[Cardiovascular changes caused by atropine in normo- and hypothermic methoxyflurane anaesthesia (author's transl)]

The authors examined in 25 patients, of which 15 were normo- and 10 in hypothermic, the cardiovascular effects of 1 mg atropine i.v. In normothermia the heart rate increased significantly from 100 to 110 beats/min after atropine. At the same time the stroke index and stroke work decreased significantly. The mean arterial pressure, the heart index, the left ventricular minute- and stroke work and the total peripheral resistance did not change. In two patients with an arteriovenous fistula and hypervolaemia, the atropine injection caused an increased of heart- and stroke index. Arrhythmias did not occur after atropine. In hypothermia on the other hand atropine was shown to have no effect on heart frequency and all other examined parameters. In one patient in which the P-R interval was shortened, the atropine injection was followed by an total atrio-ventricular block. The authors cannot recommend atropine therapy in cases of hypothermic bradycardia, because of its lack of effect on the heart rate in hypothermia.