Definition, detection and differentiation of acute emotional states using heart rate recording

Introduction Anxiety and panic disorders are psychiatric disorders characterized by the occurrence of acute states, represented by short-term emotional, behavioral and cardiac responses. Dysregulation of the autonomic nervous system plays an important role in the pathogenesis of a majority of psychiatric disorders, including anxiety and panic disorders, and recording of Heart rate variability (HRV) is widely accepted as a peripheral measure for autonomic activity. Although heart rate analysis has been employed in clinical studies as a biomarker for diagnosis and therapy outcome for a multitude of diseases, there has been no reliable correlation between acute emotional and cardiac states in behavioral contexts to this date. This study investigates how heart rate variability can be used to define, detect and differentiate acute emotional states in a moment-to-moment resolution.

Methods For correlative analysis of acute cardiac and emotional states, 140 healthy participants and 30 participants with a confirmed anxiety diagnosis between the ages of 6 and 18 years were exposed to an established fear conditioning and generalization paradigm. In parallel, heart rate was recorded by electrocardiography during fear conditioning and generalization. Analysis of heart rate variability was performed in temporal correlation to the events of the behavioral paradigm in order to characterize acute states.

Results We were able to detect and define acute emotional states during a behavioral paradigm in children and adolescents. In the group of 140 healthy participants, largely similar situation-dependent cardiac dynamics were observed during the execution of a fear conditioning and generalization paradigm. In the group of 30 participants with a confirmed anxiety diagnosis, however, a significantly higher inter-individual variability in the anticipatory and reactive heart rate was observed. In addition, cardiac response of anxious and healthy participants could be categorized into distinct subgroups.

Conclusion Presented results indicate detectable patterns in the cardiac processing of acute emotional states induced by a fear conditioning and generalization paradigm. Different heart rate responses in healthy and anxious participants suggest the use of correlative heart rate analysis in detection and diagnosis of psychiatric diseases associated with acute emotional states. In summary, this suggests further investigation of moment-to-moment heart rate analysis for the detection and differentiation of acute emotional states for a variety of psychiatric disorders.