Comparison of anterior mitral line and mitral isthmus line for ablation of mitral annular flutter.

BACKGROUND: Mitral annular flutter (MAF) is the most common left atrial macro-reentrant arrhythmia following catheter ablation of atrial fibrillation (AF). The best ablation approach for this arrhythmia remains unclear. METHODS: This single-center, retrospective study sought to compare the acute and long-term outcomes of patients with MAF treated with an anterior mitral line (AML) versus a mitral isthmus line (MIL). Acute ablation success, complication rates, and long-term arrhythmia recurrence were compared between the two groups. RESULTS: Between 2015 and 2021, a total of 81 patients underwent ablation of MAF (58 with an AML and 23 with a MIL). Acute procedural success defined as bidirectional block was achieved in 88% of the AML and 91% of the MIL patients respectively (p = 1.0). One year freedom from atrial arrhythmias was 49.5% versus 77.5% and at 4 years was 24% versus 59.6% for AML versus MIL, respectively (hazard ratio [HR]: 0.38, confidence interval [CI]: 0.17-0.82, p = .009). Fewer patients in the MIL group had recurrent atrial flutter when compared to the AML group (HR: 0.32, CI: 0.12-0.83, p = .009). The incidence of recurrent AF, on the other side, was not different between both groups (21.7% vs. 18.9%; p = .76). There were no serious adverse events in either group. CONCLUSION: In this retrospective study of patients with MAF, a MIL compared to AML was associated with a long-term reduction in recurrent atrial arrhythmias driven by a reduction in macroreentrant atrial flutters.

Microbial Diversity Impacts Non-Protein Amino Acid Production in Cyanobacterial Bloom Cultures Collected from Lake Winnipeg.

Lake Winnipeg in Manitoba, Canada is heavily impacted by harmful algal blooms that contain non-protein amino acids (NPAAs) produced by cyanobacteria: N-(2-aminoethyl)glycine (AEG), ß-aminomethyl-L-alanine (BAMA), ß-N-methylamino-L-alanine (BMAA), and 2,4-diaminobutyric acid (DAB). Our objective was to investigate the impact of microbial diversity on NPAA production by cyanobacteria using semi-purified crude cyanobacterial cultures established from field samples collected by the Lake Winnipeg Research Consortium between 2016 and 2021. NPAAs were detected and quantified by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) using validated analytical methods, while Shannon and Simpson alpha diversity scores were determined from 16S rRNA metagenomic sequences. Alpha diversity in isolate cultures was significantly decreased compared to crude cyanobacterial cultures (p < 0.001), indicating successful semi-purification. BMAA and AEG concentrations were higher in crude compared to isolate cultures (p < 0.0001), and AEG concentrations were correlated to the alpha diversity in cultures (r = 0.554; p < 0.0001). BAMA concentrations were increased in isolate cultures (p < 0.05), while DAB concentrations were similar in crude and isolate cultures. These results demonstrate that microbial community complexity impacts NPAA production by cyanobacteria and related organisms.

Symptom Reduction and Engagement in a Cognitive-Behavioral Mobile Phone App: A Study of User Profiling to Determine Prognostic Indicators.

OBJECTIVE: We investigated the presence of latent transition profiles in a sample of users of a cognitive-behavioral mental health app for the general population. Users' baseline characteristics were used as predictors of the profiles. The role of engagement with the app in the transition profiles was examined. METHOD: A total of 541 users completed the Patient Health Questionnaire-9 and the General Anxiety Disorder-7 when started using the app and 30 days after. Random-Intercept Latent Transition Analysis was implemented to identify users' profiles and transition patterns as classes. The age of the users and the Emotional Self-Awareness Scale-Revised (ESAS-R) were used as predictors of class membership at baseline. The Homework Rating Scale-Mobile Application (HRS-MA; as a measure of engagement) was used as a predictor of class membership at 30 days of app use. RESULTS: A 3-class solution was obtained according to the severity of symptoms (from mild to moderately severe). Age and ESAS-R predicted class membership initially; the higher the age and ESAS-R, the higher the probability of starting using the app with lower distress levels. The HRS-MA predicted class membership at 30 days of app use; the higher the engagement for more symptomatic and younger users, the higher the probability of improvement. However, older users tended to engage less. CONCLUSION: Our findings underpin the relevance of easily accessible digital interventions for young adults with mild to moderate mental health problems. Further studies and developments are required to enhance these apps for older cohorts.

Right atrial collision time (RACT): A novel marker of propensity for typical atrial flutter.

INTRODUCTION: The risk of typical atrial flutter (AFL) is increased proportionately to right atrial (RA) size or right atrial scarring that results in reduced conduction velocity. These characteristics result in propagation of a flutter wave by ensuring the macro re-entrant wave front does not meet its refractory tail. The time taken to traverse the circuit would take account of both of these characteristics and may provide a novel marker of propensity to develop AFL. Our goal was to investigate right atrial collision time (RACT) as a marker of existing typical AFL. METHODS: This single-centre, prospective study recruited consecutive typical AFL ablation patients that were in sinus rhythm. Controls were consecutive electrophysiology study patients >18 years of age. While pacing the coronary sinus (CS) ostium at 600 ms, a local activation time map was created to locate the latest collision point on the anterolateral right atrial wall. This RACT is a measure of conduction velocity and distance from CS to a collision point on the lateral right atrial wall. RESULTS: Ninety-eight patients were included in the analysis, 41 with atrial flutter and 57 controls. Patients with atrial flutter were older, 64.7 ± 9.7 versus 52.4 ± 16.8 years (<.001), and more often male (34/41 vs. 31/57 [.003]). The AFL group mean RACT (132.6 ± 17.3 ms) was significantly longer than that of controls (99.1 ± 11.6 ms) (p < .001). A RACT cut-off of 115.5 ms had a sensitivity and specificity of 92.7% and 93.0%, respectively for diagnosis of atrial flutter. A ROC curve indicated an AUC of 0.96 (95% CI: 0.93-1.0, p < .01). CONCLUSION: RACT is a novel and promising marker of propensity for typical AFL. This data will inform larger prospective studies.

A single strand: A simplified approach to DNA origami.

Just as a single polypeptide strand can self-fold into a complex 3D structure, a single strand of DNA can self-fold into DNA origami. Most DNA origami structures (i.e., the scaffold-staple and DNA tiling systems) utilize hundreds of short single-stranded DNA. As such, these structures come with challenges inherent to intermolecular construction. Many assembly challenges involving intermolecular interactions can be resolved if the origami structure is constructed from one DNA strand, where folding is not concentration dependent, the folded structure is more resistant to nuclease degradation, and the synthesis can be achieved at an industrial scale at a thousandth of the cost. This review discusses the design principles and considerations employed in single-stranded DNA origami and its potential benefits and drawbacks.

Half-Normal Saline vs Normal Saline for Cavotricuspid Isthmus-Dependent Atrial Flutter Ablation.

Background: Cavotricuspid isthmus (CTI) ablation requires permanent bidirectional block to prevent recurrence of typical atrial flutter (AFL). Catheter irrigation with half-normal saline (HNS) produces larger and deeper lesions in experimental models compared with normal saline (NS). This study was performed to compare the clinical efficacy and safety of HNS vs NS irrigation for typical AFL ablation. Methods: Sixty patients undergoing catheter ablation of typical AFL were randomized 1:1 to NS or HNS irrigation. Endpoints included time to CTI block, acute reconnection, incidence of steam pops, and recurrence of AFL during follow-up. Results: Baseline characteristics were comparable between both arms. The mean age of the patients was 68.5 ± 8.2 years, 20% were female, and 32% had atrial fibrillation before being enrolled. Bidirectional CTI block was obtained in all patients with no difference in time to CTI block between groups (6.4 ± 4.4 minutes vs 7.6 ± 4.5 minutes, respectively; P = 0.15). There was a trend to less acute reconnection in the HNS group compared with NS (13.3% vs 26.6%; P = 0.46). Steam pops occurred in 4 patients using HNS vs none in the NS group, but no major complications were observed. During the follow-up, rate of AFL recurrence was similar between groups (6.7% with HNS vs 10% with NS; P = 0.5). There was no difference in time to recurrence (7.6 ± 6.9 vs 4.9 ± 4.5 months; P = 0.6). Conclusions: In this small pilot randomized controlled trial, there was no significant difference between HNS and NS for CTI ablation; however, HNS may increase the incidence of steam pops.

Contexte: Pour prévenir la récurrence d'un flutter auriculaire (flutter) typique, l'ablation de l'isthme cavotricuspidien exige un bloc de conduction bidirectionnel permanent. Dans des modèles expérimentaux, l'irrigation par cathéter au moyen d'un soluté demi-salin produit des lésions plus larges et plus profondes, comparativement à un soluté physiologique salin. La présente étude a été réalisée dans le but de comparer l'efficacité clinique et l'innocuité de l'irrigation au moyen d'un soluté demi-salin à celles de l'irrigation par un soluté physiologique salin dans les cas d'ablation d'un flutter. Méthodologie: Soixante patients soumis à une ablation d'un flutter typique par cathéter ont été répartis au hasard dans un rapport de 1:1 en deux groupes d'irrigation, soit par soluté demi-salin, soit par soluté physiologique salin. Les critères d'évaluation de l'étude étaient les suivants : temps écoulé jusqu'au bloc de l'isthme cavotricuspidien, reconnexion aiguë, jet de vapeur sonore (steam pop) et récidive de flutter durant le suivi. Résultats: Les caractéristiques initiales étaient comparables dans les deux groupes. Les patients avaient une moyenne d'âge de 68,5 ± 8,2 ans, 20 % étaient des femmes et 32 % présentaient une fibrillation auriculaire avant leur admission à l'étude. Un bloc bidirectionnel dans l'isthme cavotricuspidien a été obtenu chez tous les patients, sans différence entre les groupes en ce qui a trait au temps écoulé jusqu'à l'obtention du bloc isthmique (6,4 ± 4,4 minutes vs 7,6 ± 4,5 minutes, respectivement; p = 0,15). Une tendance vers un nombre plus faible de cas de reconnexion aiguë a été notée dans le groupe d'irrigation par soluté demi-salin, comparativement au soluté physiologique salin (13,3 % vs 26,6 %; p = 0,46). Un jet de vapeur sonore est survenu chez 4 patients recevant un soluté demi-salin contre aucun dans le groupe sous soluté physiologique salin, mais aucune complication importante n'a été relevée. Durant le suivi, le taux de récidive de flutter a été similaire dans les deux groupes (6,7 % sous soluté demi-salin vs 10 % sous soluté physiologique salin; p = 0,5). Aucune différence n'a été notée pour ce qui est du temps écoulé jusqu'à la survenue d'une récidive (7,6 ± 6,9 vs 4,9 ± 4,5 mois; p = 0,6). Conclusions: Dans cette petite étude pilote contrôlée et avec répartition aléatoire, aucune différence significative n'a été observée entre le soluté demi-salin et le soluté physiologique salin pour l'ablation de l'isthme; toutefois, le soluté demi-salin augmenterait la fréquence des cas de jet de vapeur sonore.

Engagement with smartphone-delivered behavioural activation interventions: a study of the MoodMission smartphone application.

BACKGROUND: Despite increased research interest in smartphone mental health applications (MHapps), few studies have examined user engagement and its determinants. MoodMission is a MHapp that targets low mood and anxiety via evidence-based techniques including behavioural activation (BA). AIMS: The present study aimed to investigate (i) whether BA interventions delivered with visual psychoeducation had greater engagement than BA interventions delivered with solely written psychoeducation, (ii) whether BA interventions targeting mastery would have greater engagement than those targeting pleasure, and (iii) the relationship between level of engagement and MHapp benefit. METHOD: Participants downloaded MoodMission and completed activities and within-app evaluations over a 30-day period. Data from 238 MoodMission users were analysed via multi-level modelling and linear regression. RESULTS: The average number of app-based activities completed was 5.46 and the average self-reported engagement level was in the low to moderate range. As hypothesized, higher levels of engagement significantly predicted more positive activity appraisal. CONCLUSIONS: The results suggest that BA technique beliefs are involved in MHapp engagement and future research examining user appraisals of techniques is warranted.

Mental Health Consequences of Adversity in Australia: National Bushfires Associated With Increased Depressive Symptoms, While COVID-19 Pandemic Associated With Increased Symptoms of Anxiety.

High quality monitoring of mental health and well-being over an extended period is essential to understand how communities respond to the COVID-19 pandemic and how to best tailor interventions. Multiple community threats may also have cumulative impact on mental health, so examination across several contexts is important. The objective of this study is to report on changes in mental health and well-being in response to the Australian bushfires and COVID-19 pandemic. This study utilized an Experience-Sampling-Method (ESM), using the smartphone-based mood monitoring application, MoodPrism. Participants were prompted once a day to complete a brief survey inquiring about symptoms of depression and anxiety, and several well-being indices, including arousal, emotional valence, self-esteem, motivation, social connectedness, meaning and purpose, and control. Participants were N = 755 Australians (aged 13 years and above) who downloaded and used MoodPrism, between 2018 and 2020. Results showed that anxiety symptoms significantly increased during the COVID-19 pandemic, but not during the bushfires. This may be explained by concurrent feelings of social connectedness maintained during the bushfires but not during the pandemic. In contrast, depressive symptoms increased significantly during the bushfires, which maintained during the pandemic. Most indices of well-being decreased significantly during the bushfires, and further again during the pandemic. Study findings highlight the unique responses to the bushfire and COVID-19 crises, revealing specific areas of resilience and vulnerability. Such information can help inform the development of public health interventions or individual clinical treatment, to improve treatment approaches and preparedness for potential future community disasters.

Close-coupled pacing to identify the "functional" substrate of ventricular tachycardia: Long-term outcomes of the paced electrogram feature analysis technique.

BACKGROUND: The conduction delay and block that compose the critical isthmus of macroreentrant ventricular tachycardia (VT) is partly "functional" in that they only occur at faster cycle lengths. Close-coupled pacing stresses the myocardium's conduction capacity and may reveal late potentials (LPs) and fractionation. Interest has emerged in targeting this functional substrate. OBJECTIVE: The purpose of this study was to assess the feasibility and efficacy of a functional substrate VT ablation strategy. METHODS: Patients with scar-related VT undergoing their first ablation were recruited. A closely coupled extrastimulus (ventricular effective refractory period + 30 ms) was delivered at the right ventricular apex while mapping with a high-density catheter. Sites of functional impaired conduction exhibited increased electrogram duration due to LPs/fractionation. The time to last deflection was annotated on an electroanatomic map, readily identifying ablation targets. RESULTS: A total of 40 patients were recruited (34 [85%] ischemic). Median procedure duration was 330 minutes (interquartile range [IQR] 300-369), and ablation time was 49.4 minutes (IQR 33.8-48.3). Median functional substrate area was 41.9 cm2 (IQR 22.1-73.9). It was similarly distributed across bipolar voltage zones. Noninducibility was achieved in 34 of 40 patients (85%). Median follow-up was 711 days (IQR 255.5-972.8), during which 35 of 39 patients (89.7%) did not have VT recurrence, and 3 of 39 (7.5%) died. Antiarrhythmic drugs were continued in 53.8% (21/39). CONCLUSION: Functional substrate ablation resulted in high rates of noninducibility and freedom from VT. Mapping times were increased considerably. Our findings add to the encouraging trend reported by related techniques. Randomized multicenter trials are warranted to assess this next phase of VT ablation.

A randomized controlled trial of three smartphone apps for enhancing public mental health.

Many smartphone applications (apps) for mental health (MHapps) are available to the public. However, few have been the subject of a randomized controlled trial (RCT), and the change processes that are hypothesized to mediate claimed effects have not been previously studied. This RCT compared the efficacy of three publicly available MHapps to a waitlist control condition in a community sample, in which no MHapp was provided. The three MHapps included cognitive behavioural therapy (CBT) toolkit app MoodKit, mood tracking app MoodPrism, and CBT strategy app MoodMission. Participants were randomly allocated to each condition, completed a baseline assessment, downloaded their allocated MHapp, and completed a second assessment 30 days later, with n = 226 included in final analyses (81% female; M age = 34 years). Compared to the control condition, all MHapp groups experienced increases in mental wellbeing, MoodKit and MoodMission groups experienced decreases in depression, and no groups experienced effects on anxiety. Mediated regressions revealed that increasing coping self-efficacy, rather than emotional self-awareness or mental health literacy, was the underlying process contributing to effects on mental health for all three MHapps. MHapps appear to be an effective solution for improving public mental health, notably by improving users' confidence in their ability to cope.

Engagement in mobile phone app for self-monitoring of emotional wellbeing predicts changes in mental health: MoodPrism.

BACKGROUND: Mobile apps are being used increasingly for mental health purposes, but evidence of their efficacy remains limited. The mechanisms underlying any effects of such apps are also unclear. This study examined the effectiveness of a self-monitoring mobile phone app by investigating the relationships between app engagement and mental health outcomes. METHOD: Participants downloaded the MoodPrism app from the iOS and Android app stores, completing in-app assessments at start of use and again 30days later. The app prompted participants daily to complete a short mood questionnaire and formulated their responses into a mood diary. Data from 234 assessment completers (73% female; M age = 34.8 years) were analysed via hierarchical and mediation regressions. RESULTS: In this community sample, app engagement ratings predicted decreases in depression and anxiety, and increases in mental well-being. These effects were mediated by increases in emotional self-awareness, but only for participants who were clinically depressed or anxious at the time of the baseline assessment. Mental health literacy and coping self-efficacy did not play mediating roles. LIMITATIONS: Findings suggest that other influential mediators may have not been measured, and future studies could verify the findings by using alternative methodologies, such as comparison with a control group. CONCLUSIONS: Engaging with an emotional wellbeing self-monitoring app may reduce depressive and anxious symptoms, and increase mental well-being. Increases in emotional self-awareness may mediate these changes in clinical populations, and further research is needed to reveal other mechanisms that mental health apps can utilize.

Development of a Mobile Phone App to Support Self-Monitoring of Emotional Well-Being: A Mental Health Digital Innovation.

BACKGROUND: Emotional well-being is a primary component of mental health and well-being. Monitoring changes in emotional state daily over extended periods is, however, difficult using traditional methodologies. Providing mental health support is also challenging when approximately only 1 in 2 people with mental health issues seek professional help. Mobile phone technology offers a sustainable means of enhancing self-management of emotional well-being. OBJECTIVE: This paper aims to describe the development of a mobile phone tool designed to monitor emotional changes in a natural everyday context and in real time. METHODS: This evidence-informed mobile phone app monitors emotional mental health and well-being, and it provides links to mental health organization websites and resources. The app obtains data via self-report psychological questionnaires, experience sampling methodology (ESM), and automated behavioral data collection. RESULTS: Feedback from 11 individuals (age range 16-52 years; 4 males, 7 females), who tested the app over 30 days, confirmed via survey and focus group methods that the app was functional and usable. CONCLUSIONS: Recommendations for future researchers and developers of mental health apps to be used for research are also presented. The methodology described in this paper offers a powerful tool for a range of potential mental health research studies and provides a valuable standard against which development of future mental health apps should be considered.

Mental Health Smartphone Apps: Review and Evidence-Based Recommendations for Future Developments.

BACKGROUND: The number of mental health apps (MHapps) developed and now available to smartphone users has increased in recent years. MHapps and other technology-based solutions have the potential to play an important part in the future of mental health care; however, there is no single guide for the development of evidence-based MHapps. Many currently available MHapps lack features that would greatly improve their functionality, or include features that are not optimized. Furthermore, MHapp developers rarely conduct or publish trial-based experimental validation of their apps. Indeed, a previous systematic review revealed a complete lack of trial-based evidence for many of the hundreds of MHapps available. OBJECTIVE: To guide future MHapp development, a set of clear, practical, evidence-based recommendations is presented for MHapp developers to create better, more rigorous apps. METHODS: A literature review was conducted, scrutinizing research across diverse fields, including mental health interventions, preventative health, mobile health, and mobile app design. RESULTS: Sixteen recommendations were formulated. Evidence for each recommendation is discussed, and guidance on how these recommendations might be integrated into the overall design of an MHapp is offered. Each recommendation is rated on the basis of the strength of associated evidence. It is important to design an MHapp using a behavioral plan and interactive framework that encourages the user to engage with the app; thus, it may not be possible to incorporate all 16 recommendations into a single MHapp. CONCLUSIONS: Randomized controlled trials are required to validate future MHapps and the principles upon which they are designed, and to further investigate the recommendations presented in this review. Effective MHapps are required to help prevent mental health problems and to ease the burden on health systems.

Musical chords and emotion: major and minor triads are processed for emotion.

Musical chords are arguably the smallest building blocks of music that retain emotional information. Major chords are generally perceived as positive- and minor chords as negative-sounding, but there has been debate concerning how early these emotional connotations may be processed. To investigate this, emotional facial stimuli and musical chord stimuli were simultaneously presented to participants, and facilitation of processing was measured via event-related potential (ERP) amplitudes. Decreased amplitudes of the P1 and N2 ERP components have been found to index the facilitation of early processing. If simultaneously presented musical chords and facial stimuli are perceived at early stages as belonging to the same emotional category, then early processing should be facilitated for these congruent pairs, and ERP amplitudes should therefore be decreased as compared to the incongruent pairs. ERPs were recorded from 30 musically naive participants as they viewed happy, sad, and neutral faces presented simultaneously with a major or minor chord. When faces and chords were presented that contained congruent emotional information (happy-major or sad-minor), processing was facilitated, as indexed by decreased N2 ERP amplitudes. This suggests that musical chords do possess emotional connotations that can be processed as early as 200 ms in naive listeners. The early stages of processing that are involved suggest that major and minor chords have deeply connected emotional meanings, rather than superficially attributed ones, indicating that minor triads possess negative emotional connotations and major triads possess positive emotional connotations.