A splint assembly for placement transverse a heart chamber to reduce the heart chamber radius and improve cardiac function has a tension member formed of a braided cable with a covering. A fixed anchor assembly is attached to one end of the tension member and a leader for penetrating a heart wall and guiding the tension member through the heart is attached to the other end. An adjustable anchor assembly can be secured onto the tension member opposite to the side on which the fixed pad assembly is attached. The adjustable anchor assembly can be positioned along the tension member so as to adjust the length of the tension member extending between the fixed and adjustable anchor assemblies. The pad assemblies engage with the outside of the heart wall to hold the tension member in place transverse the heart chamber. A probe and marker delivery device is used to identify locations on the heart wall to place the splint assembly such that it will not interfere with internal heart structures. The device delivers a marker to these locations on the heart wall for both visual and tactile identification during implantation of the splint assembly in the heart.