Amrinone is primarily used as a positive inotropic agent in the treatment of congestive heart failure. It works by inhibiting phosphodiesterase, which increases the levels of cyclic AMP in cardiac cells, leading to enhanced myocardial contractility and vasodilation. This dual action helps to improve cardiac output and reduce the workload on the heart. It is typically administered intravenously in acute settings, such as in patients with severe heart failure who are not responding adequately to other treatments like digoxin or diuretics. Additionally, Amrinone can be used in the management of low cardiac output states following cardiac surgery, where it aids in stabilizing hemodynamics and improving perfusion to vital organs. Its use is closely monitored due to potential side effects, including arrhythmias and hypotension.