Effects of explicit and implicit perseverative cognition on cardiac recovery after cognitive stress

Slow cardiovascular (CV) recovery after stress is a predictor of adverse CV outcomes. Perseverative cognition (PC) about stress has been hypothesized to co-determine slow recovery. In the present study, it was investigated whether two types of trait PC, i.e. trait worry and trait rumination, predicted delayed cardiac recovery after a cognitive stressor. Furthermore, it was examined whether explicit state PC (i.e. negative intrusive thoughts) or implicit state PC (i.e. automatic vigilance) additionally predicted delayed cardiac recovery. Fifty-nine participants performed a stressful task, which consisted of an unsolvable synonym task. After a 6-minute recovery period, participants reported on their level of negative intrusive thoughts (i.e. explicit state PC), and performed a lexical decision task (LDT) to measure automatic vigilance for task-related information (i.e. implicit state PC). Cardiac activity was continuously measured using heart rate (HR) and heart rate variability (HRV). Trait worry and rumination were measured by the Penn State Worry Questionnaire (PSWQ) and the Ruminative Response Scale (RRS), respectively. The results showed that high trait worriers had a slower HR recovery from the cognitive stressor compared to low trait worriers. They also showed delayed HRV recovery, but only when the tendency to dwell upon one's negative mood (the 'brooding' subscale of the RRS) was low. Slow HR recovery was associated with high levels of negative intrusive thoughts and with automatic vigilance, but in the unexpected direction for the latter. These results provide evidence that delayed cardiac recovery is associated with trait as well as state PC, and suggest that brooding attenuates the HRV suppressing effect of high trait worry.