An apparatus for use in mitral valve replacement comprising: a controller comprising a handle having a knob; a cutting section comprising: a tube coupled to the handle of the controller, the tube defining a lumen extending longitudinally therethrough; a rod extending from a distal end of the controller through the lumen of the tube; a runner fixedly coupled to a distal end of the tube, and rotatably and slideably mounted to the rod, the runner defining a lumen extending longitudinally therethrough, wherein the rod extends through the lumen of the runner; at least one cutting blade radially expandable about a longitudinal axis of the apparatus between a radially collapsed position for delivering the apparatus to a mitral valve and a radially expanded position for incising a mitral valve leaflet, wherein a proximal end of each blade is coupled to the runner, and a distal end of each blade is coupled to a guidewire extending away from a distal end of the cutting section; a joint fixedly coupled to a distal section of the rod and to a proximal end of the guidewire and to the distal end of each blade, wherein the tube and/or the runner are rotatable about a longitudinal axis defined by the apparatus; wherein a rotatable movement of the tube and/or the runner about the longitudinal axis defined by the apparatus and/or a slideable movement of the tube and/or the runner relative to the joint moves the at least one cutting blade between the radially collapsed position and the radially expanded position, and wherein the distance between the proximal end and the distal end of the at least one cutting blade is greater in the radially collapsed position than in the radially expanded position. a controller comprising a handle having a knob; a cutting section comprising: a tube coupled to the handle of the controller, the tube defining a lumen extending longitudinally therethrough; a rod extending from a distal end of the controller through the lumen of the tube; a runner fixedly coupled to a distal end of the tube, and rotatably and slideably mounted to the rod, the runner defining a lumen extending longitudinally therethrough, wherein the rod extends through the lumen of the runner; at least one cutting blade radially expandable about a longitudinal axis of the apparatus between a radially collapsed position for delivering the apparatus to a mitral valve and a radially expanded position for incising a mitral valve leaflet, wherein a proximal end of each blade is coupled to the runner, and a distal end of each blade is coupled to a guidewire extending away from a distal end of the cutting section; a joint fixedly coupled to a distal section of the rod and to a proximal end of the guidewire and to the distal end of each blade, wherein the tube and/or the runner are rotatable about a longitudinal axis defined by the apparatus; wherein a rotatable movement of the tube and/or the runner about the longitudinal axis defined by the apparatus and/or a slideable movement of the tube and/or the runner relative to the joint moves the at least one cutting blade between the radially collapsed position and the radially expanded position, and wherein the distance between the proximal end and the distal end of the at least one cutting blade is greater in the radially collapsed position than in the radially expanded position. a tube coupled to the handle of the controller, the tube defining a lumen extending longitudinally therethrough; a rod extending from a distal end of the controller through the lumen of the tube; a runner fixedly coupled to a distal end of the tube, and rotatably and slideably mounted to the rod, the runner defining a lumen extending longitudinally therethrough, wherein the rod extends through the lumen of the runner; at least one cutting blade radially expandable about a longitudinal axis of the apparatus between a radially collapsed position for delivering the apparatus to a mitral valve and a radially expanded position for incising a mitral valve leaflet, wherein a proximal end of each blade is coupled to the runner, and a distal end of each blade is coupled to a guidewire extending away from a distal end of the cutting section; a joint fixedly coupled to a distal section of the rod and to a proximal end of the guidewire and to the distal end of each blade, wherein the tube and/or the runner are rotatable about a longitudinal axis defined by the apparatus; wherein a rotatable movement of the tube and/or the runner about the longitudinal axis defined by the apparatus and/or a slideable movement of the tube and/or the runner relative to the joint moves the at least one cutting blade between the radially collapsed position and the radially expanded position, and wherein the distance between the proximal end and the distal end of the at least one cutting blade is greater in the radially collapsed position than in the radially expanded position.