TY - JOUR A1 - Buchhorn, Reiner A1 - Baumann, Christoph A1 - Willaschek, Christian T1 - Pathophysiological mechanisms of bradycardia in patients with anorexia nervosa JF - Health Science Reports N2 - Background The purpose of this investigation was to examine heart rate variability (HRV), interbeat interval (IBI), and their interrelationship in healthy controls, bradycardic hyperpolarization‐activated cyclic nucleotide‐gated channel 4 (HCN4) mutation carriers, and patients with anorexia nervosa (AN). We tested the hypothesis that neural mechanisms cause bradycardia in patients with AN. Therefore, we assumed that saturation of the HRV/IBI relationship as a consequence of sustained parasympathetic control of the sinus node is exclusively detectable in patients with AN. Methods Patients with AN between the ages of 12 and 16 years admitted to our hospital due to malnutrition were grouped and included in the present investigation (N = 20). A matched‐pair group with healthy children and adolescents was created. Groups were matched for age and sex. A 24‐hour Holter electrocardiography (ECG) was performed in controls and patients. More specifically, all patients underwent two 24‐hour Holter ECG examinations (admission; refeeding treatment). Additionally, the IBI was recorded during the night in HCN4 mutation carriers (N = 4). HRV parameters were analyzed in 5‐minute sequences during the night and plotted against mean corresponding IBI length. HRV, IBI, and their interrelationship were examined using Spearman's rank correlation analyses, Mann‐Whitney U tests, and Wilcoxon signed‐rank tests. Results The relationship between IBI and HRV showed signs of saturation in patients with AN. Furthermore, signs of HRV saturation were present in two HCN4 mutation carriers. In contrast, signs of HRV saturation were not present in controls. Conclusions The existence of HRV saturation does not support the existence of parasympathetically mediated bradycardia. Nonneural mechanisms, such as HCN4 downregulation, may be responsible for bradycardia and HRV saturation in patients with AN. KW - adolescent KW - anorexia nervosa KW - autonomic nervous system KW - electrocardiography KW - heart rate Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-244724 VL - 4 IS - 3 ER - TY - JOUR A1 - Wiemer, Julian A1 - Rauner, Milena M. A1 - Stegmann, Yannik A1 - Pauli, Paul T1 - Reappraising fear: is up-regulation more efficient than down-regulation? JF - Motivation and Emotion N2 - Catastrophizing thoughts may contribute to the development of anxiety, but functional emotion regulation may help to improve treatment. No study so far directly compared up- and down-regulation of fear by cognitive reappraisal. Here, healthy individuals took part in a cued fear experiment, in which multiple pictures of faces were paired twice with an unpleasant scream or presented as safety stimuli. Participants (N = 47) were asked (within-subjects) to down-regulate, to up-regulate and to maintain their natural emotional response. Valence and arousal ratings indicated successful up- and down-regulation of the emotional experience, while heart rate and pupil dilation increased during up-regulation, but showed no reduction in down-regulation. State and trait anxiety correlated with evaluations of safety but not threat stimuli, which supports the role of deficient safety learning in anxiety. Reappraisal did not modulate this effect. In conclusion, this study reveals evidence for up-regulation effects in fear, which might be even more efficient than down-regulation on a physiological level and highlights the importance of catastrophizing thoughts for the maintenance of fear and anxiety. KW - anxiety KW - fear conditioning KW - cognitive reappraisal KW - pupil diameter KW - heart rate Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-269187 SN - 1573-6644 VL - 45 IS - 2 ER -