[Catecholamines for treatment of severe heart failure (author's transl)].

In patients with severe heart failure there is increased sympathetic-adrenergic activity functioning as a compensatory mechanism. Despite of increased plasma catecholamine levels myocardial sensivity to catecholamines administered for therapeutic reasons is not diminished. The positive inotropic effect of catecholamines is more pronounced as compared to digitalis glycosides. The therapeutic efficacy of catecholamines, particularly their capability to increase cardiac output, is strongly dependent on their action on alpha- and beta2-receptors. In order to enhance cardiac performance, catecholamines are mainly used under three clinical settings: 1. severe heart failure and cardiogenic shock secondary to acute myocardial infarction, 2. 'Low cardiac output syndrome" following cardiac surgery, and 3. chronic congestive heart failure refractory to therapy with glycosides and diuretics. The use of catecholamines in the presence of acute myocardial infarction may be hazardous due to the accompanying increase of myocardial oxygen consumption. Among the available catecholamines, clinical interest recently focused on dopamine and dobutamine. Particularly with the primarily cardioselective beta-stimulating agent dobutamine a marked positive inotropic effect can be achieved in a range of dosage not significantly affecting heart rate and peripheral resistance. Positive inotropic agents may be even more effective when used in combination with vasodilators, which decrease impedance to left ventricular ejection.