To the Editor.—
Two features attributed to involvement of the autonomic nervous system in acute episodes of hepatic porphyria are abdominal pain and tachycardia at rest.1-4 In normal persons, atropine sulfate increases the pulse rate through inhibition of vagal action,5,6 but if there is damage to the parasympathetic cardiac fibers the pulse rate is not modified.7 In two cases of porphyria, we observed the effect of intravenous (IV) atropine on the tachycardia.
Report of Cases.—
Case 1.—A 31-year-old woman had sudden abdominal pain closely resembling that of an acute abdominal condition. At the time of exploratory laparotomy, only dilated intestinal loops and urinary bladder were found. There was no alteration of consciousness. The cranial nerves and optic fundi were normal. Strength was normal, as were reflexes. Babinski's sign was absent. Sensation was normal. Motor nerve conduction velocities were as follows: median nerve, 66 m/s; ulnar nerve, 62
Idiaquez J. Effects of Atropine on Pulse Rate in Acute Hepatic Porphyria. Arch Neurol. 1982;39(11):737. doi:10.1001/archneur.1982.00510230063022
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