The invention relates to a feed line (105) for a pump unit (110) of a cardiac support system (100). The feed line (105) is embodied to guide a fluid flow to a pump unit (110) of the cardiac support system (100). The feed line (105) comprises a feed head portion (130) with at least one introduction opening (140) for introducing the fluid flow into the feed line (105) and a contoured portion (135) with an inner surface contour. The contoured portion (135) is disposed adjacent to the feed head portion (130). An inner diameter of the contoured portion (135) at a first position is greater than the inner diameter at a second position. The inner surface contour has a rounded portion at the second position for reducing the inner diameter.