The invention provides a rotational atherectomy system, device and method having, in various embodiments, a flexible, elongated, rotatable drive shaft with at least one eccentric abrading head attached thereto, wherein the abrading head comprises at least one groove thereon. The eccentric grooved abrading comprises a tissue removing surface—typically an abrasive surface and/or at least one groove. Preferably the eccentric enlarged abrading head has a center of mass spaced radially from the rotational axis of the drive shaft, facilitating the ability of the device to open the stenotic lesion to a diameter substantially larger than the outer diameter of the enlarged abrading head when operated at high speeds. The groove(s) provide improved efficacy in the abrasion of non-calcified and/or soft tissue as well as provide a means for breaking the hydraulic wedge between the abrading head and the stenotic tissue.