Study of cardiac autonomic control and physical fitness in martial artists

OBJECTIVES: To study the effect of Kungfu training on cardiac autonomic status and physical fitness by comparing Kungfu trained subjects with control subjects matched for age, BMI and physical activity level. MATERIALS AND METHODS: Twenty Kungfu trained subjects and twenty matched control subjects were rested in supine position for twenty minutes. ECG and respiration data was acquired for five minutes after this, to obtain short-term heart rate variability parameters and other resting parameters. Standard cardiac autonomic tests were done. A maximal treadmill test was done and exercise duration, heart rate at maximal intensity and heart rate during recovery was measured and further analyzed to obtain recovery heart rates and time constants of recovery. All parameters were correlated with duration of Kungfu training. Analysis was done using SPSS software and suitable statistical tests were done. RESULTS: Subjects with Kungfu training had greater total heart rate variability as denoted by greater SDNN similar physical activity levels. This augmented cardiac autonomic control observed in Kungfu subjects may be attributable to the regular practice of ‘breath out maneuvers’, which form an intrinsic part of the exercise protocol of Kungfu training. Kungfu training allowed the subject to do similar quantum of work at a lower heart rate than controls, as evidenced by the lower heart rate in the Kungfu group at similar maximal work intensities reached by both groups. With increased duration of Kungfu training there was significant decrease in the maximal heart rate achieved with maximal exercise and the absolute heart rate at thirty seconds after stopping maximal exercise, in the martial artists his finding may simply be a reflection of the positive effect of longer duration of training on the work capacity and max of martial artists. SUMMARY AND CONCLUSIONS: Higher physical fitness appears to prolong life. To attain, maintain and improve fitness, one mode of physical activity used is exercise. Exercise consists of planned, structured, and repetitive bodily movement. Martial arts are methods of combat that have been altered into exercises. Kung Fu is a generic term used for Chinese martial arts. Kungfu is a unique which incorporates a mixed anaerobic and aerobic exercise regimen which is combined with breathing exercises and meditation. No studies have been done on the effect of Kung Fu training on cardiac autonomic function. This study looked at the effect of Kungfu training on cardiac autonomic status and physical fitness. The cardiac autonomic effects of endurance and strength training have been studied separately and documented. But there are no studies on combined aerobic and anaerobic training programs on cardiac autonomic status. Further, breathing exercises and meditation have been shown to affect cardiac autonomic status by lowering heart rate, modifying heart rate variability and decreasing blood pressure. Kung Fu involves aerobic and anaerobic training, along with meditation and breathing exercises. There are no studies reporting the combined effects of all these maneuvers on physical fitness and cardiac autonomic control. Twenty Martial artists who have practiced Kungfu for over a year were recruited and compared with twenty normal subjects of similar age, BMI and physical activity. Cardiac autonomic status and fitness level was compared between these groups. The cardiac autonomic function tests administered were heart rate variability analysis, deep breathing test, orthostatic challenge test, Valsalva maneuver and maximal hand grip test. The tests were conducted as per standardized published protocols. Standard indices were calculated from these tests and compared. The resting heart rate, resting blood pressure and rate pressure product were also obtained. This was followed by a maximal treadmill test. A maximal exercise test was used to estimate O2 max indirectly. A fixed ramp protocol was used in a motor driven treadmill to administer a maximal test. Immediately after exercise, the subject rested in the supine position, during the period of recovery. The maximal heart rate achieved with maximal exercise (HRmax) and absolute heart rates at different points of recovery was obtained. The heart rate recovery (HRR) at a given point of time was computed by subtracting the absolute heart rate at that point of time from the HRmax. HRR is an index of physical fitness and a predictor of O2 max. (24) The ratio of H max to resting heart rate and total exercise duration was also used as predictors of O2 max. The work intensity at maximal exercise was also calculated and compared. The recovery heart rate decay was analyzed and it fitted well with double exponential functions. Two time constants were derived. The lower time constant was arbitrarily selected to be the parasympathetic reactivation time constant and the higher one was selected to be the sympathetic withdrawal time constant. These time constants were compared between the two groups. The effect of duration of Kungfu training on the various autonomic parameters was analyzed. Tests revealed significantly increased SDNN and RMSSD parameters of short-term heart rate variability in Kungfu trained subjects showing improved overall autonomic modulations and vagal modulations when compared to controls,. The maximal heart rate reached with maximal exercise was significantly less in Kungfu group. With increased duration of Kungfu training there was significant decrease in the maximal heart rate achieved with maximal exercise and the absolute heart rate thirty seconds after stopping maximal exercise, in the martial artists. This finding may simply be a reflection of the positive effect of longer duration of training on the work capacity and O max of martial artists. Kungfu is a unique form of exercise training which incorporates aerobic exercises, anaerobic exercises, breathing exercises and meditation. Kungfu training improved overall heart rate variability and vagal modulations and allowed the subject to do similar quantum of work at a lower heart rate than controls, as evidenced by the lower heart rate in the Kungfu group at similar maximal work intensities reached by both groups

Two Cheers For Diversity: An Experimental Study Of Micro-level Heterogeneity In Problemistic Search

In this paper, we argue for an expanded view of problemistic search. Recent behavioral theory research suggests that individual search preferences influence problemistic search. We draw on this to challenge the view of problemistic search as a centrally directed organizational process that proceeds sequentially from local to distant search. We argue that search activities in organizations are heterogeneous – some individuals will first engage in local search while others may move directly to distant search. We propose that problemistic search at the macroorganizational level is therefore the result of a mix of local and distant search activities at the micro-level that shifts towards distant search in response to negative performance evaluation. We test this idea in a laboratory experiment using a repetitive task and performance feedback

The TeleStroke Mimic (TM)‐Score: A Prediction Rule for Identifying Stroke Mimics Evaluated in a Telestroke Network

Background: Up to 30% of acute stroke evaluations are deemed stroke mimics (SM). As telestroke consultation expands across the world, increasing numbers of SM patients are likely being evaluated via Telestroke. We developed a model to prospectively identify ischemic SMs during Telestroke evaluation. Methods and Results: We analyzed 829 consecutive patients from January 2004 to April 2013 in our internal New England–based Partners TeleStroke Network for a derivation cohort, and 332 cases for internal validation. External validation was performed on 226 cases from January 2008 to August 2012 in the Partners National TeleStroke Network. A predictive score was developed using stepwise logistic regression, and its performance was assessed using receiver‐operating characteristic (ROC) curve analysis. There were 23% SM in the derivation, 24% in the internal, and 22% in external validation cohorts based on final clinical diagnosis. Compared to those with ischemic cerebrovascular disease (iCVD), SM had lower mean age, fewer vascular risk factors, more frequent prior seizure, and a different profile of presenting symptoms. The TeleStroke Mimic Score (TM‐Score) was based on factors independently associated with SM status including age, medical history (atrial fibrillation, hypertension, seizures), facial weakness, and National Institutes of Health Stroke Scale >14. The TM‐Score performed well on ROC curve analysis (derivation cohort AUC=0.75, internal validation AUC=0.71, external validation AUC=0.77). Conclusions: SMs differ substantially from their iCVD counterparts in their vascular risk profiles and other characteristics. Decision‐support tools based on predictive models, such as our TM Score, may help clinicians consider alternate diagnosis and potentially detect SMs during complex, time‐critical telestroke evaluations

Accuracy of the Veterans Health Administration COVID-19 (VACO) Index for predicting short-term mortality among 1,307 Yale New Haven Hospital inpatients and 427,224 Medicare patients

AbstractBackgroundThe Veterans Health Administration COVID-19 (VACO) Index incorporates age, sex, and pre-existing comorbidity diagnoses readily available in the electronic health record (EHR) to predict 30-day all-cause mortality in both inpatients and outpatients infected with SARS-CoV-2. We examined the performance of the Index using data from Yale New Haven Hospital (YNHH) and national Medicare data overall, over time, and within important patient subgroups.Methods and findingsWith measures and weights previously derived and validated in a national Veterans Healthcare Administration (VA) sample, we evaluated the accuracy of the VACO Index for estimating inpatient (YNHH) and both inpatient and outpatient mortality (Medicare) using area under the receiver operating characteristic curve (AUC) and comparisons of predicted versus observed mortality by decile (calibration plots). The VACO Index demonstrated similar discrimination and calibration in both settings, over time, and among important patient subgroups including women, Blacks, Hispanics, Asians, and Native Americans. In sensitivity analyses, we allowed component variables to be re-weighted in the validation datasets and found that weights were largely consistent with those determined in VA data. Supplementing the VACO Index with body mass index and race/ethnicity had no effect on discrimination.ConclusionAmong COVID-19 positive individuals, the VACO Index accurately estimates risk of short-term mortality among a wide variety of patients. While it modestly over-estimates risk in recent intervals, the Index consistently identifies those at greatest relative risk. The VACO Index could identify individuals who should continue practicing social distancing, help determine who should be prioritized for vaccination, and among outpatients who test positive for SARS-CoV-2, indicate who should receive greater clinical attention or monoclonal antibodies.</jats:sec

Accuracy of the Veterans Health Administration COVID-19 (VACO) Index for predicting short-term mortality among 1307 US academic medical centre inpatients and 427 224 US Medicare patients.

BACKGROUND: The Veterans Health Administration COVID-19 (VACO) Index predicts 30-day all-cause mortality in patients with COVID-19 using age, sex and pre-existing comorbidity diagnoses. The VACO Index was initially developed and validated in a nationwide cohort of US veterans-we now assess its accuracy in an academic medical centre and a nationwide US Medicare cohort. METHODS: With measures and weights previously derived and validated in US national Veterans Health Administration (VA) inpatients and outpatients (n=13 323), we evaluated the accuracy of the VACO Index for estimating 30-day all-cause mortality using area under the receiver operating characteristic curve (AUC) and calibration plots of predicted versus observed mortality in inpatients at a single US academic medical centre (n=1307) and in Medicare inpatients and outpatients aged 65+ (n=427 224). RESULTS: 30-day mortality varied by data source: VA 8.5%, academic medical centre 17.5%, Medicare 16.0%. The VACO Index demonstrated similar discrimination in VA (AUC=0.82) and academic medical centre inpatient population (AUC=0.80), and when restricted to patients aged 65+ in VA (AUC=0.69) and Medicare inpatient and outpatient data (AUC=0.67). The Index modestly overestimated risk in VA and Medicare data and underestimated risk in Yale New Haven Hospital data. CONCLUSIONS: The VACO Index estimates risk of short-term mortality across a wide variety of patients with COVID-19 using data available prior to or at the time of diagnosis. The VACO Index could help inform primary and booster vaccination prioritisation, and indicate who among outpatients testing positive for SARS-CoV-2 should receive greater clinical attention or scarce treatments

How do supply- and demand-side interventions influence equity in healthcare utilisation? Evidence from maternal healthcare in Senegal

The launch of the Millennium Development Goals in 2000, followed by the Sustainable Development Goals in 2015, and the increasing focus on achieving universal health coverage has led to numerous interventions on both supply- and demand-sides of health systems in low- and middle-income countries. While tremendous progress has been achieved, inequities in access to healthcare persist, leading to calls for a closer examination of the equity implications of these interventions. This paper examines the equity implications of two such interventions in the context of maternal healthcare in Senegal. The first intervention on the supply-side focuses on improving the availability of maternal health services while the second intervention, on the demand-side, abolished user fees for facility deliveries. Using three rounds of Demographic Health Surveys covering the period 1992 to 2010 and employing three measures of socioeconomic status (SES) based on household wealth, mothers' education and rural/urban residence – we find that although both interventions increase utilisation of maternal health services, the rich benefit more from the supply-side intervention, thereby increasing inequity, while the poor benefit more from the demand-side intervention i.e. reducing inequity. Both interventions positively influence facility deliveries in rural areas although the increase in facility deliveries after the demand-side intervention is more than the increase after the supply-side intervention. There is no significant difference in utilisation based on mothers’ education. Since people from different SES categories are likely to respond differently to interventions on the supply- and demand-side of the health system, policymakers involved in the design of health programmes should pay closer attention to concerns of inequity and elite capture that may unintentionally result from these interventions

Rapid synchronous type 1 IFN and virus-specific T cell responses characterize first wave non-severe SARS-CoV-2 infections

Effective control of SARS-CoV-2 infection on primary exposure may reveal correlates of protective immunity to future variants, but we lack insights into immune responses before or at the time virus is first detected. We use blood transcriptomics, multiparameter flow cytometry, and T cell receptor (TCR) sequencing spanning the time of incident non-severe infection in unvaccinated virus-naive individuals to identify rapid type 1 interferon (IFN) responses common to other acute respiratory viruses and cell proliferation responses that discriminate SARS-CoV-2 from other viruses. These peak by the time the virus is first detected and sometimes precede virus detection. Cell proliferation is most evident in CD8 T cells and associated with specific expansion of SARS-CoV-2-reactive TCRs, in contrast to virus-specific antibodies, which lag by 1–2 weeks. Our data support a protective role for early type 1 IFN and CD8 T cell responses, with implications for development of universal T cell vaccines

Large clones of pre-existing T cells drive early immunity against SARS-COV-2 and LCMV infection

T cell responses precede antibody and may provide early control of infection. We analyzed the clonal basis of this rapid response following SARS-COV-2 infection. We applied T cell receptor (TCR) sequencing to define the trajectories of individual T cell clones immediately. In SARS-COV-2 PCR+ individuals, a wave of TCRs strongly but transiently expand, frequently peaking the same week as the first positive PCR test. These expanding TCR CDR3s were enriched for sequences functionally annotated as SARS-COV-2 specific. Epitopes recognized by the expanding TCRs were highly conserved between SARS-COV-2 strains but not with circulating human coronaviruses. Many expanding CDR3s were present at high frequency in pre-pandemic repertoires. Early response TCRs specific for lymphocytic choriomeningitis virus epitopes were also found at high frequency in the preinfection naive repertoire. High-frequency naive precursors may allow the T cell response to respond rapidly during the crucial early phases of acute viral infection