[Metabolism of myocardial catecholamines and plasma catecholamine levels in patients with chronic aortic regurgitation (author's transl)].

In 17 patients suffering from severe chronic aortic regurgitation (class III N.Y.H.A.), during aortic valve replacement right atrial biopsies were taken. In these samples myocardial content of norepinephrine, normetanephrine, epinephrine and dopamine were determined. 2-4 days before valve replacement, plasma catecholamines were measured at rest and during isometric exercise. 15 patients with atrial septum defect (foramen secundum) served as controls. In patients with aortic regurgitation demonstrating no clinical signs of cardiac failure, myocardial content of norepinephrine, normetanephrine and epinephrine was significantly reduced compared to tissue content of patients with atrial septum defect. Right atrial content of dopamine did not reveal any difference between the two groups. In all patients, plasma catecholamines at rest were within normal limits. During isometric exercise, however, the increase of plasma norepinephrine in patients with aortic regurgitation was significantly higher compared to the control group. It is concluded from these data that patients with aortic regurgitation, demonstrating an exaggerated increase in sympathetic activity during exercise, probably show a decrease in myocardial norepinephrine tissue content. Therefore, clinical demonstration of hyperadrenergic response during exercise represents a simple metabolic parameter indicating alteration in myocardial metabolism in patients with chronic aortic incompetence. Since decision for aortic valve replacement should be done before irreversible damage of myocardium has established, it is supposed that assessment of sympathetic activity, at rest and during exercise, may reveal practical clinical importance.