Preview Selection of therapy for patients with systolic cardiac dysfunction must be predicated on careful assessment of the delicate interplay between the failing heart and the state of effective circulating blood volume. In this article, the authors discuss the drugs that improve systolic function and effective circulating volume and, ultimately, enhance tissue perfusion in vital organs such as the kidney. A companion article on page 141 explains the renal and neurohumoral events that occur in patients with systolic heart failure.