigation was undertaken to study 1) changes of body temperature, 2) changes in heart rates, 3) effects of blood pressure and 4) changes in electrocardiographic tracings, before, during and after gastric freezing. The technique of gastric freezing, as described by Wangensteen et al. (1962) was used.
The results obtained may be summerized as follows;
1) The rectal temperature of the experimental dogs fell progressively during the procedure. The average rectal temperature of 37.8℃ before freezing decreased to 30.0℃ when the procedure was completed in the experimental dogs. The lighter the dog's weight, the more its rectal temperature decreased.
2) As the procedure continued and the body temperature decreased, the heart rate of experimental dogs slowed down progressively. The average heart rate of 190 a minute before the procedure slowed down to 110 a minute when the procedure was
completed in the experimental dogs.
3) The mean femoral arterial pressure by direct mercury manometer in the 6 experimental dogs was not significantly lowered during the procedure, without regard to a slower heart rate or to a lowered rectal temperature, except in a dog whose rectal temperature was down to 27.0℃ at the completion of the procedure.
4) During the gastric freezing, electrocardiographic changes showed flattening or diphasic T-waves in 9 dogs, depression of ST segments in 7 dogs, especially in lead Ⅱ, Ⅲ and aVF. and as the rectal temperature fell, electrocardiographic patterns showed a slowing heart rate and prolongation of the QT interval, except in
a dog which had supraventricular tachycardia. Supraventricular tachycardia occured in one of the 16 experimental dogs in the early stage of gastric freezing (when it rectal temperature at onset was 36.0℃ and it returned to a noraml sinus rhythm after the gastric freezing.