Nonpharmacologic rate control of postoperative atrial fibrillation in the canine sterile pericarditis model.

INTRODUCTION: Postoperative atrial fibrillation (POAF) is common following open heart surgery, and is associated with significant morbidity. Medications used for ventricular rate control of POAF may not be effective in controlling rapid ventricular rates during the postoperative period because of increased sympathetic tone. The purpose of this study was to develop nonpharmacologic rate control of POAF by atrioventricular node (AVN) fat pad stimulation using clinically available temporary pacing wires in the canine sterile pericarditis model. METHODS: We studied 10 sterile pericarditis dogs in the closed-chest state on postoperative days 1-3. The AVN fat pad stimulation (amplitude 2-15 mA; frequency 20 Hz; pulse width 0.03-0.2 ms) was performed during sustained POAF (>5 min). We measured ventricular rate and inefficient ventricular contractions during sustained POAF and compared it with and without AVN fat pad stimulation. Also, the parameters of AVN fat pad stimulation to achieve a rate control of POAF were measured over the postoperative days. RESULTS: Eleven episodes of sustained POAF were induced in 5/10 sterile pericarditis dogs in the closed-chest state on postoperative days 1-2. During POAF, the AVN fat pad stimulation decreased the ventricular rate from 178 ± 52 bpm to 100 ± 8 bpm in nine episodes. Nonpharmacologic rate control therapy successfully controlled the ventricular rate and eliminated inefficient ventricular contractions during POAF for the duration of the AVN fat pad stimulation. The AVN fat pad stimulation output remained relatively stable over the postoperative days. CONCLUSION: During sustained POAF, nonpharmacologic rate control by AVN fat pad stimulation effectively and safely controlled rapid ventricular rates throughout the postoperative period.

Effectiveness of Psychotherapy on Prevention of Suicidal Re-Attempts in Psychiatric Emergencies: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials.

INTRODUCTION: Many psychological interventions aim to prevent suicide, but there is limited information regarding their comparative effectiveness. OBJECTIVES: We conducted a systematic review and network meta-analysis to evaluate the relative effects of psychological interventions for preventing suicide re-attempts in psychiatric emergencies. METHODS: We searched PubMed, Embase, Cochrane, and PsycINFO from inception to December 1, 2022. Selection and data extraction were conducted independently by two reviewers based on prespecified criteria. We evaluated the efficacy of interventions, potential effect moderators, and study quality both within individual studies and across studies. Global and local inconsistencies and publication bias were explored. The primary outcome was suicide re-attempt rate. The network meta-analysis was conducted using the "netmeta" package in R. The protocol was registered with PROSPERO (CRD42021291407). RESULTS: There were 3,155 participants from 26 randomized controlled trials included in the network meta-analysis. Cognitive behavioral therapy (CBT) was the only intervention that was more effective than a common comparator for reducing suicide re-attempts among psychological interventions in both direct and indirect comparisons (odds ratio: [95% confidence interval], 0.46 [0.25-0.85] vs. 0.47 [0.27-0.83]). CBT had the highest score (p score = 0.8727) across the various psychological interventions. Neither global nor local inconsistencies were significant. There was no clear evidence of violations of the transitivity assumption when comparing characteristics of studies across interventions. Publication bias was not suspected for the primary outcome. CONCLUSIONS: CBT may be regarded as a reasonable first-line psychological intervention to prevent re-attempts among people with previous suicide attempts. We observed a moderate quality of evidence supporting an 87% probability of CBT being the best treatment available for preventing suicide re-attempts.

Validation of a new species for studying postoperative atrial fibrillation: Swine sterile pericarditis model.

BACKGROUND: The canine sterile pericarditis model associated with atrial inflammation is an experimental counterpart of postoperative atrial fibrillation (POAF). However, the use of canines for research is restricted by ethics committees in many countries, and social acceptance is declining. OBJECTIVE: To validate the feasibility of the swine sterile pericarditis model as an experimental counterpart to study POAF. METHODS: Seven domestic pigs (35-60 kg) underwent initial pericarditis surgery. On two or more postoperative days in the closed-chest state, we performed electrophysiological measurements of pacing threshold and atrial effective refractory period (AERP) while pacing from the right atrial appendage (RAA) and the posterior left atrium (PLA). The inducibility of POAF (>5 min) by burst pacing was determined in both the conscious and anesthetized closed-chest state. These data were compared to previously published canine sterile pericarditis data for validation. RESULTS: The pacing threshold increased from day 1 to day 3 (2 ± 0.1 to 3.3 ± 0.6 mA in the RAA, 2.5 ± 0.1 to 4.8 ± 0.2 mA in the PLA). Also, the AERP increased from day 1 to day 3 (118 ± 8 to 157 ± 16 ms in the RAA; 98 ± 4 to 124 ± 2 ms in the PLA, both p < .05). Induction of sustained POAF occurred in 43% (POAF CL range 74-124 ms). All electrophysiologic data from the swine model were consistent with the canine model with respect to (1) the range of both pacing threshold and AERP; (2) the progressive increase in threshold and AERP over time; (3) a 40%-50% incidence of POAF. CONCLUSION: A newly developed swine sterile pericarditis model demonstrated electrophysiologic properties consistent with the canine model and patients after open heart surgery.

Impact of the COVID-19 Pandemic on Gender Differences in Depression Based on National Representative Data.

BACKGROUND: Restrictions on daily life and changes in economic structure due to coronavirus disease 2019 (COVID-19) likely would have affected men and women differently. However, there is still a lack of research on the difference between men and women in the amount of change in depression during COVID-19 compared to before COVID-19. Therefore, the researchers investigated gender differences in the magnitude of increase in the prevalence of depression with its severity and individual symptoms during COVID-19 compared with pre-pandemic levels. METHODS: The Korea National Health and Nutrition Examination Survey (KNHANES) 2016 and 2018 were used to assess depression levels pre-pandemic and the KNHANES 2020 for pandemic depression levels. Depression was evaluated using the Patient Health Questionnaire-9 (PHQ-9). To analyze the differences between men and women in the magnitude of the mental health impact of COVID-19, the researchers analyzed the weighted differences in depression prevalence, severity, and individual symptoms during the COVID-19 pandemic compared to before COVID-19 stratified by gender. RESULTS: In men, there were significant increases in weighted prevalence for depression (1.2% percentage point; 95% confidence interval [CI], 0.0-2.3) and severe symptoms of depression (2.6-fold; 95% CI, 1.2-5.7). Among the individual symptoms of depression, significant increases during the pandemic compared to before were: little interest or pleasure in doing things, 1.26-fold; feeling tired or having little energy, 2.2-fold; and suicidal thoughts, 1.7-fold. However, there was no significant difference in prevalence, symptoms severity, and any symptom before and during COVID-19 in women. CONCLUSIONS: Because the pandemic is likely to increase mental problems of the affected over time due to such problems as financial stress and joblessness or post-infection health issues, the researchers anticipate an increase in the prevalence of some mental illnesses. In particular, since the suicide rate of men is higher than that of women, from a public health perspective, active interventions are needed to prevent an increase in the suicide rate due to COVID-19. It is also necessary to establish national policies to overcome the psychological, social, and economic losses resulting from COVID-19.

Paradigm shifts in electrophysiological mechanisms of atrial fibrillation.

Determining the sequence of activation is a major source of information for understanding the electrophysiological mechanism(s) of atrial fibrillation (AF). However, the complex morphology of the electrograms hampers their analysis, and has stimulated generations of electrophysiologists to develop a large variety of technologies for recording, pre-processing, and analysis of fibrillation electrograms. This variability of approaches is mirrored by a large variability in the interpretation of fibrillation electrograms and, thereby, opinions regarding the basic electrophysiological mechanism(s) of AF vary widely. Multiple wavelets, different types of re-entry including rotors, double layers, multiple focal activation patterns all have been advocated, and a comprehensive and commonly accepted paradigm for the fundamental mechanisms of AF is still lacking. Here, we summarize the Maastricht perspective and Cleveland perspective regarding AF mechanism(s). We also describe some of the key observations in mapping of AF reported over the past decades, and how they changed over the years, often as results of new techniques introduced in the experimental field of AF research.

Gaming patterns and related symptoms in adolescents using cluster analysis: Baseline results from the Internet User Cohort for Unbiased Recognition of Gaming Disorder in Early Adolescence (iCURE) study.

PURPOSE: The risk and protective factors of Internet gaming disorder (IGD) could vary by individual. The identification of more homogeneous subgroups may lead to better understanding of gaming behaviors and their consequences in adolescents. The purpose of this study was to investigate the prevalence of IGD among the subgroups defined by cluster analysis in adolescents. METHODS: A total of 2319 adolescents were enrolled in the Internet User Cohort for Unbiased Recognition of Gaming Disorder in Early Adolescence (iCURE) study at baseline. Self-reported IGD was assessed with a DMS-5 adapted measurement. Smartphone addiction, musculoskeletal discomfort, and dry eye symptoms were evaluated by self-administered questionnaires. Cluster analysis was performed using risk and protective factors of IGD after considering multicollinearity. RESULTS: Three different clusters were identified. Cluster 1 (19.2%) was users with combined potential psychological and social issues. Cluster 2 (32.3%) was users with potential social but no psychological issues. Cluster 3 (45.6%) was users with no potential issues of either a social or psychological nature. Adolescents from both clusters 1 and 2 showed higher degrees of IGD, smartphone addiction, musculoskeletal discomfort, and dry eye symptoms than did those from cluster 3. Also compared with adolescents in cluster 3, those in cluster 1 showed statistically higher risks of IGD (aOR:11.9, 95%CI:7.5-19.9), smartphone addiction (aOR:5.4, 95%CI:4.0-7.2), musculoskeletal discomfort (aOR:2.6, 95%CI:2.1-7.4), and dry eye symptoms (aOR:3.8, 95%CI:3.0-4.9). Those in cluster 2 also showed statistically higher risk of IGD, smartphone addiction, musculoskeletal discomfort, and dry eye symptoms compared with cluster 3 (aOR:4.5, 95%CI:2.8-7.6; aOR:2.8, 95%CI:2.1-3.7; aOR:1.6, 95%CI:1.3-1.9; and aOR:1.9, 95%CI:1.6-2.4, respectively). CONCLUSIONS: Clustering based on the risk and preventive factors of IGD may be suitable for determination of high risk of IGD in adolescents. However, we need to confirm the usefulness and clinical application of the classifications by observing their longitudinal changes.

Prediction of emergency department patient disposition decision for proactive resource allocation for admission.

We investigate the capability of information from electronic health records of an emergency department (ED) to predict patient disposition decisions for reducing "boarding" delays through the proactive initiation of admission processes (e.g., inpatient bed requests, transport, etc.). We model the process of ED disposition decision prediction as a hierarchical multiclass classification while dealing with the progressive accrual of clinical information throughout the ED caregiving process. Multinomial logistic regression as well as machine learning models are built for carrying out the predictions. Utilizing results from just the first set of ED laboratory tests along with other prior information gathered for each patient (2.5 h ahead of the actual disposition decision on average), our model predicts disposition decisions with positive predictive values of 55.4%, 45.1%, 56.9%, and 47.5%, while controlling false positive rates (1.4%, 1.0%, 4.3%, and 1.4%), with AUC values of 0.97, 0.95, 0.89, and 0.84 for the four admission (minor) classes, i.e., intensive care unit (3.6% of the testing samples), telemetry unit (2.2%), general practice unit (11.9%), and observation unit (6.6%) classes, respectively. Moreover, patients destined to intensive care unit present a more drastic increment in prediction quality at triage than others. Disposition decision classification models can provide more actionable information than a binary admission vs. discharge prediction model for the proactive initiation of admission processes for ED patients. Observing the distinct trajectories of information accrual and prediction quality evolvement for ED patients destined to different types of units, proactive coordination strategies should be tailored accordingly for each destination unit.

A partial mediation effect of father-child attachment and self-esteem between parental marital conflict and subsequent features of internet gaming disorder in children: a 12-month follow-up study.

BACKGROUND: This study evaluated whether parent-child attachment and self-esteem may mediate the relationship between parental marital conflict and increases in features of internet gaming disorder (IGD) in children at 1 year. METHODS: The baseline and one-year follow-up data for 268 pre-teens aged between 9 and 10 from the Internet User Cohort for Unbiased Recognition of Gaming Disorder in Early Adolescence (iCURE) study were collected. The students were children at low risk for IGD in the initial self-reported assessment, anyone living with both parents, current game user at baseline, and those who completed a 12-month follow-up assessment. The Internet Game Use-Elicited Symptom Screen (IGUESS) was used to identify increases in IGD features at 12 months. To examine a potential mediation effect, structural equation modeling was performed. RESULTS: The direct effect was statistically significant, and parental marital conflict at baseline significantly predicted the increases in IGD features in children at the 12-month follow-up after adjusting for gender, sex, socioeconomic status, and baseline IGUESS score (ß = 0.206, P = 0.003). The indirect effect showed that attachment to fathers through self-esteem was a significant mediating effect (ß = 0.078, P = 0.045). Parental marital conflicts were associated with increases in IGD features in children through poor father-child attachment, and in turn, the lower levels of self-esteem in the children. CONCLUSIONS: Parents, especially fathers, should make an effort to bond with their children to reduce the risk of their children's developing the IGD features.

Epidemiology of Bearing Dislocations After Mobile-Bearing Unicompartmental Knee Arthroplasty: Multicenter Analysis of 67 Bearing Dislocations.

BACKGROUND: This study investigated the epidemiology and causes of bearing dislocations following mobile-bearing unicompartmental knee arthroplasty (MUKA) and determined whether the incidence of primary bearing dislocations decreases as surgeon experience increases. METHODS: We retrospectively reviewed the bearing dislocations following MUKAs performed by 14 surgeons with variable experience levels. Causes of bearing dislocations were determined based on the surgical records, radiographs, and operator's suggestion. Using a chi-squared test, the incidence of bearing dislocation was compared between the first 50, the second 50, and the next 100 unicompartmental knee arthroplasties (UKAs) of each surgeon's cohort. RESULTS: There were 67 (3.6%) bearing dislocations from 1853 MUKAs. The mean time to bearing dislocations after index MUKAs was 33 months (range, 1-144 months); 55% of the bearing dislocations occurred within 2 years after the index MUKAs. Primary bearing dislocations (n = 58) were the most common, followed by secondary (n = 6) and traumatic dislocations (n = 3). There was no significant difference in the incidence of bearing dislocation between the first 50 and second 50 UKAs for each surgeon. Two surgeons showed a significant decrease in bearing dislocations in their second 100 UKAs, while the other surgeons did not show a difference between their first 100 and second 100 UKAs. CONCLUSION: Most bearing dislocations after MUKAs were related to technical errors such as component malposition or gap imbalance. This study did not confirm that the incidence of bearing dislocations decreases as the number of cases increases. LEVEL OF EVIDENCE: IV, Case series.

Patient-reported outcomes correlate with functional scores after opening-wedge high tibial osteotomy: a clinical study.

PURPOSE: The purpose of this study was to assess post-operative patient subjective satisfaction and to analyze associated peri-operative factors following biplanar medial open wedge high tibial osteotomy (OWHTO). METHODS: The study cohort consisted of 88 patients with a minimum of two years of follow-up. Patient satisfaction was evaluated with a questionnaire that assessed (1) overall satisfaction, (2) pain relief, (3) daily living functions, and (4) cosmesis. Patients were categorized into two groups (satisfied or unsatisfied) based on overall satisfaction questionnaire. Pre- and post-operative objective clinical statuses were assessed with a knee scoring system based on the American Knee Society (AKS), the Western Ontario McMaster University Osteoarthritis Index (WOMAC), and range of motion. RESULTS: Of the 88 patients, 85.2% were graded as satisfied according to the overall satisfaction estimation. The percentage of patients satisfied with pain relief, daily living functions, and cosmesis were 85.2%, 86.4%, and 86.4%, respectively. Multivariable logistic regression analysis demonstrated that pre-operative Hip-Knee-Ankle angle (HKAA) (odds ratio (OR) = 1.812), post-operative AKS knee score (OR = 1.156), and post-operative HKAA (OR = 0.717) were significantly associated with overall satisfaction. Pre-operative HKAA (OR = 1.436), post-operative WOMAC activity score (OR = 0.865), and post-operative HKAA (OR = 0.505) were significant predictors for satisfaction with pain reduction, daily living functions, and cosmesis, respectively. CONCLUSIONS: Biplanar medial OWHTO is an effective treatment for osteoarthritis with varus deformity in terms of subjective satisfactory outcome. Several factors, including pre- and post-operative HKAA, post-operative AKS and WOMAC score, were significant predictors for subjective satisfaction. LEVEL OF EVIDENCE: Level III.

What Factors Are Associated With Femoral Component Internal Rotation in TKA Using the Gap Balancing Technique?

BACKGROUND: When using the gap-balancing technique for TKA, excessive medial release and varus proximal tibial resection can be associated with internal rotation of the femoral component. Previous studies have evaluated the causes of femoral component rotational alignment with a separate factor analysis using unadjusted statistical methods, which might result in treatment effects being attributed to confounding variables. QUESTIONS/PURPOSES: (1) What pre- and intraoperative factors are associated with internal rotation of the femoral component in TKA using the gap balancing technique? (2) To what degree does femoral component rotation as defined by the navigation system differ from rotation as measured by postoperative CT? METHODS: Three hundred seventy-seven knees that underwent computer-assisted primary TKA attributable to degenerative osteoarthritis with varus or mild valgus alignment in which medial soft tissue release was performed, and those with preoperative radiographs including preoperative CT between October 2007 and June 2014 were included in the study. To achieve a balanced mediolateral gap, the structures released during each medial release step were as follows: Step 1, deep medial collateral ligament (MCL); Step 2, superficial MCL (proximal, above the pes anserine tendon) and semimembranosus tendon; and Step 3, the superficial MCL (distal, below the pes anserine tendon). Knees with internal rotation of the femoral component, which was directed by navigation, to achieve a rectangular mediolateral flexion gap were considered cases, and knees without internally rotated femoral components were considered controls. Univariable analysis of the variables (age, sex, BMI, operated side, preoperative hip-knee-ankle angle, preoperative medial proximal tibial angle, preoperative rotation degree of the clinical transepicondylar axis [TEA] relative to the posterior condylar axis [PCA], coronal angle of resected tibia, resection of the posterior cruciate ligament, type of prosthesis, and extent of medial release) of cases and controls was performed, followed by a multivariable logistic regression analysis on those factors where p equals 0.15 or less. For an evaluation of navigation error, 88 knees that underwent postoperative CT were analyzed. Postoperative CT scans were obtained for patients with unexplained pain or stiffness after the operations. Using the paired t-test and Pearson's correlation analysis, the postoperative TEA-PCA measured with postoperative CT was compared with theoretical TEA-PCA, which was calculated with preoperative TEA-PCA and actual femoral component rotation checked by the navigation system. RESULTS: After controlling for a relevant confounding variable such as postoperative hip-knee-ankle angle, we found that the extent of medial release (Step 1 as reference; Step 2: odds ratio [OR], 5.7, [95% CI, 2.2-15]; Step 3: OR, 22, [95% CI, 7.8-62], p < 0.001) was the only factor we identified that was associated with internal rotation of the femoral component. With the numbers available, we found no difference between the mean theoretical postoperative TEA-PCA and the postoperative TEA-PCA measured using postoperative CT (4.8° ± 2.7º versus 5.0° ± 2.3º; mean difference, 0.2° ± 1.5º; p = 0.160). CONCLUSIONS: Extent of medial release was the only factor we identified that was associated with internal rotation of the femoral component in gap-balancing TKA. To avoid internal rotation of the femoral component, we recommend a carefully subdivided medial-releasing technique, especially for the superficial MCL because once the superficial MCL has been completely released it cannot easily be restored. LEVEL OF EVIDENCE: Level III, therapeutic study.

Typology of Internet gaming disorder and its clinical implications.

Various perspectives exist regarding Internet gaming disorder. While the concept of behavioral addiction is gaining recognition, some view the phenomenon as merely excessive indulgence in online pastimes. Still, in recent years, complaints from patients or their family members about problems related to Internet use, particularly Internet gaming, have become more common. However, the clinical picture of Internet gaming disorder could be obscured by its heterogeneous manifestations with other intertwined factors, such as psychiatric comorbidities, neurodevelopmental factors, sociocultural factors, and game-related factors, which may influence the pathogenesis as well as the clinical course. To mitigate such problems, clinicians should be able to consider diverse aspects related to Internet gaming disorder. Classifying such a heterogeneous problem into subtypes that share a similar etiology or phenomenology may provide additional clues in the diagnostic process and allow us to designate available clinical resources for particularly vulnerable factors. In this review paper, we suggest a typology of 'impulsive/aggressive,' 'emotionally vulnerable,' 'socially conditioned,' and 'not otherwise specified' as subtypes of the heterogeneous phenomena of pathological Internet gaming. The implications of these subtypes for assessment and treatment planning will also be highlighted.

Tibial component rotation during the unicompartmental knee arthroplasty: is the anterior superior iliac spine an appropriate landmark?

PURPOSE: No "ideal" landmark for tibial component rotation in medial unicompartmental knee arthroplasty (UKA) has been suggested by a biomechanical and clinical study. The aim of this study was to investigate whether the anterior superior iliac spine (ASIS) could provide a consistent rotational landmark of the tibial component during mobile-bearing medial UKA using computed tomography (CT). METHODS: During sagittal tibial resection, we utilized the ASIS as a rotational landmark. In 47 knees that underwent postoperative CT scans after medial UKA, the tibial component position was assessed by drawing a line tangential to the lateral wall of the tibial component. Rotation of the tibial component was measured using two reference lines: a line perpendicular to the posterior cortical rim of the tibia (angle α) and Akagi's line (angle ß). Instant bearing position and posterior cruciate ligament (PCL) fossa involvement were also evaluated. External rotation of the tibial component relative to each reference line was considered positive values. RESULTS: The mean α and ß angles were 8.0° ± 6.1° (range -4.0 to 24.3) and 8.7° ± 4.8° (range 1.9-25.2), respectively. Fourteen knees (29.8 %) showed PCL fossa involvement of the tibial resection margin. One bearing showed complete 180° rotation at 2 weeks postoperatively. CONCLUSION: Due to the wide variation and inherent difficulty of identifying the ASIS during the operation, it is not recommended for guidance of sagittal tibial resection during medial UKA. In cases of inappropriate tibia component rotation, risk of PE bearing spinning and iatrogenic PCL injury should be reminded after medial UKA. LEVEL OF EVIDENCE: IV.

Sagittal osteotomy inclination in medial open-wedge high tibial osteotomy.

PURPOSE: Unlike postoperative changes in posterior tibial slope after medial open-wedge high tibial osteotomy, sagittal osteotomy inclination has not been examined. It has been recommended that the osteotomy line in the sagittal plane be parallel to the medial posterior tibial slope. The purpose of this study was to determine the frequency of parallel osteotomy in medial open-wedge high tibial osteotomy. METHODS: To determine the sagittal osteotomy inclination, the angle between the medial joint line and the osteotomy line was measured in the lateral radiograph. A positive angle value indicates that the osteotomy is anteriorly inclined relative to the medial posterior tibial slope. Correlation between the sagittal osteotomy inclination and posterior tibial slope was also evaluated. RESULTS: The mean sagittal osteotomy inclination was 15.1 ± 7.5°. The majority 87.1 % of knees showed an anterior-inclined osteotomy. There was a significantly positive correlation between the postoperative posterior tibial slope and the sagittal osteotomy inclination (r, 0.33; 95 % confidence interval (CI) 0.19-0.46; P < 0.001). The postoperative change in posterior tibial slope also showed a significantly positive correlation with the sagittal osteotomy inclination (r, 0.35; 95 % CI 0.21-0.47; P < 0.001). CONCLUSION: Although parallel osteotomy in the sagittal plane relative to the medial joint line was planned, only 12.9 % of cases achieved osteotomy parallel to the medial posterior tibial slope in the sagittal plane. Because of high rate of the anterior-inclined osteotomy and their correlations with posterior tibial slope, surgeons should make all efforts to perform parallel osteotomy relative to medial posterior tibial slope. LEVEL OF EVIDENCE: IV.

Simultaneous Biatrial High-Density (510-512 Electrodes) Epicardial Mapping of Persistent and Long-Standing Persistent Atrial Fibrillation in Patients: New Insights Into the Mechanism of Its Maintenance.

BACKGROUND: The mechanism(s) of persistent and long-standing persistent (LSP) atrial fibrillation (AF) is/are poorly understood. We performed high-density, simultaneous, biatrial, epicardial mapping of persistent and LSP AF in patients undergoing open heart surgery (1) to test the hypothesis that persistent and LSP AF are due to ≥ 1 drivers, either focal or reentrant, and (2) to characterize associated atrial activation. METHODS AND RESULTS: Twelve patients with persistent and LSP AF (1 month to 9 years duration) were studied at open heart surgery. During AF, electrograms were recorded from both atria simultaneously for 1 to 5 minutes from 510 to 512 epicardial electrodes with ECG lead II. Thirty-two consecutive seconds of activation sequence maps were produced per patient. During AF, multiple foci (QS unipolar atrial electrograms) of different cycle lengths (mean, 175 ± 18 ms) were present in both atria in 11 of 12 patients. Foci (2-4 per patient, duration 5-32 s) were either sustained or intermittent, were predominantly found in the lateral left atrial free wall, and likely acted as drivers. Random and nonrandom breakthrough activation sites (initial r or R in unipolar atrial electrograms) were also found. In 1 of 12 patients, only breakthrough sites were found. All wave fronts emanated from foci and breakthrough sites, and largely either collided or merged with each other at variable sites. Repetitive focal QS activation occasionally generated repetitive wannabe reentrant activation in 5 of 12 patients. No actual reentry was found. CONCLUSIONS: During persistent and LSP AF in 12 patients, wave fronts emanating from foci and breakthrough sites maintained AF. No reentry was demonstrated.

Termination of Atrial Flutter and Fibrillation by K201's Metabolite M-II: Studies in the Canine Sterile Pericarditis Model.

INTRODUCTION: K201, a 1,4-benzodiazepine derivative, acts on multiple cardiac ion channels and the ryanodine receptor. We tested whether administration of M-II, the main metabolite of K201, would terminate induced atrial flutter (AFL) or atrial fibrillation (AF) in the canine sterile pericarditis model. METHODS: In 6 dogs, electrophysiologic studies were performed at baseline and after drug administration, measuring atrial effective refractory period (AERP), and conduction time from 3 sites during pacing at cycle lengths (400, 300, and 200 milliseconds) on postoperative days 1-4. In 12 induced episodes of sustained AF/AFL (2/10, respectively), M-II was administered intravenously to test efficacy. Five of the AFL episodes were studied in the open chest state during simultaneous multisite atrial mapping. RESULTS: M-II terminated 2/2 AF and 8/10 AFL episodes, prolonged AERP (P < 0.05), significantly increased atrial pacing capture thresholds but did not significantly change atrial conduction time. AFL CL prolongation was largely explained by prolonged conduction in an area of slow conduction in the reentrant circuit. AFL terminated with block in the area of slow conduction. CONCLUSIONS: M-II was very effective in terminating AFL/AF in the canine sterile pericarditis model. AFL terminated due to block in the area of slow conduction of the reentrant circuit.

Insights into new-onset atrial fibrillation following open heart surgery and implications for type II atrial flutter.

AIMS: Postoperative atrial fibrillation (POAF), new-onset AF after open heart surgery (OHS), is thought to be related to pericarditis. Based on AF studies in the canine sterile pericarditis model, we hypothesized that POAF in patients after OHS may be associated with a rapid, regular rhythm in the left atrium (LA), suggestive of an LA driver maintaining AF. The aim of this study was to test the hypothesis that in patients with POAF, atrial electrograms (AEGs) recorded from at least one of the two carefully selected LA sites would manifest a rapid, regular rhythm with AEGs of short cycle length (CL) and constant morphology, but a selected right atrial (RA) site would manifest AEGs with irregular CLs and variable morphology. METHODS AND RESULTS: In 44 patients undergoing OHS, AEGs recorded from the epicardial surface of the RA, the LA portion of Bachmann's bundle, and the posterior LA during sustained AF were analysed for regularity of CL and morphology. Sustained AF occurred in 15 of 44 patients. Atrial electrograms were recorded in 11 of 15 patients; 8 of 11 had rapid, regular activation with constant morphology recorded from at least one LA site; no regular AEG sites were present in 3 of 11 patients. CONCLUSIONS: Atrial electrograms recorded during sustained POAF frequently demonstrated rapid, regular activation in at least one LA site, consistent with a driver maintaining AF.

Gaze-Assisted User Intention Prediction for Initial Delay Reduction in Web Video Access.

Despite the remarkable improvement of hardware and network technology, the inevitable delay from a user's command action to a system response is still one of the most crucial influence factors in user experiences (UXs). Especially for a web video service, an initial delay from click action to video start has significant influences on the quality of experience (QoE). The initial delay of a system can be minimized by preparing execution based on predicted user's intention prior to actual command action. The introduction of the sequential and concurrent flow of resources in human cognition and behavior can significantly improve the accuracy and preparation time for intention prediction. This paper introduces a threaded interaction model and applies it to user intention prediction for initial delay reduction in web video access. The proposed technique consists of a candidate selection module, a decision module and a preparation module that prefetches and preloads the web video data before a user's click action. The candidate selection module selects candidates in the web page using proximity calculation around a cursor. Meanwhile, the decision module computes the possibility of actual click action based on the cursor-gaze relationship. The preparation activates the prefetching for the selected candidates when the click possibility exceeds a certain limit in the decision module. Experimental results show a 92% hit-ratio, 0.5-s initial delay on average and 1.5-s worst initial delay, which is much less than a user's tolerable limit in web video access, demonstrating significant improvement of accuracy and advance time in intention prediction by introducing the proposed threaded interaction model.

Rab3a promotes brain tumor initiation and progression.

The Rab protein family is composed of small GTP-binding proteins involved in intracellular vesicle trafficking. In particular, Rab3a which is one of four Rab3 proteins (a, b, c, and d isoforms) is associated with synaptic vesicle trafficking in normal brain. However, despite the elevated level of Rab3a in tumors, its role remains unclear. Here we report a tumorigenic role of Rab3a in brain tumors. Elevated level of Rab3a expression in human was confirmed in both glioma cell lines and glioblastoma multiforme patient specimens. Ectopic Rab3a expression in glioma cell lines and primary astrocytes promoted cell proliferation by increasing cyclin D1 expression, induced resistance to anti-cancer drug and irradiation, and accelerated foci formation in soft agar and tumor formation in nude mice. The overexpression of Rab3a augmented the tumorsphere-forming ability of glioma cells and p53(-/-) astrocytes and increased expression levels of various stem cell markers. Taken together, our results indicate that Rab3a is a novel oncogene involved in glioma initiation and progression.

Tunnel volume enlargement after posterior cruciate ligament reconstruction: comparison of achilles allograft with mixed autograft/allograft--a prospective computed tomography study.

PURPOSE: The purpose of this study was to evaluate and compare femoral and tibial tunnel volume enlargement (TVE) after arthroscopic posterior cruciate ligament (PCL) reconstruction by remnant bundle preservation using Achilles allograft or mixed graft. METHODS: Seventy-eight patients undergoing primary arthroscopic single-bundle PCL reconstruction were initially included. Fifty-six of these patients underwent follow-up for a minimum of 1 year postoperatively and were divided into 2 groups: group A received Achilles allograft (n = 27), and group B received mixed graft (n = 29). The clinical evaluation included the International Knee Documentation Committee rating, Lysholm score, Tegner activity score, and Telos stress test (Telos, Weiterstadt, Germany). All of the patients were evaluated for TVE by computed tomography scanning at the 1-year follow-up; the results were compared with the data from 1 week postoperatively. A volume increment of more than 44%, which indicates 2 mm of widening of the tunnel diameter, was defined as TVE. RESULTS: The overall incidence of TVE after single-bundle PCL reconstruction was 3.6% (2 of 56 patients) for the femoral tunnel and 5.4% (3 of 56 patients) for the tibial tunnel. The overall mean tunnel difference between 1 week postoperatively and the final follow-up was 12.0% for the femoral tunnel and 10.6% for the tibial tunnel. The mean femoral TVE was 10.1% in group A and 13.8% in group B; the mean tibial TVE was 9.9% in group A and 11.2% in group B. These differences were not statistically significant. The functional outcome was improved in both groups, showing no statistical difference at the 1-year follow-up. CONCLUSIONS: The femoral and tibial TVE caused by single-bundle PCL reconstruction using the remnant bundle-preservation technique showed no significant differences between the Achilles allograft and the mixed graft over a short-term follow-up. Furthermore, the overall incidence of TVE in PCL reconstruction in this study was low. LEVEL OF EVIDENCE: Level II, prospective comparative study.