A device for fracturing calcifications in heart valves characterised by a stabilizer assembly and an impactor assembly assembled on and deployed by a delivery system wherein said delivery system is operable to cause relative motion between said impactor assembly and said stabilizer assembly with sufficient energy so as to fracture a calcification located in tissue which is sandwiched between said stabilizer assembly and said impactor assembly wherein said impactor assembly and said stabilizer assembly have shaped impact delivery portions of which the footprint on the valve leaflets is shaped in accordance with a shape of desired fracture sites.
