A valvuloplasty balloon assembly includes a balloon (50) provided with end shoulders (64, 66) preferably integral with end cones (54, 56) of the balloon (50). The end shoulders (64, 66) provide a substantially perpendicular stop shoulder (68) at either end of the cylindrical portion (52) of the balloon (50). The restraining shoulders (64, 66) act to hold the balloon (50) within a valve (16) of a heart (10), for instance. This prevents unwanted slippage of the balloon (50) during a valvuloplasty procedure and thus prevents possible damage caused as a result of such slippage.
