Pacing Pattern Research Articles

Evolution of 1500-m Olympic Running Performance.

This study determined the evolution of performance and pacing for each winner of the men's Olympic 1500-m running track final from 1924 to 2020. Data were obtained from publicly available sources. When official splits were unavailable, times from sources such as YouTube were included and interpolated from video records. Final times, lap splits, and position in the peloton were included. The data are presented relative to 0 to 400m, 400 to 800m, 800 to 1200m, and 1200 to 1500m. Critical speed and D' were calculated using athletes' season's best times. Performance improved ∼25seconds from 1924 to 2020, with most improvement (∼19s) occurring in the first 10 finals. However, only 2 performances were world records, and only one runner won the event twice. Pacing evolved from a fast start-slow middle-fast finish pattern (reverse J-shaped) to a slower start with steady acceleration in the second half (J-shaped). The coefficient of variation for lap speeds ranged from 1.4% to 15.3%, consistent with a highly tactical pacing pattern. With few exceptions, the eventual winners were near the front throughout, although rarely in the leading position. There is evidence of a general increase in both critical speed and D' that parallels performance. An evolution in the pacing pattern occurred across several "eras" in the history of Olympic 1500-m racing, consistent with better trained athletes and improved technology. There has been a consistent tactical approach of following opponents until the latter stages, and athletes should develop tactical flexibility, related to their critical speed and D', in planning prerace strategy.

Highly Trained Biathletes With a Fast-Start Pacing Pattern Improve Time-Trial Skiing Performance by Pacing More Evenly.

In sprint biathlon, a J-shaped pacing pattern is commonly used. We investigated whether biathletes with a fast-start pacing pattern increase time-trial skiing and shooting performance by pacing more evenly. Thirty-eight highly trained biathletes (∼21y, 27 men) performed an individual 7.5 (3 × 2.5km for women) or 10-km (3 × 3.3km for men) time trial on roller skis with a self-selected pacing strategy (day 1). Prone (after lap 1) and standing shooting (after lap 2) stages were performed using paper targets. Based on their pacing strategy in the first time trial (ratio between the initial ∼800-m segment pace on lap 1 and average ∼800-m segment pace on laps 1-3), participants were divided into an intervention group with the fastest starting pace (INT, n = 20) or a control group with a more conservative starting pace (CON, n = 18). On day 2, INT was instructed to reduce their starting pace, while CON was instructed to maintain their day 1 strategy. INT increased their overall time-trial performance more than CON from day 1 to day 2 (mean ± 95% CI; 1.5% ± 0.7% vs 0.0% ± 0.9%, P = .02). From day 1 to day 2, INT reduced their starting pace (5.0% ± 1.5%, P < .01), with reduced ratings of perceived exertion during lap 1 (P < .05). For CON, no change was found for starting pace (-0.8% ± 1.2%) or ratings of perceived exertion between days. No differences were found for shooting performance for either group. Highly trained biathletes with a pronounced fast-start pattern improve skiing performance without any change in shooting performance by pacing more evenly.

Performance and pacing of professional IRONMAN triathletes: the fastest IRONMAN World Championship ever—IRONMAN Hawaii 2022

Pacing during cycling and running in an IRONMAN triathlon has been investigated in only one study with elite IRONMAN triathletes. We have, however, no knowledge of how professional triathletes pace during an IRONMAN World Championship. To investigate the split-by-split speed, pacing strategies and pacing variability in professional female and male IRONMAN World Championship participants in the fastest IRONMAN World Championship ever in IRONMAN Hawaii 2022. For both cycling and running, 25 specific split times were recorded in each discipline. The best 30 men and 30 women overall were chosen from the official IRONMAN website database for further analysis. They were divided into three performance groups: Top 10, 11–20th place, and 21st–30th place. Mean speed, individual linear regressions with the corresponding correlation coefficients, and coefficient of variation were calculated to assess split-by-split speed, pacing strategies, and pacing variability, respectively. In both men’s and women’s cycling and running segments, the top ten participants exhibited faster split times compared to the slower performance groups. Notably, no discernible differences existed between the 11–20th and 21st–30th place in men’s cycling and women’s running times. Conversely, in men’s running and women’s cycling segments, those in the 11–20th place displayed quicker times than those in the 21st–30th place. In the cycling segment across all groups, men demonstrated a more negative pacing pattern (indicating an increase in speed), whereas women exhibited more consistent pacing. In the running segment, the top 10 men and all women’s groups showcased relatively similar slightly positive pacing profiles. However, men ranking 11–20th and 21st–30th displayed more pronounced positive pacing strategies, implying a more significant decline in speed over time. In terms of cycling, the variability in pacing remained relatively consistent across the three performance groups. Conversely, during the running segment, the top ten male triathletes and those in the 11–20th place displayed lower pacing variability than their counterparts in the 21st–30th position place and all women’s groups. In summary, performance and pacing were examined in professional male and female IRONMAN World Championship participants during IRONMAN Hawaii 2022. Top performers showed faster cycling and running split times, with differences in pacing strategies between sexes. The pacing was more consistent in cycling, while running pacing varied more, particularly among male triathletes in different performance groups.

Pacing Strategy of 800 m and 1500 m Freestyle Swimming Finals in the World Championships According to the Performance in Males and Females of Different Age Groups

Pacing strategy refers to the distribution of effort and speed throughout the race to achieve optimal performance. This study aims to understand whether the choice of pacing strategy in swimming depends on the length of competitions and how sex, age, and performance level influence this strategy. Participants were the finalists of the 800 m and 1500 m freestyle events at the elite and junior world championships in 2022–2023. Race outcomes and pacing parameters were compared between the two distances and across different groups of swimmers. Swimmers in both distances did not break world records. Pacing strategy generally followed a U-shape with significant differences in the frequency and duration of speed changes between the two distances. The 800 m exhibited more frequent changes in acceleration, while the 1500 m events generally followed a more consistent time-series pattern. There were differences in pacing strategies between males and females and between junior and elite swimmers. Swimmers closer to world records showed more consistent pacing patterns compared to those farther from records. This study suggests that pacing strategies are influenced by race distance, sex, age, and performance level. The research highlights the complex interplay between physiological and psychological factors that shape a swimmer’s decision-making during a race.

Changes in pacing variation with increasing race duration in ultra-triathlon races

Despite the increasing scientific interest in the relationship between pacing and performance in endurance sports, little information is available about pacing and pacing variation in ultra-endurance events such as ultra-triathlons. Therefore, we aimed to investigate the trends of pacing, pacing variation, the influence of age, sex, and performance level in ultra-triathlons of different distances. We analysed 969 finishers (849 men, 120 women) in 46 ultra-triathlons longer than the original Ironman® distance (e.g., Double-, Triple-, Quintuple- and Deca Iron ultra-triathlons) held from 2004 to 2015. Pacing speed was calculated for every cycling and running lap. Pacing variation was calculated as the coefficient of variation (%) between the average speed of each lap. Performance level (i.e., fast, moderate, slow) was defined according to the 33.3 and 66.6 percentile of the overall race time. A multivariate analysis (two-way ANOVA) was applied for the overall race time as the dependent variable with ‘sex’ and ‘age group’ as independent factors. Another multivariate model with ‘age’ and ‘sex’ as covariates (two-way ANCOVA) was applied with pacing variation (cycling and running) as the dependent variable with ‘race’ and ‘performance level’ as independent factors. Different pacing patterns were observed by event and performance level. The general pacing strategy applied was a positive pacing. In Double and Triple Iron ultra-triathlon, faster athletes paced more evenly with less variation than moderate or slower athletes. The variation in pacing speed increased with the length of the race. There was no significant difference in pacing variation between faster, moderate, and slower athletes in Quintuple and Deca Iron ultra-triathlon. Women had a slower overall performance than men. The best overall times were achieved at the age of 30–39 years. Successful ultra-triathlon athletes adapted a positive pacing strategy in all race distances. The variation in pacing speed increased with the length of the race. In shorter ultra-triathlon distances (i.e., Double and Triple Iron ultra-triathlon), faster athletes paced more evenly with less variation than moderate or slower athletes. In longer ultra-triathlon distances (i.e., Quintuple and Deca Iron ultra-triathlon), there was no significant difference in pacing variation between faster, moderate, and slower athletes.

Pacing Patterns of Half-Marathon Runners: An analysis of ten years of results from Gothenburg Half Marathon

Abstract The Gothenburg Half Marathon is one of the world’s largest half marathon races with over 40 000 participants each year. In order to reduce the number of runners risking over-straining, injury, or collapse, we would like to provide runners with advice to appropriately plan their pacing. Many participants are older or without extensive training experience and may particularly benefit from such pacing assistance. Our aim is to provide this with the help of machine learning. We first analyze a large publicly available dataset of results from the years 2010 - 2019 (n = 423 496) to identify pacing patterns related to age, sex, ability, and temperature of the race day. These features are then used to train machine learning models for predicting runner’s finish time and to identify which runners are at risk of making severe pacing errors and which ones seem set to pace well. We find that prediction of finish time improves over the current baseline, while identification of pacing patterns correctly identifies over 70% of runners at risk of severe slowdowns, albeit with many false positives.

Surface electromyography changes of male athletes during 2000 m rowing ergometer test

This study aimed to investigate the changes in surface electromyography (EMG) in four anatomical segments of three muscles during a 2000 m rowing ergometer test. 19 healthy male rowers were requested to perform the test. Surface electrodes were attached to their vast medialis (VAM), erector spinae (ERS) and latissimus dorsi (LD) muscles. Raw EMG signals were presented at five different distance points: start (D0), 500 m (D1), 1000 m (D2), 1500 m (D3) and 2000 m (D4). The mean velocity and power were greater during 0–500 m and 1500–2000 m phases compared to 500–1000 m and 1000–1500 m phases (p &lt; 0.01). Integrated Electromyography (iEMG) of VAM was significantly higher at the start and 2000 m compared to consecutive points (p &lt; 0.05). The peak root mean square (pRMS) of ERS muscles was significantly higher at the start and 2000 m (p &lt; 0.05). The frequency domain indexes mean frequency (MNF) and median frequency (MDF) of all muscles were significantly reduced at 1500 m compared to 1000 m (p &lt; 0.05). However, no significant changes were observed in time domain indexes of LD muscles at any distance points (p &gt; 0.05). A “fast start-speed maintains-final sprint” pacing pattern was observed during the 2000 m all-out rowing ergometer test. The EMG activation rates of VAM and ERS muscles were greater at the start and final phases, contributing to the increase in power. The decline in MNF and MDF of all three muscles at 1500 m could be related to greater muscle fatigue at this point. When using EMG to analyze endurance exercise, the results were dependent on the length of the test. Although not all EMG indexes were sensitive enough to detect these changes, combing them with different indicators for a comprehensive analysis might be considered.

Activity Pacing Patterns In Adults With Disabilities

PURPOSE: Activity pacing is a self-management strategy targeting inefficient activity patterns to help people with disabilities to engage in an active lifestyle. This study explored how two pacing patterns, even and fluctuating, are associated with personal characteristics in people with disabilities: personal factors, perceived fatigue, self-reported attitudes towards activity pacing, and physical activity. METHODS: 58 Participants wore an Actiheart activity monitor for one week and filled in the Fatigue Severity Scale assessing perceived fatigue, the Adapted-SQUASH assessing self-reported physical activity, and a questionnaire assessing perceived attitudes towards activity pacing. Based on a previously reported method, the median split over the week of the standard deviation of accelerometer-derived activity over the day was used (measure of activity pacing). Participants were defined as even or fluctuating pacers. The differences in personal characteristics for the two groups were examined using Independent samples t-test and Mann Whitney U test. RESULTS: Even pacers (N = 27) were older (60.4 ± 16.3 yr, t(df) = 2.3(56), p = .029) and had a higher Body Mass Index (28.9 ± 4.6 kg/m2, t(df) = 3.8(56), p = <.001) than fluctuating pacers (N = 31) (49.7 ± 19.5 yr), (24.9 ± 3.5 kg/m2). Even pacers also reported lower total minutes of self-reported physical activity per week (Median = 360 mins, IQR = 165-765 mins, Mann Whitney U = 276.5, p = .027) than fluctuating pacers (Median = 652.5 mins, IQR = 270-1435 mins). Even pacers had lower total minutes of accelerometer-derived physical activities per week (Median = 106 mins, IQR = 52-237 mins, U = 60, p = <.001) compared to fluctuating pacers (Median = 695.8 mins, IQR = 420-940 mins). Perceived activity pacing and fatigue were not different between the two groups (p= > .05). CONCLUSIONS: The comparison of the groups revealed differences in personal factors and physical activity, although they experienced similar fatigue levels. Those with an even pacing pattern showed lower physical activity levels, which may imply that pacing is used to regulate fatigue through lowering physical activity peaks as a reactive response to symptom occurrence. Future research could explore how pacing, physical activity, and fatigue management advice can contribute to increased physical activity.

Cross-Country Skiers With a Fast-Start Pacing Pattern Increase Time-Trial Performance by Use of a More Even Pacing Strategy.

To investigate whether skiers with a fast-start pacing pattern increase time-trial performance by use of a more even pacing strategy. Thirty-four skiers (∼17y, 16 male) performed an individual 7.5 (3 × 2.5)km free-technique race on snow with a self-selected pacing strategy (day 1). Based on the starting pace the first ∼2minutes (lap-1 first 600-m segment pace·7.5km pace-1), subjects were ranked into 2 groups: an intervention group with the fastest start pace (INT, n = 17) and a control group with a more conservative pace (CON, n = 17). On day 2, INT were instructed to reduce their start pace based on their average laps-1-to-3 segment pace from day 1, while CON were instructed to maintain their day 1 strategy. INT increased their time-trial performance more than CON from day 1 to day 2 (effect size; ES = 0.87, P < .05). From day 1 to day 2, INT slowed their start pace (mean ± 95% confidence interval; 7.7% ± 2.0%, ES = 2.00), with lowered heart rate (HR) (83% ± 2% to 81% ± 2% of HRmax) and 1 to 10 ratings of perceived exertion (5 ± 1 to 4 ± 1), but finished with a faster overall 7.5-km time (-1.9% ± 0.9%, ES = 0.99) (all P < .05). For CON, no change was found for starting pace (-0.7% ± 2.0%, P = .47), overall 7.5-km time (-0.2% ± 1.4%, ES = 0.02, P = .81), ratings of perceived exertion, or HR between days. No differences were found for end-ratings of perceived exertion (9 ± 1) or average HR between day 1 and 2 for either group. Skiers with a pronounced fast-start pattern benefit by using a more even pacing strategy to optimize time-trial distance skiing performance.

The Physiologic Mechanisms of Paced QRS Narrowing During Left Bundle Branch Pacing in Right Bundle Branch Block Patients.

Left bundle branch pacing (LBBP) is a physiological pacing technique that captures the left bundle branch (LBB) directly, causing the left ventricle (LV) to be excited earlier than the right ventricle (RV), resulting in a “iatrogenic” right bundle branch block (RBBB) pacing pattern. Several studies have recently shown that permanent LBBP can completely or partially narrow the wide QRS duration of the intrinsic RBBB in most patients with bradycardia, although the mechanisms by which this occurs has not been thoroughly investigated. This article presents a review of the LBBP in patients with intrinsic RBBB mentioned in current case reports and clinical studies, discussing the technique, possible mechanisms, future clinical explorations, and the feasibility of eliminating the interventricular dyssynchronization accompanied with LBBP.

A pace recognition method for exoskeleton wearers based on support vector machine-hidden Markov model

In order to improve the motion fluency and coordination of lower extremity exoskeleton robots and wearers, a pace recognition method of exoskeleton wearer is proposed base on inertial sensors. Firstly, the triaxial acceleration and triaxial angular velocity signals at the thigh and calf were collected by inertial sensors. Then the signal segment of 0.5 seconds before the current time was extracted by the time window method. And the Fourier transform coefficients in the frequency domain signal were used as eigenvalues. Then the support vector machine (SVM) and hidden Markov model (HMM) were combined as a classification model, which was trained and tested for pace recognition. Finally, the pace change rule and the human-machine interaction force were combined in this model and the current pace was predicted by the model. The experimental results showed that the pace intention of the lower extremity exoskeleton wearer could be effectively identified by the method proposed in this article. And the recognition rate of the seven pace patterns could reach 92.14%. It provides a new way for the smooth control of the exoskeleton.

World and European Rowing Medallists Pace With Smaller Variation Than Their Competitors.

Purpose: To establish the relation between pacing pattern and performance, within sex, and number of crew members, at the very highest performance level in World class rowing.Methods: Pacing profiles based on official 500 m split times in 106 A-finals with six contesting boat crews (n = 636 crews), in recent World (2017–2019) and European (2017–2021) championships, were analyzed. The coefficient of variation (CV) and sum of relative differences (SRD) of the split times, and normalized velocities in the four segments of the race, were compared between performance levels, that is, placement (1st–6th), and subgroups based on sex (female or male) and number of crew members (one, two, or four). Statistical tests and resulting p-values and effect sizes (Cohen's d) were used to assess differences between groups.Results: The pacing profiles of the medallists had smaller variation than those of the non-podium finishers (CV = 1.72% vs. CV = 2.00%; p = 4 × 10−7, d = 0.41). Compared to the non-podium finishers, the medallists had lower normalized velocities in the first and second segments of the race, slightly higher in the third segment and higher in the fourth segment. Female crews paced somewhat more evenly than male crews. No significant differences were found in the evenness of pacing profiles between singles, doubles/pairs and quads/fours. Analyses of SRD were overall consistent with analyses of CV.Conclusion: Medal winners in major rowing championships use a more even pacing strategy than their final competitors, which could imply that such a strategy is advantageous in rowing.

Champion Position Analysis in Short Track Speed Skating Competitions From 2007 to 2019.

Purpose: Short track speed skating is a racing sport with racing tactics are equally crucial to speed and technical skating skills. Therefore, to investigate the relationship between starting and finishing positions for elite skaters and subsequently, explore pacing patterns for champions are necessary.Methods: To investigate a pattern of effective tactical positioning strategy, Kendall’s tau-b correlations between starting and finishing position were calculated, with 500 m races having the most positive correlation (0.347, P < 0.05).Results: Furthermore, starting position distributions of winners in each round, as well as the fluctuations in champion starting positions across rounds were analyzed. Our findings showed that skaters on the first track were inclined to win the rounds in 500, 1,000, and 1,500 m (28, 28, and 22%, respectively), and the differences between starting and finishing positions for champions were minimized in semi-finals. Meanwhile, the pacing patterns were gaining more fluctuations by the increase of race distances for champions, as the average standard deviation of lap rankings equaled 0.90, 1.15, and 2.21 for 500, 1,000, and 1,500 m races, respectively.Conclusion: In conclusion, elite skaters should adopt flexible tactics at the lowest cost of energy consumption. The overall variability of lap ranking in long-distance races were distinctly higher than it in short distance.

Pacing Profiles of Middle-Distance Running World Records in Men and Women.

The aims of the current study were to compare the pacing patterns of all-time 800 m, 1500 m and mile running world records (WRs) and to determine whether differences exist between sexes, and if 800 m and 1500 m WRs were broken during championship or meet races. Overall and lap times for men and women’s 800 m, 1500 m, and mile WRs from World Athletics were collected when available and subsequently compared. A fast initial 200 m segment and a decrease in speed throughout was found during 800 m WRs. Accordingly, the first 200 m and 400 m were faster than the last 200 m and 400 m, respectively (p < 0.001, 0.77 ≤ ES ≤ 1.86). The first 400 m and 409 m for 1500 m and mile WRs, respectively, were faster than the second lap (p < 0.001, 0.74 ≤ ES ≤ 1.46). The third 400 m lap was slower than the last 300 m lap and 400 m lap for 1500 m and mile WRs, respectively (p < 0.001, 0.48 ≤ ES ≤ 1.09). No relevant sex-based differences in pacing strategy were found in any event. However, the first 409 m lap was faster than the last 400 m lap for men but not for women during mile WRs. Women achieved a greater % of WRs than men during championships (80% vs. 45.83% in the 800 m, and 63.63% vs. 31.58% in the 1500 m, respectively). In conclusion, positive, reverse J-shaped and U-shaped pacing profiles were used to break 800 m, men’s mile and 1500 m, and women’s mile WRs, respectively. WRs are more prone to be broken during championships by women than men.

South African speleothems reveal influence of high- and low-latitude forcing over the past 113.5 k.y.

Abstract Variation in δ18O and δ13C values in a speleothem from the Cango Caves in southernmost South Africa enable the construction of coherent regional composite records spanning the past 113,500 yr. Novel for the region in terms of both their length and detail, these records indicate environmental and climatic changes that both are consistent with records from the wider region and show a clear evolution from low- to high-latitude forcing dominance across the last glacial period. Prior to ca. 70 ka, the influence of direct low-latitude insolation forcing is expressed through increases in summer rainfall during austral summer insolation maxima. With the onset of Marine Isotope Stage 4, cooler global conditions and the development of high-latitude ice sheets appear to have supplanted direct insolation forcing as the dominant driver pacing patterns of environmental change, with records from the Southern and Northern Hemisphere tropics exhibiting a positive relationship until after the Last Glacial Maximum. These results highlight the complexity of South African climate change dynamics as a response to changing global boundary conditions and provide a critical reference for regional and global comparisons.

Exercise Intensity and Pacing Pattern During a Cross-Country Olympic Mountain Bike Race.

Objective: To examine the power profiles and pacing patterns in relation to critical power (CP) and maximal aerobic power (MAP) output during a cross-country Olympic (XCO) mountain bike race.Methods: Five male and two female national competitive XCO cyclists completed a UCI Cat. 1 XCO race. The races were 19 km and 23 km and contained five (female) and six (male) laps, respectively. Power output (PO) during the race was measured with the cyclists’ personal power meters. On two laboratory tests using their own bikes and power meters, CP and work capacity above CP (W') were calculated using three time trials of 12, 7, and 3 min, while MAP was established based on a 3-step submaximal test and the maximal oxygen uptake from the 7-min time trial.Results: Mean PO over the race duration (96 ± 7 min) corresponded to 76 ± 9% of CP and 63 ± 4% of MAP. 40 ± 8% of race time was spent with PO > CP, and the mean duration and magnitude of the bouts >CP was ~8 s and ~120% of CP. From the first to last lap, time >CP and accumulated W' per lap decreased with 9 ± 6% and 45 ± 17%, respectively. For single >CP bouts, mean magnitude and mean W' expended decreased by 25 ± 8% and 38 ± 15% from the first to the last lap, respectively. Number and duration of bouts did not change significantly between laps.Conclusion: The highly variable pacing pattern in XCO implies the need for rapid changes in metabolic power output, as a result of numerous separate short-lived >CP actions which decrease in magnitude in later laps, but with little lap-to-lap variation in number and duration.

Sustainability. The End of Finance as It Was

It is undeniable that sustainability has become one of the hottest discussion subjects nowadays. From a broad perspective, the ramifications of sustainability reach almost all of the social, political and economic territories. However, on many occasions, the lightness and superficiality with which the terms related to this matter are handled, make us think that it could be just a temporary fashion. We must not confuse ourselves. The truth is that we are witnessing profound changes in the socio-economic system that unveil a paradigm shift. If we set sustainability aside for a second, and we look from a pure socio-economic perspective, it becomes obvious that we are in the middle of an intergenerational wealth transfer of approximately 30 trillion dollars from the so-called baby boomers to their successors. And these successors - not just millennials, but people in their 30s to 40s - simply think about their economic decisions differently. Consequently, institutional investors have changed gears in their economic vision as well.It is the end of finance as it was. The consideration of ESG (Environmental, Social and Governance) factors into economic decisions represent not just a fashion but a new reality. A reality that represents a sizable challenge that, in many ways, comes along with plenty of controversy. In practice, it means the consideration of environmental, social and governance factors along with financial factors in the economic decision-making process. And this is a fundamental change for the financial and capital management world. The new paradigm confronts two main forces that can adopt different names, denominations or justifications: sustainability vs profitability, ESG vs financial performance, environment vs profit, etc. In sum, many economic operators may think that ESG factors could compromise financial performance. Is this reflection true or is it just an excuse for those anchored in certain patterns? This analysis will deep dive into the rational behind the current changes in the finance and capital markets to align its structures and business models to the new sustainable economy.10 keys explain the importance of sustainability in today’s finance world. These 10 macro trends are behind a profound transformation movement in the financial market setting up a new pace and new business patterns. It is the end of finance as it was.

Non-selective and selective His bundle pacing both preserve left ventricular activation time and pattern

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): British Heart Foundation Background: His bundle pacing can be achieved in two ways selective His bundle pacing, where the His bundle is captured alone, and non-selective His bundle pacing, where local myocardium is also captured resulting a pre-excited ECG appearance. We assessed the impact of this ventricular pre-excitation on left and right ventricular dys-synchrony. Methods We recruited patients who displayed both selective and non-selective His bundle pacing. We performed non-invasive epicardial electrical mapping to determine left and right ventricular activation times and patterns. Results In the primary analysis (n = 20, all patients), non-selective His bundle pacing did not prolong LVAT compared to select His bundle pacing by a pre-specified non-inferiority margin of 10ms (LVAT prolongation: -5.5ms, 95% confidence interval (CI): -0.6 to -10.4, non-inferiority p &amp;lt; 0.0001). Non-selective His bundle pacing did not prolong right ventricular activation time (4.3ms, 95%CI: -4.0 to 12.8, p = 0.296) but did prolong QRS duration (22.1ms, 95%CI: 11.8 to 32.4, p = 0.0003). In patients with narrow intrinsic QRS (n = 6), non-selective His bundle pacing preserved left ventricular activation time (-2.9ms, 95%CI: -9.7 to 4.0, p = 0.331) but prolonged QRS duration (31.4ms, 95%CI: 22.0 to 40.7, p = 0.0003) and mean right ventricular activation time (16.8ms, 95%CI: -5.3 to 38.9, p = 0.108) compared to selective His bundle pacing. Activation pattern of the left ventricular surface was unchanged between selective and non-selective His bundle pacing. Non-selective His bundle pacing produced early basal right ventricular activation, which was not observed with selective His bundle pacing. Conclusions Compared to selective His bundle pacing, local myocardial capture during non-selective His bundle pacing produces right ventricular pre-excitation resulting in prolongation of QRS duration. However, non-selective His bundle pacing preserves the left ventricular activation time and pattern of selective His bundle pacing. When choosing between selective and non-selective His bundle pacing, left ventricular dyssynchrony is not an important factor. Abstract Figure: Selective vs Non-Selective HBP

Activity Patterns and Functioning. A Contextual-Functional Approach to Pain Catastrophizing in Women with Fibromyalgia.

Background: The psychological flexibility model states that activity patterns are not deemed to be intrinsically functional or dysfunctional; it is considered that underlying factors, such as personal goals and contextual factors, are what will determine their effects on disability. Pain catastrophizing has frequently been associated with several important pain-related outcomes. Despite its recent conceptualization within affective–motivational approaches, its moderating role between activity patterns and dysfunction has not been analyzed. Methods: This study analyzes the moderating role of pain catastrophizing and its dimensions (Pain Catastrophizing Scale) between activity patterns (Activity Patterns Scale) and disease impact (Fibromyalgia Impact Questionnaire—Revised) in 491 women with fibromyalgia. Results: Activity avoidance (p < 0.001), excessive persistence (p < 0.001) and pacing (p < 0.01) patterns were positively associated with fibromyalgia impact. Helplessness shows a moderating role between pain avoidance (B = 0.100, t =2.30, p = 0.021, [0.01, 0.18]), excessive persistence (B = −0.09, t = −2.24, p = 0.02, [−0.18, −0.01]), pain persistence (B = −0.10, t = −2.04, p = 0.04, [−0.19, −0.004]) and functioning. Conclusion: Helplessness (within pain catastrophizing) is a relevant variable within psychological flexibility models applied to activity patterns. Specifically, pain avoidance is especially dysfunctional in patients with high helplessness. To improve excessive persistence and pain persistence, it is necessary to reduce helplessness before regulating activity patterns.

Are Pacing Patterns Really Based on Value Goals? Exploring the Contextual Role of Pain Acceptance and Pain Catastrophizing in Women with Fibromyalgia.

Pain catastrophizing and pain acceptance have been associated with functioning in fibromyalgia. In relation to activity patterns, pacing has been defined as a helpful pattern to regulate activities in the context of value-based goals, but results regarding whether it is adaptive or not are controversial. This study analyzes the moderating role of pain acceptance between pain catastrophizing and pacing in 231 women with fibromyalgia. Moderation analyses were conducted with model 1 from the PROCESS Macro version 3.4. The results showed a clear moderating effect of pain acceptance. At low levels of pain acceptance, catastrophizing and pacing patterns maintained significant and positive associations. However, at high levels of pain acceptance, pacing was independent of catastrophizing. Far from considering pacing patterns as functional or dysfunctional per se, our results suggest that women with low pain acceptance carry out pacing influenced by catastrophizing independently of their goal pursuit, while patients who accept their pain may use pacing as a regulatory mechanism according to their goals.