Physical Activity, Fitness, and Cardiac Autonomic Function among Adults Born Postterm.

Recent studies have suggested that adverse outcomes of postterm birth (≥42 completed weeks of gestation), including increased cardiometabolic risk factors, impaired glucose metabolism, and obesity, may extend into adulthood. We studied interconnected determinants of cardiovascular health, including physical activity (based on accelerometry for two weeks), muscular strength (handgrip strength), cardiorespiratory fitness (4-min step test), and cardiac autonomic function (heart rate recovery, heart rate variability, and baroreflex sensitivity) among 46-year-old adults from the Northern Finland Birth Cohort (NFBC) born postterm (n = 805) and at term (n = 2,645). Adults born postterm undertook vigorous-intensity physical activity 2.0 min/day (95% CI 0.4, 3.7) less than term-born adults when adjusted for sex, age, and maternal- and pregnancy-related covariates in multiple linear regression. Postterm birth was associated with reduced cardiorespiratory fitness based on a higher peak heart rate (2.1 bpm, 95% CI 0.9, 3.4) and slower heart rate recovery 30 s after the step test (-0.7 bpm, 95% CI -1.3, -0.1). Postterm birth was associated with lower vigorous-intensity physical activity and cardiorespiratory fitness and slower heart rate recovery in middle age. Our findings reinforce previous suggestions that postterm birth should be included as a perinatal risk factor for adult cardiometabolic disease.

The effects of a music intervention on the autonomic nervous system during recovery from strenuous exercise.

OBJECTIVE: To investigate the effect of music on heart rate recovery (HRR) and heart rate variability (HRV) after intense exertion. METHODS: Five hundred male students enrolled at Yongin University, Korea, underwent a cycling test to assess aerobic capacity; 180 students with equal scores were selected for a music intervention, which was conducted after vigorous exercise. The 180 participants were randomized into three music groups and a control group; the participants in each music group listened to music at three different tempos: slow (lento) (n = 45), moderate (moderato) (n = 45), and fast (allegretto) (n = 45). The control group did not listen to music (n = 45). After the test, data on cardiac recovery and HRV were gathered and modeled. RESULTS: The results revealed no significant variation in HRR and HRV indexes between the four cohorts (p > .05), and no significant differences were observed in the anaerobic power cycling indexes during strenuous exercise (p > .05). The music intervention had a significant impact on HR, low-frequency power (LF), high-frequency power (HF), normalized LF (LFnorm ), normalized HF (HFnorm ), and the LF/HF ratio during recovery (p < .05). CONCLUSION: After rigorous activity, listening to allegretto music improved HRR and restored HRV equilibrium, which is critical to preventing and minimizing arrhythmias and sudden cardiac death.

Joint association of sedentary time and physical activity with abnormal heart rate recovery in young and middle-aged adults.

BACKGROUND: Abnormal heart rate recovery (HRR), representing cardiac autonomic dysfunction, is an important predictor of cardiovascular disease. Prolonged sedentary time (ST) is associated with a slower HRR. However, it is not clear how much moderate-to-vigorous physical activity (MVPA) is required to mitigate the adverse effects of sedentary behavior on HRR in young and middle-aged adults. This study aimed to examine the joint association of ST and MVPA with abnormal HRR in this population. METHODS: A cross-sectional analysis was conducted on 1253 participants (aged 20-50 years, 67.8% male) from an observational study assessing cardiopulmonary fitness in Fujian Province, China. HRR measured via cardiopulmonary exercise tests on a treadmill was calculated as the difference between heart rate at peak exercise and 2 min after exercise. When the HRR was ≤ 42 beats·minute-1 within this time, it was considered abnormal. ST and MVPA were assessed by the IPAQ-LF. Individuals were classified as having a low sedentary time (LST [< 6 h·day-1]) or high sedentary time (HST [≥ 6 h·day-1]) and according to their MVPA level (low MVPA [0-149 min·week-1], medium MVPA [150-299 min·week-1], high MVPA [≥ 300 min·week-1]). Finally, six ST-MVPA groups were derived. Associations between ST-MVPA groups with abnormal HRR incidence were examined using logistic regression models. RESULTS: 53.1% of the young and middle-aged adults had less than 300 min of MVPA per week. In model 2, adjusted for possible confounders (e.g. age, sex, current smoking status, current alcohol consumption, sleep status, body mass index), HST was associated with higher odds of an abnormal HRR compared to LST (odds ratio (OR) = 1.473, 95% confidence interval (CI) = 1.172-1.852). Compared with the reference group (HST and low MVPA), the HST and high MVPA groups have a lower chance of abnormal HRR (OR, 95% CI = 0.553, 0.385-0.795). Compared with individuals with HST and low MVPA, regardless of whether MVPA is low, medium, or high, the odds of abnormal HRR in individuals with LST is significantly reduced (OR, 95% CI = 0.515, 0.308-0.857 for LST and low MVPA; OR, 95% CI = 0.558, 0.345-0.902 for LST and medium MVPA; OR, 95% CI = 0.476, 0.326-0.668 for LST and high MVPA). CONCLUSION: Higher amounts of MVPA appears to mitigate the increased odds of an abnormal HRR associated with HST for healthy young and middle-aged adults.

Correlation between Heart rate recovery and Left Atrial phasic functions evaluated by 2D speckle-tracking Echocardiography after Acute Myocardial infarction.

BACKGROUND: Heart rate recovery (HRR) in the exercise test is the index of cardiac autonomic system function and sympathovagal balance impaired in patients with myocardial infarction (MI). An instance is left atrial (LA) phasic function, which is impaired in such patients. In this study, we investigated the role of HRR in predicting LA phasic functions in patients with MI. METHODS: The present study recruited 144 consecutive patients with ST-elevation MI. A symptom-limited exercise test was performed about 5 weeks after MI, with echocardiography conducted just before the exercise test. The patients were divided into abnormal and normal HRR at 60 s (HRR60) and again into abnormal and normal HRR at 120 s (HRR120) after the exercise test. LA phasic functions, evaluated by 2D speckle-tracking echocardiography, were compared between the 2 groups. RESULTS: Patients with abnormal HRR120 had lower LA strain values and strain rates during the reservoir, conduit, and contraction phases, while those with abnormal HRR60 had lower LA strain values and strain rates during the reservoir and conduit phases. The differences were lost after adjustments for possible confounders, except for LA strain and strain rate during the conduit phase, in patients with abnormal HRR120. CONCLUSIONS: Abnormal HRR120 in the exercise test can independently predict decreased LA conduit function in patients with ST-elevation MI.

Does long-term exposure to air pollution suppress parasympathetic reactivation after incremental exercise among healthy males and females?

PURPOSE: As consequences of industrial processes, air pollution has led to increased cardiovascular diseases resulting in mortality. However, there are few pieces of evidence expressing physical fitness and gender impacts in such environments. Regarding long-term exposure to air pollution, this study aimed to determine the effect of physical fitness on post-exercise cardiac parasympathetic reactivation among healthy males and females. METHODS: 120 individuals (46 ± 5 years) participated and were categorized into two main groups (n = 60; EG, CG); (1) The experimental group included individuals living in an air-polluted environment; (2) The control group included the citizens of a clean air region; and two physical fitness status subgroups (n = 30; active vs. sedentary) across both sexes. The heart rate (HR) changes at different timing after performing an incremental exercise, and T30 were calculated as metrics of cardiac parasympathetic reactivation. RESULTS: The heart rate recovery values were substantially lower in EG in comparison to CG (p < 0.001) at different timing, while, T30 was significantly greater in residents of the air-polluted city compared to CG (p < 0.001). As for heart rate recovery at the 5th minute, the values were significantly lower in the steady-female group in comparison to the active females living in the air-polluted city (p < 0.01). CONCLUSION: Based on our findings, although physical fitness modifies the adverse impacts of long-term exposure to air pollution on post-exercise cardio-parasympathetic reactivation, it appears to parallel the acute/intermediate recovery of the thermoregulatory and vascular systems, among both sexes, it does not prevent them.

Prognostic value of the post-exercise heart rate recovery and BHDE-index in chronic obstructive pulmonary disease.

BACKGROUND: The BODE index, consisting of body mass index (B), airflow obstruction (O), dyspnea score (D), and exercise capacity (E), can predict outcomes in COPD. However, when spirometry was restricted to prevent cross-infection such as COVID-19 pandemic, a modified index would be needed. Because cardiovascular dysfunction is associated with poor clinical outcomes in COPD, we conducted a novel BHDE-index by replacing spirometry with post-exercise heart rate recovery (HRR, H) and evaluated its predictive performance in this observational study. METHODS: From January 2019 to December 2019, enrolled patients were analyzed as a derivation cohort for the setup of the model. This model was verified in another group of patients generated between January 2020 and December 2020, as the validation cohort. The post exercise HRR was defined as the difference of heart rate immediately after and 1 min after test cessation. RESULTS: A total of 447 patients with COPD were enrolled. Patients with abnormal HRR were older, with more severe airway obstruction, severe airway symptoms, faster resting heart rate, shorter 6-min walk distance and higher frequency of severe acute exacerbation in previous one year. The prediction performance of the BHDE-index for one-year severe COPD exacerbation was similar to that of the BODE-index in both the derivation and validation groups [area under the receiver operating characteristic curve (AUROC) 0.76 vs. 0.75, p = 0.369; AUROC 0.74 vs. 0.79, p = 0.05]. The prediction performance for 1 year mortality was also similar between BHDE-index and BODE-index in both cohorts [AUROC 0.80 vs. 0.77, p = 0.564; 0.76 vs. 0.70, p = 0.234]. Univariate and multivariate analyses also showed that the BHDE-index was an independent and important predictor of annual severe COPD exacerbation in the derivation and validation cohorts. CONCLUSIONS: The BHDE-index is a good and easy-to-perform prediction model for the risk of severe acute exacerbation and 1-year mortality in COPD wherever spirometry results are unavailable.

Cardiovascular fitness is associated with child adiposity at 5 years of age: findings from the ROLO longitudinal birth cohort study.

BACKGROUND: Cardiovascular fitness is strongly linked with metabolic risk; however, research is limited in preschool children. Although there is currently no simple validated measure of fitness in preschool children, heart rate recovery has been highlighted as an easily accessible and non-invasive predictor of cardiovascular risk in school-aged children and adolescents. We aimed to investigate whether heart rate recovery was associated with adiposity and blood pressure in 5-year-olds. STUDY DESIGN: This is a secondary analysis of 272 5-year-olds from the ROLO (Randomised cOntrol trial of LOw glycaemic index diet in pregnancy to prevent recurrence of macrosomia) Kids study. Three-minute step tests were completed by 272 participants to determine heart rate recovery duration. Body mass index (BMI), circumferences, skinfold thickness, heart rate, and blood pressure were collected. Independent t-tests, Mann-Whitney U, and Chi-square tests were used to compare participants. Linear regression models examined associations between heart rate recovery and child adiposity. Confounders included child sex, age at study visit, breastfeeding, and perceived effort in the step test. RESULTS: The median (IQR) age at the study visit was 5.13 (0.16) years. 16.2% (n = 44) had overweight and 4.4% (n = 12) had obesity based on their BMI centile. Boys had a quicker mean (SD) heart rate recovery after the step test than girls (112.5 (47.7) seconds vs. 128.8 (62.5) seconds, p = 0.02). Participants with a slower recovery time (> 105 s) had higher median (IQR) sum of skinfolds (35.5 (11.8) mm vs. 34.0 (10.0) mm, p = 0.02) and median (IQR) sum of subscapular and triceps skinfold (15.6 (4.4) mm vs. 14.4 (4.0) mm, p = 0.02) compared to participants with a quicker recovery time. After adjusting for confounders (child sex, age at study visit, breastfeeding, effort in the step test), linear regression analyses revealed heart rate recovery time after stepping was positively associated with sum of skinfolds (B = 0.034, 95% CI: 0.01, 0.06, p = 0.007). CONCLUSION: Child adiposity was positively associated with heart rate recovery time after the step test. A simple stepping test could be used as a non-invasive and inexpensive fitness tool in 5-year-olds. Additional research is needed to validate the ROLO Kids step test in preschool children.

Association of Postexercise Vagal Dysfunction With Protein-Energy Wasting and Noncardiovascular Outcomes in Patients Receiving Hemodialysis: A Retrospective Cohort Study.

OBJECTIVE: Postexercise vagal dysfunction is linked to noncardiovascular mortality in hemodialysis patients, but the mechanism is unknown. This study aimed to determine the association of cardiovagal neuropathy with systemic inflammation, protein-energy wasting, and noncardiovascular hospitalization. METHODS: This 2-center retrospective cohort study analyzed data from 280 hemodialysis patients who underwent exercise test. Patients were assessed for heart rate (HR) recovery (bpm) for 1 minute after exercise, a marker of vagal function, and were divided into 3 categories (Low: ≤ 6, Mid: 7-11, High: ≥ 12 bpm). We followed 1-year changes in the systemic inflammation-based prognostic score (Glasgow Prognostic Score [GPS]), body weight, and creatinine generation rate (CGR), an indicator of muscle mass, as well as 2-year hospitalization. RESULTS: The HR recovery category was associated with serum C-reactive protein and albumin levels and GPS. After 1 year, the low HR recovery category was associated with worsening in GPS (low, 0 [0-0.5]; mid, 0 [0-1]; high, 0 [0-0]), weight (low, 100.0 [96.1-102.5]; mid, 101.3 [98.9-105.0]; high, 100.5 [98.2-102.9]%), and CGR (low, 97.0 [88.5-111.4]; mid, 110.2 [90.9-124.8]; high, 106.2 [95.5-115.5]%), and the correlations with GPS and CGR remained consistent after adjusting for confounders such as exercise capacity and hospitalization during the follow-up period. There were 117 patients hospitalized. Compared to the high HR recovery category, the mid (hazard ratio: 1.8, 95% confidence interval [CI]: 1.1-3.1, P = .02) and low (hazard ratio: 2.4, 95% CI: 1.5-4.0, P = .001) categories were independently associated with an increased risk of all-cause hospitalization. For noncardiovascular disease hospitalization, the low HR recovery category was independently associated with increased risk of hospitalization (hazard ratio: 2.1, 95% CI: 1.2-3.7, P = .007). CONCLUSIONS: Vagal neuropathy in this population can contribute to adverse outcomes associated with systemic inflammation and protein-energy wasting.

Effectiveness of a 12-week tele-exercise training program on cardiorespiratory fitness and heart rate recovery in patients with cardiometabolic multimorbidity.

BACKGROUND: Exercise has positive impacts on cardiometabolic health. However, evidence regarding the effectiveness of tele-exercise training on cardiorespiratory fitness and heart rate recovery in patients with cardiometabolic multimorbidity remains limited. AIMS: The aim of this study was to assess whether an assumed increase in physical activity (PA) after a 12-week tele-exercise training program improved cardiorespiratory fitness and heart rate recovery of patients with cardiometabolic multimorbidity. METHODS: A parallel-group randomized controlled trial was conducted. Eligible patients with cardiometabolic multimorbidity (n = 83) were randomized 1:1 to either an experimental group (EG, received a 12-week tele-exercise training program with 3 sessions/week and 30 min/session and weekly remote monitoring for maintenance of exercise) or a control group (CG, usual care only). PA, cardiorespiratory fitness, and heart rate recovery were assessed at baseline and 12 weeks. Generalized estimating equations were used to examine the intervention effects via the interaction of time and group. RESULTS: Sixty-eight participants (81.9%) completed the study, and 83 were included in the intention-to-treat analysis. The EG with higher vigorous-intensity PA (ß = 714, p = .037), walking behavior (ß = 750, p = .0007), and total amount of PA (ß = 1748, p = .001) after the intervention had significantly elevated cardiorespiratory fitness, including VO2peak (ß = 3.9, p = .042), workload (ß = 17.9, p = .034), and anaerobic threshold (ß = 2.1, p = .041), and increased one-min heart rate recovery (ß = 5.3, p = .025), compared with the CG. LINKING EVIDENCE TO ACTION: A 12-week tele-exercise training program was effective for increased PA, elevated cardiorespiratory fitness, and improved heart rate recovery for patients with cardiometabolic multimorbidity. These findings highlight the feasibility of better delivering lifestyle interventions for cardiometabolic health management.

Heart rate recovery to assess fitness: comparison of different calculation methods in a large cross-sectional study.

We propose a cross-sectional study based on 980 maximal effort tests to quantify the effect of the calculation method of heart rate recovery (HRR) on its association with cardiorespiratory fitness (CRF). For five different time t0 after exercise cessation, HRR has been calculated as: the difference and the ratio between maximal measured heart rate and heart rate (HR) at t0HR at t0the decay time of an exponential decay encompassing the first t0 minutes of the HR recovery.The associations between HRR indices and CRF were estimated from generalized estimating equations stratified by gender and adjusted for age and body mass index. For HRR indices based on exponential regression, no significant association with CRF was found, whereas the other HRR indices are associated with CRF when t0 is at least 1 minute and is maximum for t0 = 2 minutes for females and t0 = 3 minutes for males.

Association of cardiac autonomic neuropathy assessed by heart rate response during exercise with intradialytic hypotension and mortality in hemodialysis patients.

The heart rate (HR) reflects the dynamic behavior of the autonomic nervous system, and HR profiles during the exercise test provide prognostic information. However, there are no reports of these factors in hemodialysis patients. Data from 256 patients (mean 68.8 years old) who underwent an exercise test were statistically analyzed. Patients were evaluated for the percent HR reserve from HR at peak exercise, HR recovery for one minute after peak exercise, and exercise capacity, as well as intradialytic hypotension (IDH). The prevalence of chronotropic incompetence (96.1%), defined as under 80% HR reserve, and abnormal HR recovery (60.5%), defined as under 12 beats, were very common. Eighty-four deaths occurred during the follow-up period (median, 3.8 years). A slow HR recovery under 7 beats was associated with IDH after adjustment (odds ratio 2.7, 95% confidence interval 1.1-6.4). HR recovery under 12 beats (hazard ratio over study period 5.1, 95% confidence interval 2.5-10.5), HR reserve under 26.2% (3.4, 1.7-6.8), and IDH (1.7, 1.1-2.8) were associated with all-cause mortality after adjustment. Considering the confounding of all three variables, only HR recovery under 12 beats remained associated with the all-cause and cause-specific mortality ("cardiovascular" and "non-cardiovascular"). This association was consistent even in subgroup analyses based on the presence of diabetes and cardiovascular disease. Thus, HR profiles during the exercise can reflect potential health conditions related to cardiac autonomic neuropathy in hemodialysis patients that affect IDH and their survival.

Evidence for impaired chronotropic responses to and recovery from 6-minute walk test in women with post-acute COVID-19 syndrome.

NEW FINDINGS: What is the central question of this study? Are chronotropic responses to a 6-minute walk test different in women with post-acute coronavirus disease 2019 (COVID-19) syndrome compared with control subjects? What is the main finding and its importance? Compared with control subjects, the increase in heart rate was attenuated and recovery delayed after a 6-minute walk test in participants after infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Women reporting specific symptoms at time of testing had greater impairments compared with control subjects and SARS-CoV-2 participants not actively experiencing these symptoms. Such alterations have potential to constrain not only exercise tolerance but also participation in free-living physical activity in women during post-acute recovery from COVID-19. ABSTRACT: The short-term cardiopulmonary manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are well defined. However, the implications of cardiopulmonary sequelae, persisting beyond acute illness, on physical function are largely unknown. Herein, we characterized heart rate responses to and recovery from a 6-minute walk test (6MWT) in women ∼3 months after mild-to-moderate SARS-CoV-2 infection compared with non-infected control subjects. Forty-five women (n = 29 SARS-CoV-2; n = 16 controls; age = 56 ± 11 years; body mass index = 25.8 ± 6.0 kg/m2 ) completed pulmonary function testing and a 6MWT. The SARS-CoV-2 participants demonstrated reduced total lung capacity (84 ± 8 vs. 93 ± 13%; P = 0.006), vital capacity (87 ± 10 vs. 93 ± 10%; P = 0.040), functional residual capacity (75 ± 16 vs. 88 ± 16%; P = 0.006) and residual volume (76 ± 18 vs. 93 ± 22%; P = 0.001) compared with control subjects. No between-group differences were observed in 6MWT distance (P = 0.194); however, the increase in heart rate with exertion was attenuated among SARS-CoV-2 participants compared with control subjects (+52 ± 20 vs. +65 ± 18 beats/min; P = 0.029). The decrease in heart rate was also delayed for minutes 1-5 of recovery among SARS-CoV-2 participants (all P < 0.05). Women reporting specific symptoms at the time of testing had greater impairments compared with control subjects and SARS-CoV-2 participants not actively experiencing these symptoms. Our findings provide evidence for marked differences in chronotropic responses to and recovery from a 6MWT in women several months after acute SARS-CoV-2 infection.

Effect of maturation on parasympathetic modulation during exercise and recovery.

OBJECTIVES: This study examined the effect of maturation on parasympathetic nervous system (PNS) response from rest to light- to moderate-intensity exercise and recovery from maximal exercise in pre- (n = 10; maturity offset = -3.0 ± 1.2 years; age = 10.1 ± 1.9 years), mid- (n = 9; maturity offset = -0.1 ± 0.6 years; age = 13.7 ± 1.0 years), and postpubertal (n = 10; maturity offset = 1.9 ± 0.6 years; age = 15.6 ± 1.2 years) boys and men (n = 10; age = 24.1 ± 2.0 years). DESIGN: Participants completed seated rest, light-intensity exercise (50% HRmax), and moderate-intensity exercise (65% HRmax). Following moderate-intensity exercise, intensity was ramped to elicit maximal HR and followed by 25 min of seated recovery. Log transformed values for root mean square of successive differences (lnRMSSD), high-frequency power (lnHF) and normalized HF power (lnHFnu) assessed PNS modulation during 3 min of rest, light-intensity exercise, moderate-intensity exercise, and 3-min epochs throughout recovery. RESULTS: During light-intensity exercise, lnRMSSD and lnHF were greater in prepubertal (lnRMSSD = 3.4 ± 0.3 ms; lnHF = 5.4 ± 0.7 ms2) compared to men (lnRMSSD = 2.8 ± 0.5 ms; lnHF = 4.0 ± 0.9 ms2). During moderate-intensity exercise, lnHF differed between prepubertal and men (2.8 ± 1.0 vs. 1.4 ± 1.0 ms2). During recovery, HRV variables were greater in prepubertal compared to postpubertal and men. CONCLUSIONS: Prepubertal boys have reduced PNS withdrawal during light-intensity exercise and greater PNS reactivation following exercise.

Heart Rate Recovery at 1 Min after Exercise Is a Marker of Disease Severity and Prognosis in Chronic Thromboembolic Pulmonary Hypertension.

BACKGROUND: Attenuated heart rate recovery at 1 min (HRR1) was demonstrated to correlate with poor prognosis in patients with pulmonary arterial hypertension, whereas its role in patients with chronic thromboembolic pulmonary hypertension (CTEPH) remains unclear. OBJECTIVES: The aim of this study was to investigate the correlations between HRR1 and functional status, echocardiography, hemodynamics, and prognosis of CTEPH. METHODS: We retrospectively enrolled patients with CTEPH who underwent right heart catheterization and cardiopulmonary exercise test between June 2014 to October 2020 in Fuwai hospital. The primary outcome was clinical worsening. Linear regression was performed to assess the association between HRR1 and established markers of CTEPH severity. Receiver operating characteristic curve analysis was performed to determine the optimal cutoff of HRR1. Cox regression models were used to assess the association between HRR1 and clinical worsening. RESULTS: A total of 211 patients with CTEPH were included in the study. After adjusting for confounders, HRR1 positively correlated with 6-min walk distance, mixed venous oxygen saturation, and peak oxygen consumption, and negatively correlated with NT-proBNP, pulmonary vascular resistance, and ventilatory equivalent of carbon dioxide. Compared with patients with HRR1 ≥16 beats, patients with HRR1 <16 beats had approximately a 3-fold risk of experiencing clinical worsening and the risk escalated with time. CONCLUSION: HRR1 could reflect disease severity and was independently associated with prognosis in patients with CTEPH.

Exercise Stress Electrocardiography Using the Two-Minute Jump Test in Children.

Although the treadmill and cycle ergometer are commonly used for exercise stress electrocardiography (ECG) testing, they are often difficult to perform with children. We herein evaluated the utility and safety of the 2-minute jump test (2MJT) as a simple, alternative exercise test. One hundred patients, including 60 male patients, with an average age at study commencement of 10.7±3.5 years (mean±standard deviation) and with no exercise restriction who underwent a cardiac check-up between November 2020 and March 2022 at the study center were included. After recording their resting ECG, they jumped for 2 minutes during ECG recording, and the change in heart rate (HR), ECG findings, and occurrence of adverse events were investigated. As a result, patients jumped 185±60 times in two minutes, and their HR increased from 76±13 beats/min at rest to 172±18 beats/min at peak during the test. Ninety (90%) patients attained the ideal target HR of > 150 beats/minute. During the recovery period after loading, five patients had abnormal ECG findings (ventricular extrasystoles, second-degree atrioventricular block, and atrial extrasystoles in two, two, and one patient, respectively) but completely resolved spontaneously within three minutes. Our findings suggested that the 2MJT is a useful and safe exercise test capable of inducing sufficient increase in HR in a short time in children.

Association between Circulating Adiponectin and Heart Rate Recovery in Women with Polycystic Ovarian Syndrome.

CONTEXT: Adiponectin (APN) is reported to be correlated closely with autonomic nervous function in different clinical settings. Heart rate recovery (HRR) is a noninvasive and readily obtainable indicator, which reflects the coordinated interplay between parasympathetic reactivation and sympathetic withdrawal. OBJECTIVE: This study aimed to investigate the relationship between serum APN and HRR in polycystic ovarian syndrome (PCOS) women. DESIGN: Eighty-nine PCOS women were enrolled and divided into two groups. Women with HRR values slower than 12 beats were defined as Blunted HRR Group. APN levels were compared between Blunted HRR Group and Normal HRR Group. Multivariate logistic regression analysis and multiple linear regression analysis were performed to determine which clinical variables were independently associated with HRR and APN levels, respectively. RESULTS: Twenty-three women were categorized into Blunted HRR Group, in which APN level was significantly lower than Normal HRR Group. Age, body mass index, hypertension, and APN were independent factors of attenuated HRR in PCOS women. Meanwhile, multiple linear regression analysis showed age, dyslipidemia, and homeostasis model assessment-insulin resistance (HOMA-IR) were closely associated with APN levels in PCOS women. CONCLUSIONS: Our findings suggested that decreased APN concentration was closely associated with HRR blunt in PCOS women. Further studies are needed to explore the underlying interactions between APN and autonomic nervous function.

The evaluation of the metabolic and autonomic predictors of cardiovascular diseases in relation to prostatic hyperplasia symptoms.

OBJECTIVES: High prevalence of cardiovascular diseases is present in benign prostatic hyperplasia patients. Risk prediction models were developed for early identification of these cardiovascular risks. We aimed to evaluate cardiovascular metabolic and autonomic predictors in relation to lower urinary tract symptoms' severity evaluated by the IPSS score. METHODS: This study included 318 healthy individuals recently diagnosed with BPH. Laboratory tests including metabolic, hormonal and inflammatory markers were recorded. The cardiovascular risk indices like the atherogenic index of plasma and the triglyceride glucose index were calculated. The heart rate recovery after graded exercise was calculated. RESULTS: There was a significant positive correlation between the IPSS score and both the atherogenic and the triglyceride glucose indices (r = 0.388, p < 0.01 and r = 0.109, p = 0.032, respectively). IPSS score was also significantly negatively correlated with heart rate recovery specially at the 3rd minute after exercise (r = -0.547, p < 0.01). On the other hand, the IPSS score had a significant positive correlation with the inflammatory markers and a significant negative correlation with serum testosterone levels. CONCLUSIONS: Our study results suggest the presence of a combination of hormonal and inflammatory changes in BPH patients affecting the severity of LUTS which is correlated with metabolic and autonomic parameters that can predict an increased risk of CVD (Tab. 3, Ref. 47).

Attenuated heart rate recovery is associated with higher arrhythmia recurrence and mortality following atrial fibrillation ablation.

AIMS: Heart rate recovery (HRR), the decrease in heart rate occurring immediately after exercise, is caused by the increase in vagal activity and sympathetic withdrawal occurring after exercise and is a powerful predictor of cardiovascular events and mortality. The extent to which it impacts outcomes of atrial fibrillation (AF) ablation has not previously been studied. The aim of this study is to investigate the association between attenuated HRR and outcomes following AF ablation. METHODS AND RESULTS: We studied 475 patients who underwent EST within 12 months of AF ablation. Patients were categorized into normal (>12 b.p.m.) and attenuated (≤12 b.p.m.) HRR groups. Our main outcomes of interest included arrhythmia recurrence and all-cause mortality. During a mean follow-up of 33 months, 43% of our study population experienced arrhythmia recurrence, 74% of those with an attenuated HRR, and 30% of those with a normal HRR (P < 0.0001). Death occurred in 9% of patients in the attenuated HRR group compared to 4% in the normal HRR cohort (P = 0.001). On multivariable models adjusting for cardiorespiratory fitness (CRF), medication use, left atrial size, ejection fraction, and renal function, attenuated HRR was predictive of increased arrhythmia recurrence (hazard ratio 2.54, 95% confidence interval 1.86-3.47, P < 0.0001). CONCLUSION: Heart rate recovery provides additional valuable prognostic information beyond CRF. An impaired HRR is associated with significantly higher rates of arrhythmia recurrence and death following AF ablation.

Chronic vagus nerve stimulation is associated with multi-year improvement in intrinsic heart rate recovery and left ventricular ejection fraction in ANTHEM-HF.

PURPOSE: Disturbed autonomic function is implicated in high mortality rates in heart failure patients. High-intensity vagus nerve stimulation therapy was shown to improve intrinsic heart rate recovery and left ventricular ejection fraction over a period of 1 year. Whether these beneficial effects are sustained across multiple years and are related to improved baroreceptor response was unknown. METHODS: All patients (n = 21) enrolled in the ANTHEM-HF clinical trial (NCT01823887, registered 4/3/2013) with 24 h ambulatory electrocardiograms at all time points and 54 normal subjects (PhysioNet database) were included. Intrinsic heart rate recovery, based on ~ 2000 spontaneous daily activity-induced heart rate acceleration/deceleration events per patient, was analyzed at screening and after 12, 24, and 36 months of chronic vagus nerve stimulation therapy (10 or 5 Hz, 250 µs pulse width, 18% duty cycle, maximum tolerable current amplitude). RESULTS: In response to chronic high-intensity vagus nerve stimulation (≥ 2.0 mA), intrinsic heart rate recovery (all time points, p < 0.0001), heart rate turbulence slope, an indicator of baroreceptor reflex gain (all, p ≤ 0.02), and left ventricular ejection fraction (all, p ≤ 0.04) were improved over screening at 12, 24, and 36 months. Intrinsic heart rate recovery and heart rate turbulence slope were inversely correlated at both screening (r = 0.67, p < 0.002) and 36 months (r = 0.78, p < 0.005). CONCLUSION: This non-randomized study provides evidence of an association between improvement in intrinsic heart rate recovery and left ventricular ejection fraction during high-intensity vagus nerve stimulation for a period of ≥ 3 years. Correlated favorable effects on heart rate turbulence slope implicate enhanced baroreceptor function in response to chronic, continuously cyclic vagus nerve stimulation as a physiologic mechanism.

Post-exercise heart rate recovery and its speed are associated with cardiac autonomic responsiveness following orthostatic stress test in men.

Objective: The present study sought to expand upon prior investigations of the relationship between the post-exercise heart rate recovery (HRR) and the cardiac autonomic responsiveness after orthostatic stress test.Method: HRR at the 1st, 3rd, and 5th min after maximal exercise test were correlated with relative change (Δ%) of time-domain (CV, pNN50, and rMSSD) and frequency-domain (TP, LF, HF, and LF/HF ratio) indices of heart rate variability (HRV) after active orthostatic test in 46 healthy men. Statistical analysis employed non-parametric tests with a p-value set at 5%.Results: HRR at 1st min correlated with Δ%pNN50 (rs:0.36 - p = .02). In the 3rd and 5th min, these measures correlated with Δ%pNN50, Δ%rMSSD, Δ%CV, Δ%TP, and Δ%HF indices (rs:0.33, 0.59 - p ≤ .05). Coefficient of HRR at the 1st min correlated with Δ%pNN50, Δ%rMSSD, and Δ%HF (rs:0.28, 0.45 - p ≤ .05). The 3rd and 5th min showed correlation with Δ%pNN50, Δ%rMSSD, Δ%HF, Δ%CV, and Δ%TP (rs:0.37, 0.64 - p ≤ .05). No correlation was found with indices combined sympathetic-parasympathetic modulation and HRR. After the sample was divided into high and low parasympathetic responsiveness subgroups after the orthostatic test, faster HRR was associated with the degree of parasympathetic responsiveness (reduction) following postural change (p ≤ .05).Conclusion: HRR throughout the 1st to 5th min is positively correlated with parasympathetic responsiveness and overall cardiac autonomic modulation of HRV after the orthostatic stress test, and faster HRR is positively correlated with the relative degree of parasympathetic responsiveness after the active postural change at rest in healthy men.