Search

Doppler ultrasound can be used to evaluate leg blood flow (Q̇leg), especially of interest when investigating peripheral vascular limitations in patients with chronic obstructive pulmonary disease (COPD). However, the within‐session repeatability, a subdomain of test‐retest reliability, of this method remains unknown. This study aimed to provide within‐session repeatability estimates of Doppler ultrasound‐based Q̇leg at rest and during single‐leg knee‐extensor exercise (KEE) in patients with COPD, and to compare these estimates to matched healthy controls. In this case‐controlled study, 16 participants with COPD were matched based on sex and age with 16 healthy controls. All participants underwent measurement of Q̇leg using Doppler ultrasound in a KEE setup at various intensities with the same measurement being performed again separated by 10 s. Smallest real difference (SRD) was lowest at rest in both groups and increased during exercise, reaching values ranging from 164 to 231 mL in COPD and 122–180 mL in the control group. The coefficient of variance (CV) was highest at rest and decreased during exercise to values ranging from 4.0% to 5.0% in COPD and 2.6%–3.2% in the control group. The CV was significantly lower in the control group during 0 watt and exercise at 20% of max watt, but apart from that, no reliability estimates were different between groups. To conclude, Doppler ultrasound showed nearly equal within‐session repeatability when evaluating Q̇leg in COPD patients and healthy individuals with a CV not exceeding 5% during exercise for both groups. [ABSTRACT FROM AUTHOR]

Highlights Doppler ultrasound may be used to assess leg blood flow (Q̇leg${{\dot{Q}}_{{\mathrm{leg}}}}$), but the reliability of this method remains unexplored in patients with chronic obstructive pulmonary disease (COPD), where between‐subject variability may be larger than healthy due to peripheral vascular changes. This study aimed to investigate the reliability of Doppler ultrasound in quantifying Q̇leg${{\dot{Q}}_{{\mathrm{leg}}}}$ during single‐leg knee‐extensor exercise (KEE) in COPD patients compared with those obtained from healthy matched controls. In this case–control study, 16 participants with COPD were matched based on sex and age with 16 healthy controls. All participants underwent measurement of Q̇leg${{\dot{Q}}_{{\mathrm{leg}}}}$ using Doppler ultrasound in a KEE set‐up at various intensities on two separate visits. Confounding factors on Q̇leg${{\dot{Q}}_{{\mathrm{leg}}}}$ were controlled for, and the ultrasound scans were consistently performed by the same sonographer. During exercise, smallest real difference (SRD) ranged from 367 mL to 583 mL in COPD and 438 mL to 667 mL in the control group. The coefficient of variation (CV) ranged from 7.9% to 14.3% in COPD and 9.4% to 10.4% in the control group. The intraclass correlation coefficient ranged from 0.75 to 0.92 in COPD and 0.67 to 0.84 in the control group. CV was lower in the control group during exercise at 0 W, but apart from that, reliability was not different between groups during exercise. Doppler ultrasound showed nearly equal reliability when evaluating Q̇leg${{\dot{Q}}_{{\mathrm{leg}}}}$ in COPD patients and healthy individuals with a CV below 15% during exercise for both groups. What is the central question of this study? What is the between‐day reliability of Doppler ultrasound when quantifying leg blood flow during single‐leg knee‐extensor exercise in COPD patients compared to healthy matched controls? What is the main finding and its importance? This study demonstrates a coefficient of variation ranging from 7.9 to 14.3% during single‐leg knee‐extensor exercise for between‐day reliability when applying Doppler ultrasound to assess leg blood flow in patients with COPD. Furthermore, it offers insights into the peripheral circulatory constraints in COPD, as evidenced by diminished leg blood flow. This study is the first of its kind to evaluate the reliability of Doppler ultrasound in the assessment of the peripheral circulation during exercise in COPD. What is the central question of this study?What is the between‐day reliability of Doppler ultrasound when quantifying leg blood flow during single‐leg knee‐extensor exercise in COPD patients compared to healthy matched controls?What is the main finding and its importance?This study demonstrates a coefficient of variation ranging from 7.9 to 14.3% during single‐leg knee‐extensor exercise for between‐day reliability when applying Doppler ultrasound to assess leg blood flow in patients with COPD. Furthermore, it offers insights into the peripheral circulatory constraints in COPD, as evidenced by diminished leg blood flow. This study is the first of its kind to evaluate the reliability of Doppler ultrasound in the assessment of the peripheral circulation during exercise in COPD. [ABSTRACT FROM AUTHOR]

A basic understanding of acid-base physiology is critical for the correct assessment of arterial blood gases in the clinical setting. In this context, collaborative teaching strategies in the undergraduate classroom setting may be useful, since it has been reported to enhance both transfer and retention of learned material in a time-efficient fashion. In a previous study, the authors found that conventional group work and peer instruction equally enabled second-year medical students to diagnose common acid-base disorders immediately after class, indicating successful transfer of the learned material. This article describes a 2-yr followup study in which they investigated whether these collaborative strategies also lead to long-term retention of the learned skills.

Background: Substantial data support a heritable basis for supraventricular tachycardias, but the genetic determinants and molecular mechanisms of these arrhythmias are poorly understood. We sought to identify genetic loci associated with atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular accessory pathways or atrioventricular reciprocating tachycardia (AVAPs/AVRT)., Methods: We performed multiancestry meta-analyses of genome-wide association studies to identify genetic loci for AVNRT (4 studies) and AVAP/AVRT (7 studies). We assessed evidence supporting the potential causal effects of candidate genes by analyzing relations between associated variants and cardiac gene expression, performing transcriptome-wide analyses, and examining prior genome-wide association studies., Results: Analyses comprised 2384 AVNRT cases and 106 489 referents, and 2811 AVAP/AVRT cases and 1,483 093 referents. We identified 2 significant loci for AVNRT, which implicate NKX2-5 and TTN as disease susceptibility genes. A transcriptome-wide association analysis supported an association between reduced predicted cardiac expression of NKX2-5 and AVNRT. We identified 3 significant loci for AVAP/AVRT, which implicate SCN5A , SCN10A , and TTN/CCDC141 . Variant associations at several loci have been previously reported for cardiac phenotypes, including atrial fibrillation, stroke, Brugada syndrome, and electrocardiographic intervals., Conclusions: Our findings highlight gene regions associated with ion channel function (AVAP/AVRT), as well as cardiac development and the sarcomere (AVAP/AVRT and AVNRT) as important potential effectors of supraventricular tachycardia susceptibility., Competing Interests: Disclosures Dr Lubitz is a full-time employee of Novartis as of July 2022. Previously, Dr Lubitz received research support from Bristol Myers Squibb/Pfizer, Bayer AG, Boehringer Ingelheim, Fitbit, IBM, Medtronic, and Premier, Inc, and consulted for Bristol Myers Squibb/Pfizer, Bayer AG, Blackstone Life Sciences, and Invitae. Dr Ellinor receives research support from Bayer AG, IBM, and Bristol Myers Squibb/Pfizer and has consulted for Novartis, MyoKardia, and Bayer AG. Dr Damrauer receives research support for RenalytixAI and has consulted for Calico Labs. Dr Svendsen is a member of Medtronic advisory boards and has received speaker honoraria and research grants from Medtronic outside this work. Dr Cutler has consulted for Janssen Scientific. Dr Roselli is supported by a grant from Bayer AG to the Broad Institute focused on the development of therapeutics for cardiovascular disease. The other authors report no conflicts.

We conducted a randomized, single-blinded study of the effect of alcohol intake during a hangover. We measured cardiovascular parameters, and the participants filled out a series of questionnaires regarding their well-being. We found, that an intake of five beers led to a significant decrease in systolic blood pressure, heart rate and self-reported feeling of palpitations. However, the self-reported sense of well-being did not improve. In addition, we found that the risk of brain freeze increased, as the beer's temperature fell.