Rotational atherectomy devices and systems can remove or reduce stenotic lesions in blood vessels by rotating one or more abrasive elements within the vessel. The abrasive elements are attached to a distal portion of an elongate flexible drive shaft that extends from a handle assembly that includes a driver for rotating the drive shaft. In particular implementations, individual abrasive elements are attached to the drive shaft at differing radial angles in comparison to each other (e.g., configured in a helical array). The centers of mass of the abrasive elements can define a path that spirals around the drive shaft in a direction that is opposite to the wind direction of filars of the drive shaft, and opposite to the direction of rotation. In some embodiments, a concentric abrasive tip member is affixed to and extends distally from a distal-most end of the drive shaft.