- Patient's HF is refractory or relatively refractory to usual non-IV medications, as defined by having received one of the two following regimens for the treatment of HF in that last 60 days: 2 complete IV infusions, each lasting at least 2 hours, of either vasoactive (drugs having an effect on veins or arteries) or inotrope medications (drugs that makes the heart works better), or 3 IV diuretic (drugs that increase the elimination of urine) treatments