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Alterations in norepinephrine content and beta adrenoceptor regulation in myocardium bordering aneurysm in human heart: their possible role in the genesis of ventricular tachycardia
Author(s) -
BEVILACQUA M.,
NORBIATO G.,
VAGO T.,
MERONI R.,
DAGANI R.,
RAGIG U.,
FRIGENI G.,
SANTOLI C.
Publication year - 1986
Publication title -
european journal of clinical investigation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.164
H-Index - 107
eISSN - 1365-2362
pISSN - 0014-2972
DOI - 10.1111/j.1365-2362.1986.tb01324.x
Subject(s) - medicine , norepinephrine , cardiology , myocardial infarction , ventricular tachycardia , heart failure , papillary muscle , adrenergic receptor , adrenergic , endocrinology , tachycardia , aneurysm , ventricular aneurysm , receptor , surgery , dopamine
. On the assumption that alterations in the adrenergic system may play a role in generating ventricular tachycardia in patients with myocardial post‐infarction apical aneurysm, we evaluated norepinephrine concentration, number and affinity of both beta 1 and beta 2 adrenoceptors in perianeurysmatic tissue in twelve patients operated upon for congestive heart failure and recurrent sustained ventricular tachycardia. Concentration of norepinephrine in perianeurysmatic tissue was 0·1 ± 0·05 μg g ‐1 tissue ( n = 8), this value being much lower than that found in papillary muscle ( n = 10) from patients with mitral valve stenosis (0·8 ± 0·02 μg g ‐1 tissue) ( P < 0·01). The total number of beta adrenoceptors (71·4 ± 7·8 v. 48·0 ± 5·1 fmol mg ‐1 protein; P < 0·01) and the percentage of beta 1 subtype were found to be higher in perianeurysmatic tissue (˜90%) than in papillary muscle (˜68%). Out of twelve patients with aneurysm, beta 2 adrenoceptors had considerably decreased in three patients and were absent in the remaining nine. Decrease in the neuronally released norepinephrine associated with contrasting behaviours of beta 1 and beta 2 adrenoceptors suggests the presence of a profound alteration in the sympathetic innervation of the perianeurysmatic myocardial tissue that may contribute to the genesis of sustained ventricular tachycardia in patients with post‐infarction apical aneurysm.