Effects of threat context and cardiac sensitivity on fear responding to a 35% CO2 challenge: A test of the context-sensitivity panic vulnerability model

Abstract The present study tested several predictions of a context-sensitivity panic vulnerability model emphasizing the interaction between threat context and threat sensitivities. Participants without a history of panic ( N  = 47) completed both global and domain-specific panic relevant sensitivity measures and were then randomized to undergo a 35% CO 2 inhalation challenge in the presence or absence of a cardiac defibrillator (threat context). As predicted by the model, cardiac sensitivity (but not trait anxiety or anxiety sensitivity) potentiated the effects of the presence of the defibrillator on CO 2 fear responding. Moreover, as predicted by the model, the observed potentiation effects of cardiac sensitivity on CO 2 fear responding were mediated by participants’ threat appraisals connected to the presence of the defibrillator. Theoretical and clinical implications are discussed.