A system, comprising: a cardiac pulse generator configured to generate cardiac paces to pace the heart; a sensor configured to sense a physiological signal for use in detecting pace-induced phrenic nerve stimulation, wherein the pace-induced phrenic nerve stimulation is phrenic nerve stimulation induced by electrical cardiac pace signals; a phrenic nerve stimulation detector configured to analyze the sensed physiological signal to detect PS beats, wherein the PS beats are cardiac paces that induce phrenic nerve stimulation; a controller configured to test for phrenic nerve stimulation threshold, wherein the controller is configured to: control the cardiac pulse generator to deliver cardiac paces at a pacing output level; use the phrenic nerve stimulation detector to detect if the pacing output level causes PS beats; analyze the detected PS beats, if PS beats are detected at the pacing output level, using criteria to determine if the pacing output level can be declared to be the PS threshold; and perform a PS beat confirmation procedure, if the pacing output level cannot be declared to be the PS threshold based on the analysis of the PS beat at the pacing output level, that includes delivering additional cardiac paces at the pacing output level to generate additional PS beats, and analyzing the detected PS beats using other criteria to determine if the pacing output level can be confirmed as the PS threshold. a cardiac pulse generator configured to generate cardiac paces to pace the heart; a sensor configured to sense a physiological signal for use in detecting pace-induced phrenic nerve stimulation, wherein the pace-induced phrenic nerve stimulation is phrenic nerve stimulation induced by electrical cardiac pace signals; a phrenic nerve stimulation detector configured to analyze the sensed physiological signal to detect PS beats, wherein the PS beats are cardiac paces that induce phrenic nerve stimulation; a controller configured to test for phrenic nerve stimulation threshold, wherein the controller is configured to: control the cardiac pulse generator to deliver cardiac paces at a pacing output level; use the phrenic nerve stimulation detector to detect if the pacing output level causes PS beats; analyze the detected PS beats, if PS beats are detected at the pacing output level, using criteria to determine if the pacing output level can be declared to be the PS threshold; and perform a PS beat confirmation procedure, if the pacing output level cannot be declared to be the PS threshold based on the analysis of the PS beat at the pacing output level, that includes delivering additional cardiac paces at the pacing output level to generate additional PS beats, and analyzing the detected PS beats using other criteria to determine if the pacing output level can be confirmed as the PS threshold. control the cardiac pulse generator to deliver cardiac paces at a pacing output level; use the phrenic nerve stimulation detector to detect if the pacing output level causes PS beats; analyze the detected PS beats, if PS beats are detected at the pacing output level, using criteria to determine if the pacing output level can be declared to be the PS threshold; and perform a PS beat confirmation procedure, if the pacing output level cannot be declared to be the PS threshold based on the analysis of the PS beat at the pacing output level, that includes delivering additional cardiac paces at the pacing output level to generate additional PS beats, and analyzing the detected PS beats using other criteria to determine if the pacing output level can be confirmed as the PS threshold.