Abnormalities of cardiac function, with high intraventricular filling pressure and low cardiac output, play a central role in patients with heart failure. Agents with inotropic properties are potentially useful to correct these abnormalities. However, with the exception of digoxin, no inotropic agent has been associated with favourable effects on outcomes. This is likely related to the mechanism of action of current agents, which is based on an increase in intracellular cyclic adenosine monophosphate and calcium concentrations. Novel agents acting through different mechanisms, such as sarcoplasmic reticulum calcium uptake, cardiac myosin and myocardial metabolism, have the potential to improve myocardial efficiency and lower myocardial oxygen consumption. These characteristics might allow a haemodynamic improvement in the absence of untoward effects on the clinical course and prognosis of the patients