Plasma Catechol Amine Concentrations in Myocardial

Urinary catechol amines have been shown to be increased in a few cases of acute myo-cardial infarction. The present study shows that patients with acute myocardial infarc-tion and with angina pectoris (after exercise) have an increase in plasma catechol amines as compared to normal subjects before and after exercise and as compared to patients with noneardiac types of pain. The significance of these findings is discussed. T HERE have been many reports that the adrenergic eateehol amines (epinephrine and norepinephrine) cause a wastage of oxy-gen by the heart muscle that exceeds the si-multaneous oxidative energy requirements for mechanical work. Recently, however, Katz ' suggested a "stress-adapting mecha-iiisms " related to the catechol amines that ap-pears to make the heart more efficient in the utilization of oxygen in the experimental ani-mal. In either event with cases of myocardial infarction or angina pectoris an excess of these amines may be of cliinical significance. Raab, ' 3 utilizing a modification of Shaw's colorimetric method, showed an increase in blood catechol amines in 7 patients with an-gina after exercise as compared to 14 normal cases. However, this method has subsequent-ly been shown to be insufficiently sensitive to measure minute quantities in blood.4 Nuzum and Bisehoff5 found increased amounts of epinephrine in the urine of 2 patients with myoeardial infarction and 1 of these showed such amounts on 4 occasions. Raab and Gigee,6 on the other hand, were unable to de-tect grossly abnormal total urinary catechol excretion in patients with myocardial infarc-tion, arterial hypertension, congestive failure or in states of emotional tension. They7 per-formed colorimetric determinations of total eatechol amine content and bioassay of nor-epinephrine and epinephrine separately in 8