devices and methods for delivering therapeutic or diagnostic agents to a target tissue of a human body are disclosed . a catheter in accordance with the present invention includes an elongate shaft having a distal end , a proximal end , and a lumen therethrough . the elongate shaft includes a first curved portion proximate the distal end of the elongate shaft . the first curved portion of the elongate shaft defines a first plane . the elongate shaft also includes a second curved portion disposed between the distal end of the elongate shaft and the first curved portion of the elongate shaft . the second curved portion of the elongate shaft defines a second plane . the second plane intersects the first plane at an angle .