A system is provided for performing injections in the ventricle of a patient. The system includes an injection catheter with a proximal and distal end. Importantly, a flexible array is mounted at the distal end of the injection catheter and is moveable between a protective configuration and a flared configuration. Also, a needle of variable length is mounted on the distal end of the injection catheter and is covered by the flexible array when the array is in its protective configuration. In order to manipulate the flexible array, a locking mechanism is mounted on the proximal end of the injection catheter for engagement with the flexible array. When selectively operated, the locking mechanism moves the array from its protective configuration to the flared configuration, holds the array in its flared configuration for an injection, and subsequently moves the array back to its protective configuration.