In a balloon catheter for introduction into a body vessel, in particular the coronary sinus, and for intermittently occluding the same, comprising a catheter shaft (155) that carries an inflatable balloon (122) on a distal end portion and a plurality of lumens extending through the catheter shaft (155), a pressure sensor lumen (125) extending centrally through the catheter shaft (155) to at least one distal opening (127,128) is provided, the at least one distal opening (127, 128) being arranged distally of the balloon (122) for communication with the fluid in the body vessel. Furthermore, an inflation lumen (158) to inflate and deflate the balloon (122) is provided, wherein the catheter comprises a stiffening element (123) extending along the catheter shaft (155), the stiffening element (123) having a distal end portion (164) that is positioned adjacent to the proximal end of the balloon (122) and has a flexural strength reduced relative to a remaining portion of the stiffening element (123).
