The aim of this thesis was to assess t e role of ibopamine, in the treatment of patients with heart failure. Ibopamine is an orally active dopamine agonist which has beneficial hemodynamic and neurohumoral effects. In the 10 Appendices both clinical and experimental studies are reported that were designed to examine the efficacy and safety of ibopamine. The clinical studies, which constitute Appendices 1-7, were conducted in patients with mild, moderate and severe heart failure. In these studies, we evaluated the influence of ibopamine on hemodynamics (Appendices 3,4,6), renal function (Appendices 5,6), neurohumoral parameters (Appendices 1,2,3), arrhythmias and electrophysiology (Appendices 1,3), exercise tolerance (Appendices 1,2), signs and symptoms of heart failure and side-effects (Appendices 1,5,7). ... Zie: Summary and conclusion