Safe in my heart: resting heart rate variability longitudinally predicts emotion regulation, worry and sense of safeness during COVID-19 lockdown

Due to its ability to reflect the capacity to engage in context-appropriate responses, tonic heart rate variability (HRV) is considered a putative biomarker of stress resilience. However, most studies are cross-sectional, precluding causal inferences. The high levels of uncertainty and fear at a global level that characterize the COVID-19 pandemic offer a unique opportunity to investigate the longitudinal role of HRV in stress resilience. The present study examined whether HRV, measured about 2 years earlier (Time 0), could predict emotion regulation strategies and daily affect in healthy adults during the May 2020 lockdown (Time 1). Moreover, we evaluated the association between HRV measures, emotion regulation strategies, subjective perception of COVID-19 risk, and self-reported depressive symptoms at Time 1. Higher tonic HRV at Time 0 resulted a significant predictor of a stronger engagement in more functional emotion regulation strategies, as well as of higher daily feelings of safeness and reduced daily worry at Time 1. Moreover, depressive symptoms negatively correlated with HRV and positively correlated with the subjective perception of COVID-19 risk at Time 1. Current data support the view that HRV might be not only a marker but also a precursor of resilience under stressful times.