REDUCED CARDIAC EXTRACTION OF NOREPINEPHRINE AND EPINEPHRINE IN PATIENTS WITH HEART-FAILURE - CORRELATION WITH LEFT-VENTRICULAR FUNCTION

To assess whether the impairment of neuronal norepinephrine (NE) uptak e is involved in the increased NE release observed in the failing hear t, we examined the cardiac extractions of NE and epinephrine (E) and t heir correlation with left ventricular function in 16 patients with an terior transmural old myocardial infarction (OMI) and 18 patients with dilated cardiomyopathy (DCM). The plasma NE and E levels were both in creased in OMI and DCM, particularly in the coronary sinus, as compare d with those in 16 control subjects (Control). The cardiac NE and E ex tractions were significantly reduced in OMI (P < 0.001) and in DCM (P < 0.001) as compared with those in the Control (NE: -38 +/- 36% in OMI , -33 +/- 28% in DCM, and 14 +/- 18% in Control; E: 30 +/- 12% in OMI, 32 +/- 17% in DCM, and 54 +/- 8% in Control). However, there was no r eduction in the NE and E extraction in the leg in OMI and DCM. Cardiac NE and E extractions both showed significant correlation with the lef t ventricular ejection fraction (r = 0.685, P < 0.001 and r = 0.609, P < 0.001, respectively). We conclude that, in patients with heart fail ure, NE release from the heart is increased partially due to the reduc tion of the cardiac; neuronal uptake of NE which is proportional to th e severity of left ventricular dysfunction.