Simendan is primarily used in the treatment of acute decompensated heart failure. It works by enhancing cardiac contractility and promoting vasodilation, which helps improve heart function and reduce symptoms such as shortness of breath and fatigue. This dual mechanism of action makes it particularly useful in managing patients with severe heart failure who require immediate therapeutic intervention. Additionally, it is often administered in hospital settings under close medical supervision to monitor its effects on heart rhythm and blood pressure. Its ability to provide both inotropic and vasodilatory effects makes it a valuable option in critical care scenarios.