New cardiotonic agents are an original approach in the treatment of severe heart failure. They can be classified into two groups: --beta-adrenergic agonists which stimulate beta-adrenergic receptors and, therefore, increase cyclic AMP production and intracellular calcium concentration; --phosphodiesterase inhibitors which block the cyclic AMP intracellular degradation pathway. Rapid tachyphylaxis may occur with beta-adrenergic agonists through a down-regulation phenomenon and, therefore, limits the value of this group to short-term treatment. Several different biochemical compounds are under evaluation in the second group. Short-term effects appear beneficial but cardiac side-effects may occur. The value and indications of these drugs in long-term treatment of chronic congestive heart failure remain to be determined.