Rapid, Large, and Synchronous Sweat and Cardiovascular Responses Upon Minor Stimuli in Healthy Subjects. Dynamics and Reproducibility

Purpose: The aim of the study was to investigate steady state levels, dynamics and reproducibility of cardiovascular variables and electrodermal activity in different skin areas in response to minor physiological and mental stimuli in healthy subjects in the thermoneutral zone, carried out in high time resolution. Methods: Thirteen healthy subjects underwent experiments on two separate days. Non-invasive electrodermal activity in five different skin areas was measured continuously using a skin conductance method, including resting supine and sitting positions, performing deep inspirations, a mental challenge and being exposed to a sudden loud sound. Blood pressure, heart rate, radial artery blood flow, and skin perfusion were measured simultaneously. Results: Electrodermal activity in the right and left palms was almost identical, with rapid and large increases within a few seconds in response to stimuli, whereas no such significant changes were seen in the face, back, and abdomen. Radial artery blood flow and palmar skin perfusion changed synchronously with electrodermal activity for each stimulus, and were correlated to changes in blood pressure and heart rate. The response patterns in each subject were very similar on the two experimental days. There was very low spontaneous electrodermal activity in the supine position, contrary to the resting sitting position. Conclusion: The electrodermal activity increased rapidly and synchronously in both palms within a few seconds as a response to minor physiological and mental stimuli, synchronous with fluctuations in radial artery blood flow, palmar skin perfusion, and cardiovascular variables. The responses are reproducible from day to day, making them a stable and constant stimuli to be used for studies in patients with hyperhidrosis

Self-reported health status and disease-specific quality of life one year after treatment for peripheral arterial disease in clinical practice

Background VascuQoL-6 (VQ-6) is a disease-specific quality of life (QoL) instrument validated for use in clinical practice and vascular registries before and after treatment for peripheral arterial disease (PAD). To improve future interpretation of self-reported outcome, an unselected cohort was followed through one year to provide observational data after both conservative and invasive treatment. Methods Consecutive patients with intermittent claudication (IC) or critical limb ischemia (CLI) were included. All patients completed VQ-6 and Short Form-36 (SF-36), and were evaluated with ankle-brachial index (ABI) measurement pre- and post-exercise, a constant load treadmill test and clinical consultation at baseline and after one year. Change statistics and correlation analysis were used to describe self-reported outcome after conservative and invasive treatment for PAD. Results One hundred seventy-one patients with peripheral arterial disease (PAD) were included, 70 (41%) female. 147 (86%) of the patients suffered from IC. 136 (80%) patients had one-year follow up, death, amputation and withdrawal were the major causes of loss to follow-up. Forty-eight patients (35%) evaluated their health to be unchanged compared to one year ago. There was a strong correlation between self-reported general health status based on SF-36 item 2 and VQ-6 summary score (Spearmans rho = − 0.536). Patients admitted to invasive intervention (endovascular or surgery) improved in all domains of SF-36, and in the physical component summary score (SF-36 PCS). Patients admitted to best medical treatment, smoking cessation and walking exercise (conservative group) improved only in the physical domains. There was significant improvement in VQ-6 summary score for both groups, mean 2.20 (95%CI 1.14–3.27) in the conservative group, 4.68 (95%CI 3.67–5.70) in the invasive group. VQ-6 sum score improved more than four points for 56% in the invasive group, 36% in the conservative group. Conclusions Treatment for symptomatic PAD, both invasive and conservative, improves self-reported health status and disease specific QoL after one year. Interpretation of patient-reported outcome measured with VQ-6 after surgery or endovascular treatment must be seen in light of the improvement from conservative treatment alone. Trial registration ISRCTN14846962 (retrospectively registered)

Validation of the Vascular quality of life questionnaire – 6 for clinical use in patients with lower limb peripheral arterial disease

Background The VascuQoL-6 (VQ-6) health-related quality of life questionnaire, a short version of the disease-specific VascuQoL-25, was developed for clinical practice and use in vascular registries. The study purpose was to evaluate the validity and reliability of VQ-6. Methods VQ-6 was translated to Norwegian with linguistic validation and face value evaluation, and consecutive patients with intermittent claudication (IC) or critical limb ischemia (CLI) were included. All patients completed VQ-6 and Short Form-36 (SF-36), and were evaluated with ankle-brachial index (ABI) measurement pre- and post-exercise, a constant load treadmill test and clinical consultation at baseline and after 4 weeks. Correlation analysis, change statistics and receiver operator characteristics (ROC) curves were used to evaluate reliability, validity and responsiveness to change. Results One hundred seventy-one patients with peripheral arterial disease (PAD) were included, 70 (41%) female. 147 (86%) of the patients suffered from IC. The reliability of VQ-6 was good, Cronbachs-α 0.82. The ability of VQ-6 to differentiate between IC and CLI was good, area under the curve (AUC) 0.754. There was good correlation between SF-36 physical domains and component scores and VQ-6 score (r = 0.55–0.62) and excellent responsiveness to change after treatment, standard response mean (SRM) 1.12. The clinical anchors of ABI at rest, treadmill walking performance and Fontaine class improvement were less responsive to change than VQ-6, SF-36 and the vascular surgeon’s evaluation. Conclusions VQ-6 is reliable and valid, and can be used to evaluate PAD treatment in clinical practice and in vascular registries. Further research is necessary to determine the clinically important change over time. Trial registration ISRCTN14846962 (retrospectively registered)