1. A method of operating a cardiac device, comprising: delivering non-test pacing pulses to a heart in an automatic capture verification (ACV) mode during non-capture threshold test pacing therapy; determining if loss of capture occurs while pacing during the ACV mode; suspending the ACV mode if loss of capture occurs, otherwise maintaining the ACV mode; determining if a capture threshold was acquired within a predetermined amount of time prior to suspension of the ACV mode; if the capture threshold was acquired within the predetermined amount of time prior to the suspension of the ACV mode: initiating a safety pacing mode (SP) after suspension of the ACV mode; and delivering pacing pulses having a pacing energy that is based on the capture threshold energy during the SP mode; if the capture threshold was not acquired within the predetermined amount of time prior to suspension of the ACV mode: initiating the SP mode after suspension of the ACV mode; and delivering pacing pulses having a pacing energy of a predetermined energy during the SP mode; initiating a capture threshold test (CTT) mode during which primary pacing pulses and backup pacing pulses are delivered during cardiac cycles of the CTT mode; determining if the ACV mode is active or non active at the time the CCT mode is initiated; if the ACV mode is not active at the time the CCT mode is initiated, adjusting a pacing energy for backup pacing during the CTT mode based on the capture threshold energy used during the SP mode; and if the ACV mode is active at the time the CCT mode is initiated, adjusting the pacing energy for the backup pacing during the CTT mode to a predetermined energy.