An introducer sheath for percutaneous insertion of a heart pump includes a tubular sheath body having a wall, a proximal end portion, a distal end portion, and an inner lumen. The introducer sheath includes a hemostatic valve disposed in the proximal end portion and forming a liquid tight seal across the inner lumen of the tubular sheath body. The hemostatic valve includes a valve cavity having a distal end and a proximal end, a first annular restriction formed within the valve cavity and having a first diameter, and a second annular restriction formed within the valve cavity distal to the first annular restriction and having a second diameter. The distal end of the valve cavity is spaced from the second annular restriction by a gap distance and a third diameter of the valve cavity along the gap distance is about equal to or greater than the first and second diameters.
