Myocardial catecholamine concentrations in dilated cardiomyopathy and heart failure of different origins.

Myocardial catecholamine concentrations were determined in endomyocardial biopsies from patients with heart failure to assess if tissue catecholamine levels relate to the severity of myocardial damage or the aetiology of the underlying disease. Methodological studies revealed a good reproducibility of catecholamine determinations in biopsies; the variance between paired biopsies was below 17% when myocardial catecholamines were related to non-collagen protein (NCP). Myocardial norepinephrine (in pg micrograms-1 NCP) levels were comparable in patients with dilated cardiomyopathy (DCM, 5.3 +/- 3.4, n = 22) and in patients with coronary or valvular heart disease (5.6 +/- 4.7, n = 14). In both groups, a significant reduction of myocardial norepinephrine was found (controls 12.0 +/- 3.4, P less than 0.0006). In a subgroup of patients with heart failure and a LVEF less than 30% (3.9 +/- 3.5, n = 17) myocardial norepinephrine content was lower than in patients with heart failure and LVEF of 31-55% (6.6 +/- 3.4, n = 19) (both P less than 0.05 against controls: 12.0 +/- 3.4, n = 16). A correlation between myocardial norepinephrine and LVEF was found in DCM (P less than 0.001, r = 0.70). The loss of myocardial norepinephrine is a characteristic feature of heart failure. It is independent of the origin of failure, but correlates with the impairment of LV function.