Concentration of catecholamines in human cardiac muscle.

A trihydroxyindole fluorescent technique was used to measure the concentration of catecholamines in heart muscle taken from 42 patients undergoing open heart surgery. Noradrenaline was the dominant catecholamine and its depletion in the failing heart was confirmed. The distribution of catecholamines within the heart was such that the highest value, 2.64 +/- 0.68 microgram/g, was found in the nonfailing right atrium and the lowest, 0.53 +/- 0.40 microgram/g, in the failing left ventricle.