Evaluating heart rate variability with 10†second multichannel electrocardiograms in a large population-based sample.

Introduction: Heart rate variability (HRV), defined as the variability of consecutive heart beats, is an important biomarker for dysregulations of the autonomic nervous system (ANS) and is associated with the development, course, and outcome of a variety of mental and physical health problems. While guidelines recommend using 5 min electrocardiograms (ECG), recent studies showed that 10 s might be sufficient for deriving vagal-mediated HRV. However, the validity and applicability of this approach for risk prediction in epidemiological studies is currently unclear to be used. Methods: This study evaluates vagal-mediated HRV with ultra-short HRV (usHRV) based on 10 s multichannel ECG recordings of N = 4,245 and N = 2,392 participants of the Study of Health in Pomerania (SHIP) from two waves of the SHIP-TREND cohort, additionally divided into a healthy and health-impaired subgroup. Association of usHRV with HRV derived from long-term ECG recordings (polysomnography: 5 min before falling asleep [N = 1,041]; orthostatic testing: 5 min of rest before probing an orthostatic reaction [N = 1,676]) and their validity with respect to demographic variables and depressive symptoms were investigated. Results: High correlations (r = .52-.75) were revealed between usHRV and HRV. While controlling for covariates, usHRV was the strongest predictor for HRV. Furthermore, the associations of usHRV and HRV with age, sex, obesity, and depressive symptoms were similar. Conclusion: This study provides evidence that usHRV derived from 10 s ECG might function as a proxy of vagal-mediated HRV with similar characteristics. This allows the investigation of ANS dysregulation with ECGs that are routinely performed in epidemiological studies to identify protective and risk factors for various mental and physical health problems.

Impact of Tablet Size and Shape on the Swallowability in Older Adults.

Older adults represent the major target population for oral medications, due to the high prevalence of multimorbidity. To allow for successful pharmacological treatments, patients need to adhere to their medication and, thus, patient-centric drug products with a high level of acceptability by the end users are needed. However, knowledge on the appropriate size and shape of solid oral dosage forms, as the most commonly used dosage forms in older adults, is still scarce. A randomized intervention study was performed including 52 older adults (65 to 94 years) and 52 young adults (19 to 36 years). Each participant swallowed four coated placebo tablets differing in weight (250 to 1000 mg) and shape (oval, round, oblong) in a blinded manner on three study days. The choice of tablet dimensions allowed for a systematic comparison between different tablet sizes of the same shape, as well as between different tablet shapes. Swallowability was assessed using a questionnaire-based method. All tested tablets were swallowed by ≥80% of adults, independent of age. However, only the 250 mg oval tablet was classified as well swallowable by ≥80% of old participants. The same was true for young participants; however, they also considered the 250 mg round and the 500 mg oval tablet as well swallowable. Furthermore, swallowability was seen to influence the willingness to take a tablet on a daily basis, especially for an intake over longer time periods.

Hold your breath: Voluntary breath-holding time predicts defensive activation to approaching internal threat.

Bodily disturbances, like dyspnea, elicit responses to regain homeostasis and ensure survival. However, this life-saving function can become hyperreactive, which may lead to the emergence of psychopathology. This study investigated whether maximal voluntary breath-holding time (mvBHT), a biobehavioral marker that characterizes sensitivity to respiratory stimulation, predicts defensive mobilization to cues signaling the proximity of a mild electric shock vs. a respiratory threat (shortness of breath elicited by forced breath-holding) and the opportunity to avoid threat delivery in 60 healthy participants. While the startle reflex, a measure of defensive mobilization, generally increased with the proximity of an inevitable threat, shorter breath-holding time was specifically associated with greater startle potentiation when anticipating a respiratory threat but not an electric shock. In contrast, when both threats were avoidable, the startle reflex was comparably inhibited, irrespective of mvBHT. This study suggests that mvBHT specifically predicts hypersensitive responding to an anticipated inevitable respiratory threat.

Predictors of behavioral avoidance during respiratory symptom provocation.

Excessive anxiety and avoidance during provocation of body symptoms are core features of anxiety-related disorders and might contribute to the development and maintenance of these disorders. Previous studies examined psychological (anxiety sensitivity, fear of suffocation and trait anxiety) and biobehavioral (breath-holding time) predictors of reported anxiety during symptom provocation. However, the role of these predictors on avoidance of feared body symptoms remains unclear. Therefore, the present work aimed at investigating the main and interactive effects of psychological and biobehavioral variables in predicting avoidance during provocation of dyspnea that successively increased in severity. 28 of 69 participants prematurely terminated the provocation sequence, thus preventing further progression of symptom provocation. Logistic regressions revealed that higher anxiety sensitivity and lower breath-holding time were significantly associated with avoidance during exposure. Suffocation fear and trait anxiety were not related to avoidance. Moreover, there was a significant interaction between breath-holding time and anxiety sensitivity in predicting avoidance. Participants with a lower breath-holding time showed more avoidance behavior when reporting high as compared to low anxiety sensitivity. The data suggest that anxiety sensitivity and breath-holding time increase the risk to show avoidance and thus might contribute to the development and maintenance of anxiety-related disorders.

Dynamics of Defensive Response Mobilization to Approaching External Versus Interoceptive Threat.

BACKGROUND: Excessive fear and anxiety are core features of anxiety disorders. Defensive response mobilization varies dynamically with threat proximity. METHODS: We analyzed defensive responses in 48 healthy students to an approaching external, predator-like threat (an electric shock resembling a predator attack) versus an approaching threat from inside the body (feeling of dyspnea as evoked by forced breath-holding). Threats either were inevitable or could be avoided by button press. RESULTS: Autonomic changes (heart rate, skin conductance), defensive reflex priming (startle eyeblink response), respiratory responses, and event-related potentials were assessed. Regardless of its source, when an approaching threat was inevitable, a defensive pattern emerged characterized by an increase in skin conductance, a potentiation of the startle reflex, and bradycardia. Minute ventilation increased only with approaching dyspnea. In preparation for active avoidance of either threat, startle magnitudes were inhibited and probe-elicited P3 wave amplitudes were reduced. Moreover, generation of avoidant action resulted in heart rate acceleration. CONCLUSIONS: This study demonstrates common and specific defensive activation patterns for approaching external and respiratory threats. The specific modulation in respiration in response to an inevitable respiratory threat may have important implications for our understanding of the etiology of anxiety disorders, especially panic disorder.

Dynamics of defensive response mobilization during repeated terminations of exposure to increasing interoceptive threat.

Resistant avoidance behaviors play a crucial role in the maintenance of anxiety disorders and are therefore central targets of therapeutic interventions. In the present study, the development of avoidance behavior was investigated in 24 healthy participants who repeatedly prematurely terminated the exposure to increasing interoceptive threat, i.e., the feeling of dyspnea induced by increasing inspiratory resistive loads that were followed by the ultimate threat, a short breathing occlusion. Physiological responses and subjective anxiety preceding terminations were compared to matched intervals of a matched control group (N=24) who completed the exposure. Initially, participants terminated during the ultimate threat, i.e., during occlusion. This first termination was preceded by a strong surge in autonomic arousal and reported anxiety. Startle reflex and the P3 component of event-related brain potentials to startle probes were strongly inhibited, indicating preparation for defensive action. With repetitive terminations, individuals successively terminated earlier, avoiding exposure to the occlusion. This avoidant behavior was accompanied by alleviated autonomic arousal as compared to the first termination. In addition, no indication of physiological response preparation was found implying that the avoidance behavior was performed in a rather habitual way. Matched controls did not show any indication of a defensive response surge in the matched intervals. In matched controls, no changes in physiological response patterns were detected while anxiety levels increased with repetitions. The present results shed new light on our understanding of the motivational basis of avoidance behavior and may help to refine etiological models, behavioral analysis and therapeutic strategies in treating anxiety disorders.