Myocardiopathies and tricyclic antidepressants. Apropos of 3 cases

: The authors report three cases of cardiac failure induced or aggravated by chronic tricyclic antidepressant therapy. Tricyclic antidepressants have a negative inotropic effect both when administered acutely or chronically in animals. This action is related to plasma concentrations. However, the association of chronic tricyclic antidepressant therapy and cardiac failure is rare. The implication of these drugs in the cause of cardiac failure requires: --improvement of cardiac failure on withdrawal of therapy, as observed in our three cases; --the presence of underlying cardiac disease, as was the case in our patients; --abnormally high plasma levels of the antidepressant drugs despite normal dosage, as was verified in two of our patients. The measurement of plasma concentrations of antidepressant drugs would seem to be necessary when this form of treatment is to be administered to patients predisposed to cardiac failure.