The Fontan Udenafil Exercise Longitudinal Trial: Subgroup Analysis.

The Pediatric Heart Network's Fontan Udenafil Exercise Longitudinal (FUEL) Trial (Mezzion Pharma Co. Ltd., NCT02741115) demonstrated improvements in some measures of exercise capacity and in the myocardial performance index following 6 months of treatment with udenafil (87.5 mg twice daily). In this post hoc analysis, we evaluate whether subgroups within the population experienced a differential effect on exercise performance in response to treatment. The effect of udenafil on exercise was evaluated within subgroups defined by baseline characteristics, including peak oxygen consumption (VO2), serum brain-type natriuretic peptide level, weight, race, gender, and ventricular morphology. Differences among subgroups were evaluated using ANCOVA modeling with fixed factors for treatment arm and subgroup and the interaction between treatment arm and subgroup. Within-subgroup analyses demonstrated trends toward quantitative improvements in peak VO2, work rate at the ventilatory anaerobic threshold (VAT), VO2 at VAT, and ventilatory efficiency (VE/VCO2) for those randomized to udenafil compared to placebo in nearly all subgroups. There was no identified differential response to udenafil based on baseline peak VO2, baseline BNP level, weight, race and ethnicity, gender, or ventricular morphology, although participants in the lowest tertile of baseline peak VO2 trended toward larger improvements. The absence of a differential response across subgroups in response to treatment with udenafil suggests that the treatment benefit may not be restricted to specific sub-populations. Further work is warranted to confirm the potential benefit of udenafil and to evaluate the long-term tolerability and safety of treatment and to determine the impact of udenafil on the development of other morbidities related to the Fontan circulation.Trial Registration NCT0274115.

Exercise Stress Echocardiography in Kawasaki Disease Patients with Coronary Aneurysms.

The most significant sequelae of Kawasaki disease (KD) are coronary artery aneurysms, which can lead to risk of future myocardial ischemia. Exercise stress echocardiography allows for non-invasive assessment of myocardial dysfunction. We reviewed our single center experience with exercise stress echocardiography in patients with previous history of KD with coronary aneurysms. We reviewed the records of 53 KD patients who underwent exercise stress echocardiography from 2000 to 2020. Abnormal stress echocardiograms were defined as those showing no increase in biventricular systolic function post-exercise or regional wall motion abnormalities. Computed tomography angiography and cardiac magnetic resonance imaging were reviewed for patients with abnormal stress echocardiograms. Clinical data were reviewed and correlated with stress echocardiogram results. Of the 53 patients, three (5.7%) had an abnormal exercise stress echocardiogram. All three patients were classified as AHA Risk Level 4 or 5 by coronary Z-score (internal dimension normalized for body surface area) and were confirmed to have coronary aneurysms, stenosis, or myocardial tissue perfusion defects on advanced cardiac imaging that could account for the results seen on stress echocardiogram. Exercise stress echocardiography detected signs of myocardial ischemia in a subset of high-risk patients with Kawasaki disease and coronary aneurysms and may be considered as a useful screening tool for this complex patient cohort.

Abnormal pulmonary perfusion heterogeneity in patients with Fontan circulation and pulmonary arterial hypertension.

KEY POINTS: The distribution of pulmonary perfusion is affected by gravity, vascular branching structure and active regulatory mechanisms, which may be disrupted by cardiopulmonary disease, but this is not well studied, particularly in rare conditions. We evaluated pulmonary perfusion in patients who had undergone Fontan procedure, patients with pulmonary arterial hypertension (PAH) and two groups of controls using a proton magnetic resonance imaging technique, arterial spin labelling to measure perfusion. Heterogeneity was assessed by the relative dispersion (SD/mean) and gravitational gradients. Gravitational gradients were similar between all groups, but heterogeneity was significantly increased in both patient groups compared to controls and persisted after removing contributions from large blood vessels and gravitational gradients. Patients with Fontan physiology and patients with PAH have increased pulmonary perfusion heterogeneity that is not explainable by differences in mean perfusion, gravitational gradients, or large vessel anatomy. This probably reflects vascular remodelling in PAH and possibly in Fontan physiology. ABSTRACT: Many factors affect the distribution of pulmonary perfusion, which may be disrupted by cardiopulmonary disease, but this is not well studied, particularly in rare conditions. An example is following the Fontan procedure, where pulmonary perfusion is passive, and heterogeneity may be increased because of the underlying pathophysiology leading to Fontan palliation, remodelling, or increased gravitational gradients from low flow. Another is pulmonary arterial hypertension (PAH), where gravitational gradients may be reduced secondary to high pressures, but remodelling may increase perfusion heterogeneity. We evaluated regional pulmonary perfusion in Fontan patients (n = 5), healthy young controls (Fontan control, n = 5), patients with PAH (n = 6) and healthy older controls (PAH control) using proton magnetic resonance imaging. Regional perfusion was measured using arterial spin labelling. Heterogeneity was assessed by the relative dispersion (SD/mean) and gravitational gradients. Mean perfusion was similar (Fontan = 2.50 ± 1.02 ml min-1  ml-1 ; Fontan control = 3.09 ± 0.58, PAH = 3.63 ± 1.95; PAH control = 3.98 ± 0.91, P = 0.26), and the slopes of gravitational gradients were not different (Fontan = -0.23 ± 0.09 ml min-1  ml-1  cm-1 ; Fontan control = -0.29 ± 0.23, PAH = -0.27 ± 0.09, PAH control = -0.25 ± 0.18, P = 0.91) between groups. Perfusion relative dispersion was greater in both Fontan and PAH than controls (Fontan = 1.46 ± 0.18; Fontan control = 0.99 ± 0.21, P = 0.005; PAH = 1.22 ± 0.27, PAH control = 0.91 ± 0.12, P = 0.02) but similar between patient groups (P = 0.13). These findings persisted after removing contributions from large blood vessels and gravitational gradients (all P < 0.05). We conclude that patients with Fontan physiology and PAH have increased pulmonary perfusion heterogeneity that is not explained by differences in mean perfusion, gravitational gradients, or large vessel anatomy. This probably reflects the effects of remodelling in PAH and possibly in Fontan physiology.

Face Masks and the Cardiorespiratory Response to Physical Activity in Health and Disease.

To minimize transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the novel coronavirus responsible for coronavirus disease (COVID-19), the U.S. Centers for Disease Control and Prevention and the World Health Organization recommend wearing face masks in public. Some have expressed concern that these may affect the cardiopulmonary system by increasing the work of breathing, altering pulmonary gas exchange and increasing dyspnea, especially during physical activity. These concerns have been derived largely from studies evaluating devices intentionally designed to severely affect respiratory mechanics and gas exchange. We review the literature on the effects of various face masks and respirators on the respiratory system during physical activity using data from several models: cloth face coverings and surgical masks, N95 respirators, industrial respirators, and applied highly resistive or high-dead space respiratory loads. Overall, the available data suggest that although dyspnea may be increased and alter perceived effort with activity, the effects on work of breathing, blood gases, and other physiological parameters imposed by face masks during physical activity are small, often too small to be detected, even during very heavy exercise. There is no current evidence to support sex-based or age-based differences in the physiological responses to exercise while wearing a face mask. Although the available data suggest that negative effects of using cloth or surgical face masks during physical activity in healthy individuals are negligible and unlikely to impact exercise tolerance significantly, for some individuals with severe cardiopulmonary disease, any added resistance and/or minor changes in blood gases may evoke considerably more dyspnea and, thus, affect exercise capacity.

Results of the FUEL Trial.

BACKGROUND: The Fontan operation creates a total cavopulmonary connection, a circulation in which the importance of pulmonary vascular resistance is magnified. Over time, this circulation leads to deterioration of cardiovascular efficiency associated with a decline in exercise performance. Rigorous clinical trials aimed at improving physiology and guiding pharmacotherapy are lacking. METHODS: The FUEL trial (Fontan Udenafil Exercise Longitudinal) was a phase III clinical trial conducted at 30 centers. Participants were randomly assigned udenafil, 87.5 mg twice daily, or placebo in a 1:1 ratio. The primary outcome was the between-group difference in change in oxygen consumption at peak exercise. Secondary outcomes included between-group differences in changes in submaximal exercise at the ventilatory anaerobic threshold, the myocardial performance index, the natural log of the reactive hyperemia index, and serum brain-type natriuretic peptide. RESULTS: Between 2017 and 2019, 30 clinical sites in North America and the Republic of Korea randomly assigned 400 participants with Fontan physiology. The mean age at randomization was 15.5±2 years; 60% of participants were male, and 81% were white. All 400 participants were included in the primary analysis with imputation of the 26-week end point for 21 participants with missing data (11 randomly assigned to udenafil and 10 to placebo). Among randomly assigned participants, peak oxygen consumption increased by 44±245 mL/min (2.8%) in the udenafil group and declined by 3.7±228 mL/min (-0.2%) in the placebo group (P=0.071). Analysis at ventilatory anaerobic threshold demonstrated improvements in the udenafil group versus the placebo group in oxygen consumption (+33±185 [3.2%] versus -9±193 [-0.9%] mL/min, P=0.012), ventilatory equivalents of carbon dioxide (-0.8 versus -0.06, P=0.014), and work rate (+3.8 versus +0.34 W, P=0.021). There was no difference in change of myocardial performance index, the natural log of the reactive hyperemia index, or serum brain-type natriuretic peptide level. CONCLUSIONS: In the FUEL trial, treatment with udenafil (87.5 mg twice daily) was not associated with an improvement in oxygen consumption at peak exercise but was associated with improvements in multiple measures of exercise performance at the ventilatory anaerobic threshold. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02741115.

Cardiovascular and Musculoskeletal Assessment of Elite US Volleyball Players.

OBJECTIVE: The aim of this study was to characterize the cardiovascular and musculoskeletal systems of elite volleyball players, including aortic dimensions. Previous studies have shown that the upper limit of normal aortic sinus diameter for male and female athletes is 4 and 3.4 cm, respectively. DESIGN: Cross-sectional analysis. SETTING: United States Olympic Volleyball Training Facility and Rady Children's Hospital San Diego. PARTICIPANTS: Seventy (37 male) members of the US national volleyball team. MAIN OUTCOME MEASURES: Athletes underwent evaluation that included medical and family histories, targeted physical examinations specifically focusing on abnormalities present in Marfan syndrome (MFS), and transthoracic echocardiograms. Cardiac chamber and great artery size, valve function, and coronary artery origins were assessed. RESULTS: Three male athletes (8%) had an aortic sinus diameter ≥4 cm, one of whom also had an ascending aorta >4 cm. Two female athletes (6%) had aortic sinus diameter ≥3.4 cm, and another had an ascending aorta of 3.4 cm. There were no other intracardiac or arterial abnormalities. Individual musculoskeletal characteristics of MFS were common among the athletes but not more frequent or numerous in those with aortic dilation. CONCLUSIONS: The prevalence of aortic root dilation in this population of athletes was higher than what has previously been reported in other similar populations. Further study is needed to determine whether these represent pathological changes or normal variations in tall athletes. CLINICAL RELEVANCE: This study adds to the existing knowledge base of athlete's heart, with specific attention to aortic dimensions in elite volleyball players. The data are relevant to similar athletes' medical care and to preparticipation cardiac screening in general.

The heterogeneity of regional specific ventilation is unchanged following heavy exercise in athletes.

Heavy exercise increases ventilation-perfusion mismatch and decreases pulmonary gas exchange efficiency. Previous work using magnetic resonance imaging (MRI) arterial spin labeling in athletes has shown that, after 45 min of heavy exercise, the spatial heterogeneity of pulmonary blood flow was increased in recovery. We hypothesized that the heterogeneity of regional specific ventilation (SV, the local tidal volume over functional residual capacity ratio) would also be increased following sustained exercise, consistent with the previously documented changes in blood flow heterogeneity. Trained subjects (n = 6, maximal O2 consumption = 61 ± 7 ml·kg(-1)·min(-1)) cycled 45 min at their individually determined ventilatory threshold. Oxygen-enhanced MRI was used to quantify SV in a sagittal slice of the right lung in supine posture pre- (preexercise) and 15- and 60-min postexercise. Arterial spin labeling was used to measure pulmonary blood flow in the same slice bracketing the SV measures. Heterogeneity of SV and blood flow were quantified by relative dispersion (RD = SD/mean). The alveolar-arterial oxygen difference was increased during exercise, 23.3 ± 5.3 Torr, compared with rest, 6.3 ± 3.7 Torr, indicating a gas exchange impairment during exercise. No significant change in RD of SV was seen after exercise: preexercise 0.78 ± 0.15, 15 min postexercise 0.81 ± 0.13, 60 min postexercise 0.78 ± 0.08 (P = 0.5). The RD of blood flow increased significantly postexercise: preexercise 1.00 ± 0.12, 15 min postexercise 1.15 ± 0.10, 45 min postexercise 1.10 ± 0.10, 60 min postexercise 1.19 ± 0.11, 90 min postexercise 1.11 ± 0.12 (P < 0.005). The lack of a significant change in RD of SV postexercise, despite an increase in the RD of blood flow, suggests that airways may be less susceptible to the effects of exercise than blood vessels.

Dexmedetomidine-related atrial standstill and loss of capture in a pediatric patient after congenital heart surgery.

OBJECTIVE: Dexmedetomidine (DEX; Precedex) is an alpha-2 adrenergic receptor agonist that produces anxiolysis and sleep-like sedation without narcosis or respiratory depression and has relatively few cardiovascular side effects. Given its favorable sedative properties combined with its limited effects on hemodynamic and respiratory function, it is widely used in pediatric intensive care and anesthesia settings. DESIGN: Case report. SETTING: Pediatric intensive care unit. PATIENT: A three-yr-old girl was admitted after mitral valve replacement for persistent severe mitral insufficiency. Her prior history was significant for tetralogy of Fallot which was repaired at nine months of age. A year later the patient developed mitral and tricuspid valve insufficiency and subsequently underwent mitral and tricuspid valve repair, pulmonary valve replacement, and a maze procedure (the latter was performed for persistent atrial flutter). Following that operation she developed sinus node dysfunction and had a permanent epicardial dual-chamber pacemaker implanted. Due to remaining severe mitral insufficiency the patient had increasing pulmonary symptoms, necessitating the most recent surgery to replace her mitral valve. INTERVENTIONS: On postoperative day two the patient was hemodynamically stable and weaning off mechanical ventilation. Tracheal extubation was anticipated to occur within the next 24 hrs. A DEX infusion of 0.6 mcg/kg/hr was initiated. A pacemaker interrogation performed on postoperative day three, 21 hrs after the initiation of DEX, revealed unsuccessful atrial capture. MEASUREMENTS AND MAIN RESULTS: Dexmedetomidine was subsequently discontinued and the patient's pacemaker was reinterrogated. The interrogation findings were similar to those seen prior to the initiation of DEX. CONCLUSION: As a result of these findings, caution is warranted in the administration of DEX to patients with predisposing conduction abnormalities and patients who are pacemaker-dependent.

The hybrid procedure for the borderline left ventricle.

UNLABELLED: IntroductionIn patients with varying degrees of left heart hypoplasia, it is often difficult to determine whether the left heart structures are adequate in size to support biventricular circulation. Historically, the decision to pursue a single ventricle or biventricular repair needed to be made early and was often irreversible. The hybrid procedure may be a better initial approach for patients with borderline left ventricles. METHODS: We describe a series of four patients with various congenital cardiac malformations, all of whom had borderline left ventricles. Based on pre-operative echocardiograms, several scoring systems and left ventricle volumes were used to predict the optimal type of repair. A left ventricular volume of 20 millilitres per square metre was used as the minimum cut-off value for adequacy of biventricular repair. RESULTS: The left ventricular volumes for the patients were 17.1, 23.7, 25.4, and 25.8 millilitres per square metre. In none of the four patients were the calculations unanimous in the recommendation to pursue either type of repair. All patients underwent the hybrid procedure and then eventual single ventricle palliation (two patients) or biventricular repair (two patients). All survived with a mean follow-up of 18 plus or minus 3.9 months. CONCLUSIONS: The hybrid procedure may be the best option in patients with a borderline left ventricle. It can serve as a bridge to a more definitive repair when patients are older, larger, and for whom the decision between single ventricle and biventricular repair can be more easily made.

Teaching hospital planning: a case study and the need for reform.

Academic teaching hospitals and their networks can best serve patients and other stakeholders by achieving critical mass and scope of clinical services, teaching and research. Successful hospital reconfigurations are associated with a convincing case and majority clinician buy-in. The inscrutable political decision to relocate services away from a major teaching hospital campus and into a merged Queensland Children's Hospital was determined without broad stakeholder consultation or a transparent and accountable business case. This compromised process poses a significant and enduring risk to patient care and Queensland's paediatric, perinatal, adolescent and obstetric academic teaching hospital services. As the proposed major stakeholder in Australia's public hospitals and medical workforce training, the federal government should review this decision using an effective methodology incorporating relevant criteria. National guidelines are needed to ensure best practice in the future planning and auditing of major health care projects. The medical profession is responsible for ensuring that health care policy complies with reliable evidence and good practice.

Effects of exercise training intensity on nocturnal growth hormone secretion in obese adults with the metabolic syndrome.

CONTEXT: Abdominal adiposity is associated with reduced spontaneous GH secretion, and an increased incidence of the metabolic syndrome, type 2 diabetes, and cardiovascular disease. Exercise training increases GH secretion, induces abdominal visceral fat loss, and has been shown to improve the cardiometabolic risk factor profile. However, little is known about the effects of endurance training intensity on spontaneous GH release in obese individuals. OBJECTIVE: Our objective was to examine the effects of 16 wk endurance training on spontaneous 12-h overnight GH secretion in adults with the metabolic syndrome. DESIGN AND SETTING: This randomized, controlled exercise intervention was conducted at the University of Virginia. PARTICIPANTS: A total of 34 adults with the metabolic syndrome (mean +/- sem: age: 49.1 +/- 1.8 yr) participated. INTERVENTION: Participants were randomized to one of three groups for 16 wk: no exercise training (control), low-intensity exercise training, or high-intensity training. MAIN OUTCOME MEASURE: Change in nocturnal integrated GH area under the curve (AUC) was calculated. RESULTS: Both exercise training conditions augmented within-group nocturnal GH AUC pretrain to post-training (low-intensity exercise training approximately (upward arrow) 49%, P < 0.05; and high-intensity training approximately (upward arrow) 65%, P < 0.01), and these changes were also greater than the changes in the control group (P < 0.01). The change in nocturnal GH AUC was inversely associated with the change in fat mass across the entire sample (r = -0.34; P = 0.051; n=34) but was not significantly associated with the change in abdominal visceral fat (r = 0.02; P = 0.920; n = 34). CONCLUSIONS: Sixteen wk of supervised exercise training in adults with the metabolic syndrome increases spontaneous nocturnal GH secretion independent of exercise training intensity.

Effect of exercise training intensity on abdominal visceral fat and body composition.

UNLABELLED: The metabolic syndrome is a complex clustering of metabolic defects associated with physical inactivity, abdominal adiposity, and aging. PURPOSE: To examine the effects of exercise training intensity on abdominal visceral fat (AVF) and body composition in obese women with the metabolic syndrome. METHODS: Twenty-seven middle-aged obese women (mean +/- SD; age = 51 +/- 9 yr and body mass index = 34 +/- 6 kg x m(-2)) with the metabolic syndrome completed one of three 16-wk aerobic exercise interventions: (i) no-exercise training (Control): seven participants maintained their existing levels of physical activity; (ii) low-intensity exercise training (LIET): 11 participants exercised 5 d x wk(-1) at an intensity < or = lactate threshold (LT); and (iii) high-intensity exercise training (HIET): nine participants exercised 3 d x wk(-1) at an intensity > LT and 2 d x wk(-1) < or = LT. Exercise time was adjusted to maintain caloric expenditure (400 kcal per session). Single-slice computed tomography scans obtained at the L4-L5 disc space and midthigh were used to determine abdominal fat and thigh muscle cross-sectional areas. Percent body fat was assessed by air displacement plethysmography. RESULTS: HIET significantly reduced total abdominal fat (P < 0.001), abdominal subcutaneous fat (P = 0.034), and AVF (P = 0.010). There were no significant changes observed in any of these parameters within the Control or the LIET conditions. CONCLUSIONS: The present data indicate that body composition changes are affected by the intensity of exercise training with HIET more effectively for reducing total abdominal fat, subcutaneous abdominal fat, and AVF in obese women with the metabolic syndrome.

Frequency and degree of change of peak transvalvular pressure gradient determined by two Doppler echocardiographic examinations in newborns and children with valvular congenital aortic stenosis.

The natural history of congenital aortic stenosis (AS) has been described predominantly using data derived from catheterization studies. Because of the inherent selection bias of many of these studies, this study was conducted to determine the course of valvular AS using data from serial echocardiograms, for which this bias is less pervasive. The medical records of 103 patients (mean age 3.3+/-3.8 years at time of diagnosis) with congenital AS were examined, and data from the initial and most recent echocardiograms before any intervention on the aortic valve were recorded. The average change in gradient for the entire study population was +1 mm Hg/patient-year. Forty percent (8 of 20) of patients diagnosed in the newborn period (<2 months) required intervention before 6 months of age, compared with 11% (9 of 83) of those diagnosed after the newborn period who required intervention at any time during the study period (p<0.01). Patients diagnosed at >or=1 year of age were less likely to have acute increases in gradient or need intervention; those older patients whose gradients progressed more rapidly were more likely to have significant (more than mild) aortic insufficiency than those whose gradients did not progress (55% vs 28%, p<0.05). In conclusion, congenital AS is usually a slowly progressive disease. Risk factors for more rapid gradient progression include diagnosis as a neonate and the development of significant aortic insufficiency.

NIH ImageJ and Slice-O-Matic computed tomography imaging software to quantify soft tissue.

OBJECTIVE: To compare reliability and limits of agreement of soft tissue cross-sectional areas obtained using Slice-O-Matic and NIH ImageJ medical imaging software packages. RESEARCH METHODS AND PROCEDURES: Abdominal and midthigh images were obtained using single-slice computed tomography. Two trained investigators analyzed each computed tomography image in duplicate. Adipose tissue and skeletal muscle cross-sectional areas (centimeters squared) were calculated using standard Hounsfield unit ranges (adipose tissue: -190 to -30 and skeletal muscle: -29 to 150). Regions of interest included abdominal total area, total fat area, subcutaneous fat area, visceral fat area (AVF), and right and left thigh total area, fat area, and skeletal muscle area. RESULTS: For all images, intra-investigator coefficients of variation ranged from 0.2% to 3.4% and from 0.4% to 5.6% and inter-investigator coefficients of variation ranged from 0.9% to 4.8% and 0.2% to 2.6% for Slice-O-Matic and NIH ImageJ, respectively, with intra- and inter-investigator coefficients of reliability of R(2) = 0.99. Mean AVF values for investigators A and B ranged from 168 to 170 cm(2) using Slice-O-Matic and NIH ImageJ. Bland-Altman analyses revealed that Slice-O-Matic and NIH ImageJ results were comparable. The mean differences (95% confidence intervals) between the AVF cross-sectional areas obtained using the Slice-O-Matic and NIH ImageJ medical imaging software were +2.5 cm(2) (-5.7, +10.8 cm(2)) or +1.4% (-3.4%, +6.4%). DISCUSSION: These findings show that both the Slice-O-Matic and NIH ImageJ medical imaging software systems provide reliable measurements of adipose tissue and skeletal muscle cross-sectional areas.

The metabolic syndrome, hypertriglyceridemic waist, and cardiometabolic risk factor profile in obese women.

The hypertriglyceridemic waist (HTGW) and metabolic syndrome (MS) are associated with increased cardiometabolic risk. We evaluated the impact of the HTGW on cardiometabolic risk factors in obese women diagnosed with the MS. Thirty-six abdominally obese women with the MS as defined by the International Diabetes Federation (IDF) [(mean (SD); age 49 (11) y, ht 165 (6) cm, wt 95 (16) kg] participated. The HTGW was defined as follows: a waist circumference ≥80 cm and triglycerides ≥1.7 mM. Unpaired t-tests and Analysis of Covariance (ANCOVA) were employed to detect mean differences between women with MS plus or minus HTGW. Women with the MS plus HTGW had higher total cholesterol (16%, p=0.015), VLDL-cholesterol (97%, p<0.001), non-HDL-cholesterol (16%, p=0.002), insulin (40%, p=0.043), and abdominal visceral fat (24%, p=0.100), and lower total HDL-cholesterol (6%, p=0.024), HDL(3) (11%, p=0.031) and Quantitative Insulin Sensitivity Check Index (QUICKI) (5%, p=0.068) compared with women with the MS minus HTGW. Thus, the presence of the HTGW was accompanied by a worsened cardiometabolic risk factor profile in these obese women with the MS. In particular, women with the MS plus HTGW were more insulin resistant compared to women with the MS minus HTGW. In conclusion, the presence of the HTGW in obese women with the MS exacerbates insulin resistance and cardiometabolic risk factors.

Heart rate recovery does not predict endothelial function in obese women.

The purpose of the present study was to examine the relationship between heart rate recovery (HR(REC)) and endothelial function in obese women with the metabolic syndrome. The metabolic syndrome has been associated with increased cardiometabolic risk including endothelial dysfunction. However, measurement of endothelial function via flow-mediated dilation (FMD) requires expensive equipment and qualified medical personnel, and therefore may be impractical in some healthcare settings. Heart rate recovery (HR(REC)) has predictive utility with respect to endothelial function in individuals with suspected coronary artery disease and individuals with the metabolic syndrome also have elevated risk for developing coronary artery disease. Thirty-one obese, sedentary women (age: 47.7±11.2 yr, mean±SD) who met the International Diabetes Federation criteria for the metabolic syndrome underwent a brachial artery ultrasound to determine FMD and nitroglycerine-mediated dilation (NTG). HR(REC) was assessed during 5 min of active recovery following a standardized VO(2 Peak) treadmill protocol. Results revealed that the %FMD was not correlated to HR(REC) when examined across all participants (r= 0.067, p=0.72). However, this relationship was significant in participants with impaired FMD (n=16, %FMD<6%) (r=0.71, p=0.002). Although HR(REC) may be a significant correlate of FMD in women with the metabolic syndrome and with prevalent endothelial dysfunction, it was not a significant correlate across all women with the metabolic syndrome. The present data do not support the use of HR(REC) as a possible screening tool for endothelial dysfunction in obese women with the metabolic syndrome.

Comparison of Borg- and OMNI-RPE as markers of the blood lactate response to exercise.

PURPOSE: To examine the utility of the Borg (6-20) and adult OMNI walk/run (0-10) ratings of perceived exertion (RPE) scales as markers of the blood lactate response to exercise. METHODS: Thirty-six (26 females and 10 males) individuals with the metabolic syndrome (mean+/-SEM: age, 45.8+/-2.0 yr; height, 168.4+/-1.3 cm; weight, 100.4+/-3.6 kg) completed a continuous peak oxygen uptake (VO2peak)/lactate threshold (LT) treadmill protocol. VO2 (mL.kg.min), blood lactate concentration (BLC, mM), and heart rate (bpm) were measured at the end of each stage. RPE were assessed at 2:15 and 2:45 of each 3-min stage using both RPE scales presented in a counterbalanced order. Participants were read standardized instructions specific to each scale. The LT and BLC of 2.5 and 4.0 mM were determined from the blood lactate-velocity relationship. RESULTS: The mean Borg, OMNI, and standardized (to the Borg scale) OMNI-RPE values at the LT and BLC of 2.5 mM, 4.0 mM, and peak ranged from 10.1 to 16.9, 3.1 to 8.2, and 9.9 to 17.1, respectively. No differences were observed between Borg and standardized OMNI-RPE at any exercise intensity. The correlation within and between Borg- and OMNI-RPE and the velocities associated with LT, BLC of 2.5 mM, 4.0 mM, and peak ranged from r=0.82 to 0.93 (P<0.01). Mean differences (95% CI) between the Borg- and standardized OMNI-RPE at LT, and BLC of 2.5 mM, 4.0 mM, and peak were 0.27 (-2.26, 2.80), -0.48 (-3.14, 2.18), -0.29 (-2.92, 2.35), and 0.10 (-1.65, 1.84), respectively. CONCLUSION: Both the Borg and OMNI walk/run scales demonstrate predictive utility as markers of the blood lactate response to incremental exercise in individuals with the metabolic syndrome.