Heart rate and heart rate variability in panic, social anxiety, obsessive-compulsive, and generalized anxiety disorders at baseline and in response to relaxation and hyperventilation.

It remains unclear if diminished high frequency heart rate variability (HF-HRV) can be found across anxiety disorders. HF-HRV and heart rate (HR) were examined in panic (PD), generalized anxiety (GAD), social anxiety (SAD), and obsessive-compulsive disorder (OCD) relative to healthy controls at baseline and during anxiety stressors. All disorders evidenced diminished baseline HF-HRV relative to controls. Baseline HRV differences were maintained throughout relaxation. For hyperventilation, PD and GAD demonstrated greater HR than controls. Psychotropic medication did not account for HF-HRV differences except in OCD. Age and sex evidenced multiple main effects. Findings suggest that low baseline HF-HRV represents a common index for inhibitory deficits across PD, GAD, and SAD, which is consistent with the notion of autonomic inflexibility in anxiety disorders. Elevated HR responses to hyperventilation, however, are specific to PD and GAD.

Feedback of end-tidal pCO2 as a therapeutic approach for panic disorder.

BACKGROUND: Given growing evidence that respiratory dysregulation is a central feature of panic disorder (PD) interventions for panic that specifically target respiratory functions could prove clinically useful and scientifically informative. We tested the effectiveness of a new, brief, capnometry-assisted breathing therapy (BRT) on clinical and respiratory measures in PD. METHODS: Thirty-seven participants with PD with or without agoraphobia were randomly assigned to BRT or to a delayed-treatment control group. Clinical status, respiration rate, and end-tidal pCO(2) were assessed at baseline, post-treatment, 2-month and 12-month follow-up. Respiratory measures were also assessed during homework exercises using a portable capnometer as a feedback device. RESULTS: Significant improvements (in PD severity, agoraphobic avoidance, anxiety sensitivity, disability, and respiratory measures) were seen in treated, but not untreated patients, with moderate to large effect sizes. Improvements were maintained at follow-up. Treatment compliance was high for session attendance and homework exercises; dropouts were few. CONCLUSIONS: The data provide preliminary evidence that raising end-tidal pCO(2) by means of capnometry feedback is therapeutically beneficial for panic patients. Replication and extension will be needed to verify this new treatment's efficacy and determine its mechanisms.

Hyperventilation in the vestibular clinic: use of the Nijmegen Questionnaire.

The objective of the present study was to determine the prevalence of hyperventilation syndrome in patients seen for vestibular assessment and to assess the clinical utility of the Nijmegen Questionnaire in this group. The Nijmegen Questionnaire and Dizziness Handicap Inventory (DHI) were administered prospectively to a consecutive series of 100 patients identified as candidates for vestibular assessment within the University Hospital Neuro-otology practice. Twenty-three per cent of patients seen for vestibular assessment were diagnosed with hyperventilation syndrome using the Nijmegen Questionnaire. Seventeen of these (74%) would have remained undetected had the Nijmegen questionnaire not been used. No relationship was found between vestibular assessment results and either Nijmegen or DHI scores. A significant correlation was found between DHI scores and Nijmegen Questionnaire scores (rho = 0.348, P = 0.0005). In conclusion, the Nijmegen Questionnaire is a quick, easy to administer and low-impact assessment tool for hyperventilation syndrome and is a useful adjunct to the otological consultation. Diagnosed patients can then be offered breathing control exercises as part of a vestibular rehabilitation programme.

[Medical accidents in the dental practice. Survey of 471 dentists in the Netherlands]. / Medische accidenten in de tandartspraktijk. Rapportage door 471 tandartsen in Nederland.

OBJECTIVE: To determine frequency and nature of medical accidents in Dutch dental practice in relation to type and time of treatment, with and without the use of the MRRH; frequency and nature of the professional assistance. METHOD: Dentists MRRH-users (n = 51) and control dentists (n = 420) recorded medical accidents by name, using a registration form, followed by an anonymous survey. RESULTS: 91 accidents were reported by name by 471 dentists. This contrasted with 300 accidents recorded by 380 dentists in an anonymous survey. No life threatening accidents were reported. Syncope and hyperventilation were frequent. Most of the accidents occurred during local anaesthesia or during treatment, as the procedure became more stressful. Two-third of the accidents could possibly have been prevented by means of a medical history. Medical assistance was requested in 6% of the cases. CONCLUSION: Life threatening disorders were not reported, possible because in the Netherlands no intravenous sedation or general anaesthetic is used in general dental practice.