The use of vasodilators represents a new approach to the treatment of cardiac insufficiency, either chronic or acute. Their field of action is venous, arterial or mixed. Decreasing the pre-load, the "venous" vasodilators lighten the congestive symptoms of cardiac insufficiency. By decreasing the post-load, the "arterial" vasodilation increases the cardiac output. Some vasodilators, venously administered, imply a continuous hemodynamic checking (Sodium Nitroprussiate, Phentolamine, injectable Trinitrine). Others are active orally (Trinitrine, Isosorbide Dinitrate, Hydralazine, etc.). Vasodilating treatment is recommended for acute cardiac insufficiency, particularly during myocardium infarct and some acute valvular insufficiencies. It is also successfully used in acute lung edema. Finally it takes an increasing importance in the treatment of chronic cardiac insufficiency.