An intravascular catheter system (10; 510) for use in a cryoablation procedure for treating a condition in a body, the intravascular catheter system comprising: a catheter shaft (228A; 528) having a shaft distal end that is configured to be selectively positioned within the body; a first inflatable balloon (230A; 232A; 568) positioned near the distal end of the catheter shaft (228A; 528), the first inflatable balloon (230A; 232A; 568) being configured to move between an inflated state and a substantially deflated state, the first inflatable balloon (230A; 232A; 568) having a maximum circumference in the inflated state; a plurality of electrodes that are attached to the first inflatable balloon (230A; 232A; 568), the plurality of electrodes configured to sense a physiological parameter within the body, the plurality of electrodes being positioned away from the maximum circumference of the first inflatable balloon (230A; 232A; 568) so that none of the electrodes are positioned on the maximum circumference of the first inflatable balloon (230A; 232A; 568); and a plurality of flex circuits secured to the first inflatable balloon (230A; 232A; 568), wherein the electrodes are coupled to the first inflatable balloon (230A; 232A; 568) via the plurality of flex circuits, and wherein at least two electrodes are positioned on each of the flex circuits, and wherein each of the flex circuits is positioned distal to the maximum circumference the first inflatable balloon (230A; 232A; 568); a controller and a plurality of conductors, each conductor carrying an electrical signal between at least one of the electrodes and the controller, the electrical signal being based on the physiological parameter; and a guidewire lumen and a guidewire that is positioned at least partially within the guidewire lumen, wherein the first inflatable balloon (230A; 232A; 568) is attached to the guidewire lumen, wherein the guidewire lumen has a lumen distal end, and wherein each conductor is routed from at least one of the electrodes to the controller via the lumen distal end of the guidewire lumen. a catheter shaft (228A; 528) having a shaft distal end that is configured to be selectively positioned within the body; a first inflatable balloon (230A; 232A; 568) positioned near the distal end of the catheter shaft (228A; 528), the first inflatable balloon (230A; 232A; 568) being configured to move between an inflated state and a substantially deflated state, the first inflatable balloon (230A; 232A; 568) having a maximum circumference in the inflated state; a plurality of electrodes that are attached to the first inflatable balloon (230A; 232A; 568), the plurality of electrodes configured to sense a physiological parameter within the body, the plurality of electrodes being positioned away from the maximum circumference of the first inflatable balloon (230A; 232A; 568) so that none of the electrodes are positioned on the maximum circumference of the first inflatable balloon (230A; 232A; 568); and a plurality of flex circuits secured to the first inflatable balloon (230A; 232A; 568), wherein the electrodes are coupled to the first inflatable balloon (230A; 232A; 568) via the plurality of flex circuits, and wherein at least two electrodes are positioned on each of the flex circuits, and wherein each of the flex circuits is positioned distal to the maximum circumference the first inflatable balloon (230A; 232A; 568); a controller and a plurality of conductors, each conductor carrying an electrical signal between at least one of the electrodes and the controller, the electrical signal being based on the physiological parameter; and a guidewire lumen and a guidewire that is positioned at least partially within the guidewire lumen, wherein the first inflatable balloon (230A; 232A; 568) is attached to the guidewire lumen, wherein the guidewire lumen has a lumen distal end, and wherein each conductor is routed from at least one of the electrodes to the controller via the lumen distal end of the guidewire lumen.