Cardiovascular response to brisk walking on different surfaces in an innovative senior playground: a randomized trial in older adults

Brisk walking is a simple exercise for older adults. We aimed to assess the cardiovascular response to a short bout of brisk walking on walking loops in an innovative senior playground in Thailand. Twenty older adults were randomly assigned to brisk walking on artificial turf (AT group, n = 10) or an uneven surface (US group, n = 10). We assessed cardiovascular parameters, average walking speed, and rate of perceived exertion. Blood pressure, heart rate, rate-pressure product, and rate perceived exertion were significantly increased, while the mean RR interval of heart rate variability was significantly decreased in both AT and US groups after exercise compared with pre-exercise (p < 0.05). A greater change in systolic blood pressure was observed in the US group than in the AT group (p < 0.05). These data indicated that brisk walking on AT and US increases cardiovascular response. Our findings provide information on planning exercise programs for older adults.

Changes in rate-pressure product associated with pregnancy

BACKGROUND

In nonpregnant individuals, the rate-pressure product, the product of heart rate and systolic blood pressure, is used as a noninvasive surrogate of myocardial O2 consumption during cardiac stress testing. Pregnancy is considered a physiological cardiovascular stress test. Evidence describing the impact of pregnancy on myocardial O2 demand, as assessed by the rate-pressure product, is limited.

OBJECTIVE

This study aimed to describe changes in the rate-pressure product for each pregnancy trimester, during labor and delivery, and the postpartum period among low-risk pregnancies.

STUDY DESIGN

This was a retrospective cohort study that assessed uncomplicated pregnancies delivered vaginally at term. We collected rate-pressure product (heart rate × systolic blood pressure) values preconception, during pregnancy for each trimester (at ≤13 weeks + 6/7 days, at 14 weeks + 0/7 days through 27 weeks + 6/7 days, and at ≥28 weeks + 0/7 days), during the labor and delivery encounter (hospital admission until complete cervical dilation, complete cervical dilation until placental delivery, and after placental delivery until hospital discharge), and during the outpatient postpartum visit at 2 to 6 weeks after delivery. We calculated the percentage change at each time point from the preconception rate-pressure product (delta rate-pressure product). We used a mixed-linear model to analyze differences in the mean delta rate-pressure product over time and the influence of prepregnancy age, prepregnancy body mass index, and neuraxial anesthesia status during labor and delivery on these estimates.

RESULTS

Our cohort comprised 316 patients. The mean rate-pressure product increased significantly from preconception starting at the third trimester of pregnancy and during labor and delivery (P≤.05). The mean delta rate-pressure product peaked at 12% and 38% in the third trimester and during labor and delivery, respectively. Prepregnancy body mass index was inversely correlated with the mean delta rate-pressure product changes (estimate, -0.308; 95% confidence interval, -0.536 to -0.80; P=.008). In contrast, neither the prepregnancy age, nor neuraxial anesthesia status during labor had a significant influence on this parameter.

CONCLUSION

This study validates the transient but significant increase in the rate-pressure product, a clinical estimate of myocardial O2 demand, during uncomplicated pregnancies delivered vaginally at term. Pregnant individuals with lower prepregnancy body mass index experienced a sharper increase in this parameter. Patients who receive neuraxial anesthesia during labor and delivery experience similar changes in the rate-pressure product as those who did not.

Comparative analysis of health-related fitness in patients with acute versus chronic Chagas disease

INTRODUCTION

Although Chagas disease causes high levels of morbidity, the muscle function and tolerance to physical activity in Chagas disease patients are still not completely understood.

OBJECTIVE

To compare health-related fitness of patient groups with acute Chagas disease versus chronic Chagas disease.

MATERIALS AND METHODS

We conducted a cross-sectional study involving 18 patients. The data were obtained from patient´s records, and functional capacity was measured with the sixminute walk test, the peripheral muscle strength with handgrip strength, and respiratory muscle strength using the maximum inspiratory pressure and the maximum expiratory pressure.

RESULTS

The 18 patients were divided in two groups: acute Chagas disease (n=9) and chronic Chagas disease (n=9). The distance walked in the six-minute walk test was lower than the predicted distance walked in both groups (p < 0.0001). The maximum expiratory pressure was lower than the predicted one (p = 0.005), and statistically significant for chronic Chagas disease patients (p = 0.02). Heart rate increased faster in the chronic Chagas disease group within the first two minutes of the six-minute walk test (p = 0.04). The sixminute walk test in the acute Chagas disease group presented a strong correlation with peripheral muscle strength (p = 0.012) and maximum inspiratory pressure (p = 0.0142), while in the chronic Chagas disease group, only peripheral muscle strength and maximum inspiratory pressure were correlated (p = 0.0259).

CONCLUSION

The results suggest lowered functional capacity and reduced respiratory and peripheral muscle strength in patients with Chagas disease, although no differences were observed between groups. The early increase in heart rate during exercise in the chronic Chagas disease group implies a greater myocardial overload.

Comparison of esketamine versus dexmedetomidine for attenuation of cardiovascular stress response to double-lumen tracheal tube intubation: a randomized controlled trial

Introduction

The insertion of a double-lumen tracheal tube may cause a transient but more intense sympathetic response. We examined the effects of esketamine vs. dexmedetomidine as an adjuvant to anesthesia induction to blunt double lumen tracheal (DLT) intubation induced cardiovascular stress response.

Methods

In a randomized, double-blind trial, 78 adult patients scheduled for elective thoracotomy under general anesthesia requiring DLT intubation were enrolled. The patients were randomly divided into three groups: each group received one of the following drugs prior to induction of anesthesia: dexmedetomidine 0.8 µg/kg (Group A), esketamine 0.5 mg/kg (Group B), or normal saline (group C). The primary outcome was the incidence of a DLT intubation-related cardiovascular stress response, defined as an increase in mean arterial pressure or heart rate of >30% above the baseline values. The secondary outcomes were changes in hemodynamic and cardiac function.

Results

The incidence of the response to cardiovascular stress was 23.1%, 30.8%, and 65.4% in groups A, B, and C, respectively. There was a significant decrease in intubation response in groups A and B in comparison with group C (P < 0.01); however, there was no significant difference between group A and group B (P > 0.05). Following the drug infusion and the induction of anesthesia, there was a significant decrease in HR and cardiac output in group A compared with group B. In contrast, no significant differences were observed in the left ventricular ejection fraction or in stroke volume between the three groups during induction of anesthesia.

Discussion

Esketamine 0.5 mg/kg and dexmedetomidine 0.8 µg/kg attenuate cardiovascular stress responses related to DLT intubation. As adjuvants to etomidate induction, they do not impair cardiac function (ChiCTR1900028030).

Combined effects of whole-body vibration and dynamic squats on cardiovascular and salivary biomarker responses in healthy adults

This study aimed to investigate the acute effects of combining whole-body vibration with dynamic squats on cardiovascular and salivary bio-marker responses in healthy adults. A randomized crossover design was conducted with 20 healthy adults. Each participant underwent three exercise sessions, with a 2-week washout period between each session. The sessions consisted of: (1) whole-body vibration (VB) at 25 Hz for 2 minutes, with an amplitude of 2 mm, and 2 minutes of rest between sets, for a total of 5 sets; (2) dynamic squats (SQ) performed 15 times within 2 minutes, with a 2-minute rest between sets, for a total of 5 sets; and (3) a combination of whole-body VB and SQ (VB+SQ). The cardiovascular variables and salivary biomarkers related to exercise intensity were assessed. Only the VB+SQ session significantly decreased the unstimulated salivary flow rate, and caused greater changes in heart rate, systolic blood pressure, mean arterial pressure, rate-pressure product, and heart rate variability compared to VB or SQ alone. Moreover, the VB+SQ session significantly increased the salivary total protein concentration from 0.56±0.05 mg/mL (baseline) to 0.74± 0.06 mg/mL (postexercise condition) and the salivary alpha-amylase activity from 33.83±5.56 U/mL (baseline) to 63.63±12.33 U/mL (postexercise condition) (P<0.05). These changes were recovered at 1-hr postexercise condition. Our findings provide information for designing exercise programs that incorporate VB+SQ to enhance hemodynamic and cardiac autonomic responses in healthy adults and for application during rehabilitation periods.

Chronic Effects of Different Intensities of Interval Training on Hemodynamic, Autonomic and Cardiorespiratory Variables of Physically Active Elderly People

Interval training (IT) is a very efficient method. We aimed to verify the chronic effects of IT with different intensities on hemodynamic, autonomic and cardiorespiratory variables in the elderly. Twenty-four physically active elderly men participated in the study and were randomized into three groups: Training Group A (TG_A, n = 8), Training Group B (TG_B, n = 8) and control group (CG, n = 8). The TG_A and TG_B groups performed 32 sessions (48 h interval). TG_A presented 4 min (55 to 60% of HRmax) and 1 min (70 to 75% of HRmax). The TGB training groups performed the same protocol, but performed 4 min at 45 to 50% HRmax and 1 min at 60 to 65% HRmax. Both training groups performed each set six times, totaling 30 min per session. Assessments were performed pre (baseline) after the 16th and 32nd intervention session. The CG performed only assessments. Hemodynamic, autonomic and cardiorespiratory (estimated VO_2max) variables were evaluated. There were no significant differences between protocols and times (p > 0.05). However, the effect size and percentage delta indicated positive clinical outcomes, indicating favorable responses of IT. IT may be a strategy to improve hemodynamic, autonomic and cardiorespiratory behavior in healthy elderly people.

Association of rate pressure product trajectories at an early age with left ventricular hypertrophy in midlife: a prospective cohort study

The joint effect of blood pressure (BP) and heart rate (HR) on cardiovascular disease is unclear. Rate pressure product (RPP), the product of systolic BP and HR, is assessed in this study. This study aimed to determine the longitudinal patterns of RPP from childhood to adulthood and to explore the relationship between RPP trajectories in early life and left ventricular hypertrophy (LVH) in midlife. We included individuals with 3 or more RPP values from 7 visits over a 30-year follow-up period in the Hanzhong Adolescent Hypertension Study cohort to fit trajectory groups and performed logistic regression to evaluate the relative risk of developing LVH. Three discrete trajectories in RPP were identified among 2412 participants assessed from childhood to middle-aged adulthood, which were tagged as "low stable," "moderate stable," and "moderate increasing". A higher waist-to-hip ratio, smoking, alcohol consumption, hypertension, diabetes, and hyperlipidemia were associated with increased RPP trajectories. The Cornell voltage product was positively correlated with RPP in 2017 and was higher in the moderate-stable and moderate-increasing groups than in the low-stable group in RPP trajectories. Compared with the low-stable group, the ORs of LVH were 1.65 (1.13, 2.92) for the moderate-stable and 3.56 (2.26, 5.44) for the moderate-increasing group. Subjects with moderate-stable and moderate-increasing trajectories showed higher probabilities of LVH at an elderly age than those in the low stable trajectory group even after adjusting for multiple cardiovascular risk factors. RPP trajectories are identifiable from childhood and are associated with LVH in midlife. Monitoring RPP trajectories from early life may be an effective approach to predict cardiovascular health status later in life.

Comparison of the Results of Cardiopulmonary Exercise Testing between Healthy Peers and Pediatric Patients with Different Echocardiographic Severity of Mitral Valve Prolapse

Patients with mitral valve prolapse (MVP) have been reported to have exercise intolerance. However, the underlying pathophysiological mechanisms and their physical fitness remain unclear. We aimed to determine the exercise capacity of patients with MVP through the cardiopulmonary exercise test (CPET). We retrospectively collected the data of 45 patients with a diagnosis of MVP. Their CPET and echocardiogram results were compared with 76 healthy individuals as primary outcomes. No significant differences regarding the patient's baseline characteristics and echocardiographic data were found between the two groups, except for the lower body mass index (BMI) of the MVP group. Patients in the MVP group demonstrated a similar peak metabolic equivalent (MET), but a significantly lower peak rate pressure product (PRPP) (p = 0.048). Patients with MVP possessed similar exercise capacity to healthy individuals. The reduced PRPP may indicate compromised coronary perfusion and subtle left ventricular function impairment.

Chronic Effects of Different Types of Neuromuscular Training on Hemodynamic Responses Estimated VO2max, and Walking Performance in Older People

This paper investigated the effects over time of different forms of neuromuscular training on hemodynamic responses, the estimated VO_2max, and walking performance. 105 older adults were randomly organized into three groups: RG_A, RG_B, and the Control Group (CG). RG_A and RG_B did 4 weeks of adaptation phase training and 12 weeks of intervention with different loads: moderate loads for RG_B. and higher loads for RG_A. A pre- and post-evaluation of the resting heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), double product (DP), estimated VO_2max, and walking performance were assessed. Significant differences were observed for SBP, DBP, HR, and DP. For SBP, a post-evaluation reduction was observed only in RG_A (p = 0.007) and when comparing RG_A with the Control Group (p < 0.000). For the absolute VO_2max, a significant improvement was seen in RG_B compared to RG_A (p = 0.037) and CG (p < 0.000). For the relative VO_2max, RG_B scored significantly higher than RG_A (p < 0.000) and CG (p < 0.000), post-intervention. For the walk test, a significant reduction in completion times was observed for RG_A (p = 0.027) and RG_B (p < 0.000), and for RG_B compared to RG_A (p = 0.000) and CG (p < 0.000). Resistance training can be an excellent strategy for hemodynamic and cardiorespiratory improvement in the elderly.

Correlation between impaired hemodynamic response and cardiopulmonary fitness in middle-aged type 2 diabetes mellitus patients: a case-control study

PURPOSE

Impaired cardiorespiratory fitness (CRF) is a predictor of mortality in patients with type 2 diabetes mellitus (T2DM). It is still not known how the exercise hemodynamic response correlates with CRF. The purpose was to assess the correlation between hemodynamic changes and CRF in middle-aged patients with T2DM.

METHODS

After 1:1 matching by age and sex, 139 T2DM patients and 139 non-T2DM controls who completed the exercise treadmill test were included. Maximal aerobic capacity (VO_2max), exercise-induced changes in heart rate (ΔHR), systolic blood pressure (ΔSBP), diastolic blood pressure (ΔDBP), and rate-pressure product (ΔRPP) were measured. HRR₁ was calculated as the maximum heart rate minus the heart rate after 1 min of rest.

RESULTS

Compared to the control population, T2DM patients had decreased ΔHR (87 (77, 97) v 93 (84, 104) bpm, p < 0.05), ΔRPP (3833.64 ± 1670.34 v 4381.16 ± 1587.78 bpm∙mmHg, p < 0.05), HRR₁ (21 (14, 27) v 21 (17, 27) bpm, p < 0.05), and VO_2max (32.76 ± 5.63 v 34.68 ± 5.70 ml/kg/min, p < 0.05). Multiple linear regression analysis showed that ΔHR and HRR₁, yielded a positive correlation with VO_2max in T2DM patients (β = 0.325, P < 0.001; β = 0.173, P = 0.01).

CONCLUSION

The presence of impaired hemodynamic response and VO_2max in middle-aged T2DM patients and the association of impaired ΔHR, HRR₁, and VO_2max may indicate a physiological pathway of impaired CRF, and our results support the need for cardiorespiratory screening and individualized treatment of middle-aged T2DM patients.

Gravitational Dose‐Response Curves for Acute Cardiovascular Hemodynamics and Autonomic Responses in a Tilt Paradigm

Background

The cardiovascular system is strongly dependent on the gravitational environment. Gravitational changes cause mechanical fluid shifts and, in turn, autonomic effectors influence systemic circulation and cardiac control. We implemented a tilt paradigm to (1) investigate the acute hemodynamic response across a range of directions of the gravitational vector, and (2) to generate specific dose‐response relationships of this gravitational dependency.

Methods and Results

Twelve male subjects were tilted from 45° head‐up tilt to 45° head‐down tilt in 15° increments, in both supine and prone postures. We measured the steady‐state hemodynamic response in a range of variables including heart rate, stroke volume, cardiac output, oxygen consumption, total peripheral resistance, blood pressure, and autonomic indices derived from heart rate variability analysis. There is a strong gravitational dependence in almost all variables considered, with the exception of oxygen consumption, whereas systolic blood pressure remained controlled to within ≈3% across the tilt range. Hemodynamic responses are primarily driven by differential loading on the baroreflex receptors, combined with differences in venous return to the heart. Thorax compression in the prone position leads to reduced venous return and increased sympathetic nervous activity, raising heart rate, and systemic vascular resistance while lowering cardiac output and stroke volume.

Conclusions

Gravitational dose‐response curves generated from these data provide a comprehensive baseline from which to assess the efficacy of potential spaceflight countermeasures. Results also assist clinical management of terrestrial surgery in prone posture or head‐down tilt positions.

Acute Effects of Wearing Different Surgical Face Masks during High-Intensity, Short-Rest Resistance Exercise on Cardiorespiratory and Pulmonary Function and Perceptual Responses in Weightlifters

This study investigated the effect of wearing a typical surgical mask (SM) or a three-dimensional (3D) SM (3DSM) during whole-body, high-intensity, short-rest resistance exercise on cardiorespiratory, respiratory, and perceptual comfort responses in weightlifters. Twenty elite weightlifters (6 women and 14 men; age = 24.1 ± 4.9 years; height: 167.45 ± 7.60 cm; body mass = 76.48 ± 19.86 kg) who participated in this study performed 3 resistance exercise sessions in a randomized order: (1) without a mask (NM), (2) while wearing a typical SM, and (3) while wearing a 3DSM. Resistance exercise consisted of a descending pyramid scheme starting at 10 repetitions, with a decrease of one repetition per set for the back squat, bench press, and deadlift, as fast as possible at 75% of the one-repetition maximum. Cardiorespiratory and pulmonary function and comfort were measured. Across all conditions, effective postexercise hypotension (PEH) was noted in terms of decreased systolic blood pressure (−4.64%), diastolic BP (−5.36%), mean arterial pressure (−5.02%), and ankle–brachial index (−6.84%). However, the heart rate (40.34%) and rate of pressure product (33.60%) increased, and no effects on pulmonary function were observed in the three conditions. The participants reported higher breathing resistance and tightness when wearing a typical SM than when wearing a 3DSM or no mask. Therefore, both wearing and not wearing a face mask during whole-body, high-intensity, short-rest resistance exercise promoted PEH and exerted no detrimental effect on pulmonary function. Coaches, trainers, and athletes should consider wearing a 3DSM during resistance exercise.

Does wearing a mask while exercising amid COVID-19 pandemic affect hemodynamic and hematologic function among healthy individuals? Implications of mask modality, sex, and exercise intensity

OBJECTIVES

We investigated how wearing a mask - and its modality (surgical vs. N95) - affect hemodynamic and hematologic function in males and females across two exercise intensities (submaximal (SUB) and maximal (MAX)).

METHODS

144 individuals participated in the present study and were randomly allocated to three mask groups of 48 (N95, SURGICAL, and NO MASK) with two exercise subgroups for each mask group (MAX, n = 24; SUB, n = 24) for both sexes. Participants in each experimental group (N95SUB, N95MAX; SURSUB, SURMAX; SUB, MAX) were assessed for their hemodynamic and hematologic function at baseline and during recovery after exercise.

RESULTS

No significant differences were noted for either hemodynamic or hematologic function at post-exercise as compared to baseline with regard to mask modality (P > 0.05). Heart rate (HR) for maximal intensity were significantly greater at 1 min post-exercise in N95 as compared to SURGICAL (P < 0.05). No differences were noted for hemodynamic and hematologic function with N95 and SURGICAL compared to NOMASK for either intensity (P > 0.05). Females showed significantly greater HR values at 1 min post-exercise in N95 as compared to NO MASK, but no significant differences were noted for hematological function between sexes (P > 0.05).

CONCLUSION

Our findings show that wearing a face mask (N95/surgical) while exercising has no detrimental effects on hemodynamic/hematologic function in both males and females, and suggest that wearing a mask, particularly a surgical mask, while exercising during the ongoing pandemic is safe and poses no risk to individual's health. Future studies examining physiological responses to chronic exercise with masks are warranted.

Exploring relationships between inspiratory muscle strength and functional capacity in childhood cancer survivors: a pilot study

Childhood cancer survivors (CCS) experience short- and long-term side effects from cancer treatment that often impair functional capacity. Inspiratory muscle weakness is a potential mechanism for reduced functional capacity. The objective of this pilot study was to examine the relationship between inspiratory muscle strength and functional capacity in 10 CCS. Inspiratory muscle strength was measured by maximal inspiratory pressure (MIP) while functional capacity was measured by the two-minute walk test (2MWT), the physiological cost index and hemodynamic response to exercise according to changes in heart rate, blood pressure and rate-pressure product (RPP). Overall, MIP and 2MWT distance were below predicted values. Hemodynamic responses to the 2MWT were consistent with little variation, except for elevated diastolic blood pressure (DBP) response. MIP had significant relationships with resting DBP (Spearman's rank correlation coefficient [r_s] = -0.70; p = 0.03) and DBP response (r_s = 0.72; p = 0.02). Time since completion of cancer treatment had a significant positive relationship with RPP response (r_s = 0.67; p = 0.03). Inspiratory muscle weakness in childhood cancer could be an indicator of skeletal muscle dysfunction and should be considered when symptoms of dyspnea or poor functional capacity arise. Inspiratory muscle strength was found to be related to changes in blood pressure in CCS. Future studies should further investigate these relationships and the impact of inspiratory muscle training on hemodynamics and functional capacity in CCS.

Effects of atorvastatin on sevoflurane postconditioning in in vivo rabbit hearts

OBJECTIVES

Myocardial ischemia-reperfusion injury is a phenomenon that promotes myocardial damage when the blood supply returns to the tissue after a period of ischemia. Anesthetic postconditioning involves myocardial protection against myocardial I/R injury. The effects of atorvastatin (ATV) on sevoflurane postconditioning against myocardial ischemia-reperfusion injury have not been thoroughly studied. The present study aimed to investigate if ATV interacts synergistically with sevoflurane postconditioning against myocardial infarction in rabbit hearts in vivo.

METHODS

Twenty-eight male rabbits underwent 30 min of left anterior descending coronary artery occlusion that was followed by reperfusion for 180 min under ketamine/xylazine (K/X) anesthesia. Rabbits were randomly assigned to four groups that included Group K/X (under K/X anesthesia only), Group POST (sevoflurane exposure at initial reperfusion), Group ATV (ATV 5 mg/kg/day administered before ischemia), and Group ATV + POST (POST intervention with atorvastatin administered once daily for 3 days). At the end of reperfusion, the myocardial infarct size and the area at risk were both measured.

RESULTS

The mean infarct sizes in the POST, ATV, and ATV + POST groups were significantly smaller compared to those in the K/X group. Furthermore, the mean infarct size in Group ATV + POST was significantly smaller than was that in Group POST and significantly smaller compared to that in Group ATV.

CONCLUSION

The combination of sevoflurane postconditioning and pre-administration of ATV further reduced the myocardial infarction size compared to that observed with sevoflurane postconditioning alone or ATV alone. Our data suggest that sevoflurane postconditioning and ATV may function additively to enhance cardioprotection.

Decreased baroreflex sensitivity is associated with cardiometabolic risks and prehypertension status in early-postmenopausal women

OBJECTIVE

We studied the link of decreased baroreflex sensitivity (BRS) to cardiometabolic risks and prehypertension status in postmenopausal women during their early menopausal phase.

METHODS

Premenopausal women (n = 55) and early-postmenopausal women (n = 50) of age group between 40 and 55 years were recruited for the study, and their anthropometric parameters, complete battery of autonomic function tests (AFT), BRS, hormone levels, and cardiometabolic risk parameters were measured and compared between two groups. Correlation analysis of BRS with various physiological and biochemical parameters in these two groups were performed. Multiple regression analysis of BRS with various other associated factors in postmenopausal subjects and bivariate logistic regression analysis for assessing prediction of prehypertension status by BRS in postmenopausal group were performed.

RESULTS

There was a significant difference in AFT and metabolic parameters between premenopausal and postmenopausal women. Sympathovagal imbalance (increased sympathetic and decreased parasympathetic) was prominent in early-postmenopausal women. Decreased BRS, the marker of cardiovascular (CV) risk was found to be significant (P < .001) and correlated with various cardiometabolic parameters in early-postmenopausal subjects. Multiple regression analysis demonstrated that decreased BRS is independently linked to parameters of decreased vagal activity, inflammation, and oxidative stress in early-postmenopausal group. Decreased BRS could predict prehypertension status in early-postmenopausal subjects as confirmed by bivariate logistic regression analysis.

CONCLUSION

Sympathovagal imbalance, decreased BRS and considerable metabolic derangements were observed in women in their early phase of menopause. Decreased BRS appears to be associated with the cardiometabolic risks in these women. Prehypertension status in early-postmenopausal subjects could be predicted by decreased BRS.

Interaction effect of green tea consumption and resistance training on office and ambulatory cardiovascular parameters in women with high-normal/stage 1 hypertension

This study aimed to investigate the chronic effects of green tea (GT) extract and resistance training (RT) on ambulatory and office blood pressure (BP), heart rate (HR), and rate-pressure product (RPP) in a sample of Iranian women with high-normal/stage 1 hypertension. Forty-four middle-aged sedentary women participated in this randomized, double-blind, placebo-controlled study. They were randomly assigned to one of four groups: GT and RT (GR, n = 11), RT (n = 10), GT (n = 10), or control (n = 13). Three weeks of GT consumption were followed by six weeks of the interaction with RT. GR and RT groups performed two circuits of RT at %50 of 1RM two days per week. RT and control groups also received placebo (maltodextrin) with the same timing. The changes of each variable from baseline to post-intervention were compared between the groups using the ANOVA test, and effect size (ES) statistic was also calculated. In comparison with the control group, significant reductions were found for office systolic BP (SBP, 8%, ES = 1.22), and 24 h-SBP (5%, ES = 1.2) in the RT group. However, GR group showed significant decreases in office SBP (10.5%, ES = 1.45), mean BP (8%, ES = 1.11), RPP (13%, ES = 1.47), 24 h-SBP (5%, ES = 1.21), and 24 h-RPP (10%, ES = 1.15). The interaction of regular RT and GT consumption seems to induce more beneficial effects on some important parameters including MBP and RPP when compared to RT or GT alone.

Rate-Pressure Product Responses to Static Contractions Performed at Various Altitudes

Simmonds, Michael J., Surendran Sabapathy, and Jean-Marc Hero. Rate-pressure product responses to static contractions performed at various altitudes. High Alt Med Biol. 22: 166-173, 2021. Background: Adventure tourism has led to an unprecedented number of individuals being exposed to altitude, including those with subclinical cardiometabolic disorders. The disproportionate hemodynamic challenge associated with small-muscle static activities is potentially dangerous at altitude as these may compound the risk for cardiac events. We thus examined the cardiovascular response to, and during recovery from, static exercise performed at altitude. Methods: Eighteen individuals completed this study at three altitudes (sea level; ∼1,500 m; ∼3,000 m) in central Nepal. At each altitude, individuals performed two handgrip contractions for 2 minutes at the same intensity (30% maximal voluntary contraction [MVC]), with two distinct recovery periods: during control recovery was completed quietly at rest, while during ischemic challenge recovery was conducted with a cuff occluding the upper limb. Results: Oxygen saturation decreased during ascent to 1,500 m (-2%) and 3,000 m (-8%), compared with sea level. Handgrip MVC was not affected by altitude, although heart rate at rest (∼70 beat/min), during static exercise (range ∼90-95 beat/min), and during recovery in both conditions (each ∼70 beat/min) was significantly increased by ∼15% at 3,000 m, but not 1,500 m. The magnitude of the muscle metaboreflex during recovery from static exercise was unaffected by altitude; however, the rate-pressure product was significantly elevated by ∼10% during and following static exercise at 3,000 m. Conclusions: A significant increase in the rate-pressure product during static exercise was observed at altitude, which persisted during recovery. Individuals at risk for cardiac events should use awareness of static contractions while at altitude, especially considering that stress induced by static exercise is additive to that of dynamic activities such as hiking.

Dosing study of esmolol for reducing hemodynamic changes during lightwand intubation

Background

Lightwand is a convenient tool that can be used instead of a laryngoscope for intubation. Tracheal intubation causes direct stimulation of the larynx, drastically increasing hemodynamic values including blood pressure and heart rate. This study aims to identify the effect of different doses of esmolol on hemodynamic changes during lightwand intubation.

Methods

The study subjects included 140 patients who underwent general anesthesia for elective surgery. The patients were randomly divided into four groups (35 patients in each group). The ‘C’ group only received 20 ml of normal saline, while the ‘E0.5’, ‘E1’, and ‘E2’ groups received 20 ml of normal saline containing esmolol—0.5 mg/kg, 1 mg/kg, and 2 mg/kg, respectively, injected 2 min prior to intubation. The patients’ blood pressure, heart rate, and rate-pressure product were measured six times, before and after the intubation.

Results

The degree of heart rate elevation was suppressed in the E1 and E2 groups compared to the C group, and RPP after intubation significantly decreased in the E2 group compared to the C group.

Conclusions

Esmolol injection, 1-2 mg/kg, prior to lightwand intubation effectively blunts heart rate elevation, and 2 mg/kg of esmolol injection blunts rate-pressure product elevation.

Association of double product and pulse pressure with cardiovascular and all-cause mortality in the LURIC study

Systolic (SBP) and diastolic blood pressure (DBP) and mean arterial pressure (MAP) are risk factors for cardiovascular mortality (CVM). Pulse pressure (PP) is considered as an easily available marker of vascular stiffness and the double product (DP) as a marker of cardiac workload. Therefore, we have examined the predictive value of PP and DP in the Ludwigshafen Risk and Cardiovascular Health study, a monocentric cohort study of 3316 patients referred to coronary angiography. An increase of SBP or PP by 1mmHg increased the risk of CVM with hazard ratios of 1.009 (95% CI, 1.005-1.012) and 1.016 (1.012-1.020), respectively. Increasing DP by 100 mm Hg/min was associated with a 1.010 (1.007-1.013) higher risk of CVM. In patient subgroups with coronary artery disease (CAD) and heart failure (HF), PP and DP predicted CVM better than SBP or MAP. In a multivariate analysis adjusted for sex, BMI, diabetes, eGFR, hazard ratios for CVM for z-standardized PP, DP, SBP, and HR were 1.20, 1.16, 1.12, and 1.14. After adding age to the multivariate analysis, only DP and HR remained significant. We provide evidence that PP and DP are powerful predictors of CVM and all-cause mortality in a CV medium- to high-risk population, especially in patients with CAD and HF. While DP proved to be an independent predictor of cardiovascular and all-cause mortality also in multivariate analysis, PP was no independent predictor in our cohort with widespread antihypertensive treatment (>85%). PP is associated with age, presence of diabetes, obesity, and impaired renal function.

Bayesian Estimation of Correlation between Measures of Blood Pressure Indices, Aerobic Capacity and Resting Heart Rate Variability Using Markov Chain Monte Carlo Simulation and 95% High Density Interval in Female School Teachers

Background: Several explanations regarding the disparity observed in the literature with regard to heart rate variability (HRV) and its association with performance parameters have been proposed: the time of day when the recording was conducted, the condition (i.e., rest, active, post activity) and the mathematical and physiological relationships that could have influenced the results. A notable observation about early studies is that they all followed the frequentist approach to data analyses. Therefore, in an attempt to explain the disparity observed in the literature, the primary purpose of this study was to estimate the association between measures of HRV indices, aerobic performance parameters and blood pressure indices using the Bayesian estimation of correlation on simulated data using Markov Chain Monte Carlo (MCMC) and the equal probability of the 95% high density interval (95% HDI). Methods: The within-subjects with a one-group pretest experimental design was chosen to investigate the relationship between baseline measures of HRV (rest; independent variable), myocardial work (rate–pressure product (RPP)), mean arterial pressure (MAP) and aerobic performance parameters. The study participants were eight local female schoolteachers aged 54.1 ± 6.5 years (mean ± SD), with a body mass of 70.6 ± 11.5 kg and a height of 164.5 ± 6.5 cm. Their HRV data were analyzed in R package, and the Bayesian estimation of correlation was calculated employing the Bayesian hierarchical model that uses MCMC simulation integrated in the JAGS package. Results: The Bayesian estimation of correlation using MCMC simulation reproduced and supported the findings reported regarding norms and the within-HRV-indices associations. The results of the Bayesian estimation showed a possible association (regardless of the strength) between pNN50% and MAP (rho = 0.671; 95% HDI = 0.928–0.004), MeanRR (ms) and RPP (rho = −0.68; 95% HDI = −0.064–−0.935), SDNN (ms) and RPP (rho = 0.672; 95% HDI = 0.918–0.001), LF (ms²) and RPP (rho = 0.733; 95% HDI = 0.935–0.118) and SD2 and RPP (rho = 0.692; 95% HDI = 0.939–0.055). Conclusions: The Bayesian estimation of correlation with 95% HDI on MCMC simulated data is a new technique for data analysis in sport science and seems to provide a more robust approach to allocating credibility through a meaningful mathematical model. However, the 95% HDI found in this study, accompanied by the theoretical explanations regarding the dynamics between the parasympathetic nervous system and the sympathetic nervous system in relation to different recording conditions (supine, reactivation, rest), recording systems, time of day (morning, evening, sleep etc.) and age of participants, suggests that the association between measures of HRV indices and aerobic performance parameters has yet to be explicated.

Hemodynamic Adaptations Induced by Short-Term Run Interval Training in College Students

Perceived lack of time is one of the most often cited barriers to exercise participation. High intensity interval training has become a popular training modality that incorporates intervals of maximal and low-intensity exercise with a time commitment usually shorter than 30 min. The purpose of this study was to examine the effects of short-term run interval training (RIT) on body composition (BC) and cardiorespiratory responses in undergraduate college students. Nineteen males (21.5 ± 1.6 years) were randomly assigned to a non-exercise control (CON, n = 10) or RIT (n = 9). Baseline measurements of systolic and diastolic blood pressure, resting heart rate (HRrest), double product (DP) and BC were obtained from both groups. VO_2max and running speed associated with VO_2peak (sVO_2peak) were then measured. RIT consisted of three running treadmill sessions per week over 4 weeks (intervals at 100% sVO_2peak, recovery periods at 40% sVO_2peak). There were no differences in post-training BC or VO₂max between groups (p > 0.05). HRrest (p = 0.006) and DP (p ≤ 0.001) were lower in the RIT group compared to CON at completion of the study. RIT lowered HRrest and DP in the absence of appreciable BC and VO_2max changes. Thereby, RIT could be an alternative model of training to diminish health-related risk factors in undergraduate college students.

Myocardial oxygen consumption in the bed bath and shower bath in patients with acute coronary syndrome

BACKGROUND

Bed and shower hygiene measures are performed by the nursing staff in patients admitted with Acute Coronary Syndrome (ACS). Few studies have evaluated the difference in energy consumption between the two types of bath.

OBJECTIVES

To analyse and compare the variation in Heart Rate (HR), Systolic Blood Pressure (SBP) and rate-pressure-product (RPP) between bed and shower bath in ACS patients.

DESIGN

Quantitative, analytical, prospective study.

SETTINGS

This study was conducted in a Coronary Intensive Care Unit, including patients over 18 years admitted for ACS in Killip classes I and II.

MAIN OUTCOME MEASURES

The level of myocardial oxygen consumption was assessed by calculating the RPP before, immediately after and 5 minutes after the first bed bath and the first shower bath. Differences in mean RPP before, during and 5 minutes after each body hygiene were compared using the paired-samples Student's t-test.

RESULTS

Seventy patients were included. No important clinical variation was found in HR, SBP and RPP during bed bath and during shower bath. The comparison of HR, SBP and RPP between bed bath and shower showed no statistically significant difference.

CONCLUSION

Bed bath and shower bath did not significantly increase energy expenditure in patients with acute coronary syndrome and there was no difference in energy expenditure between the two types of body hygiene.

Exercise-based cardiac rehabilitation for postcoronary artery bypass grafting and its effect on hemodynamic responses and functional capacity evaluated using the Incremental Shuttle Walking Test: A retrospective pilot analysis

BACKGROUND

Coronary artery bypass grafting (CABG) is a common surgical procedure for the restoration of blood flow into stenotic or blocked coronary arteries. Cardiac rehabilitation has been implemented to some extent worldwide for the management of postoperative CABG. However, studies about the effect of exercise training on hemodynamic responses of the heart using the Incremental Shuttle Walking (ISWT) test are limited in Saudi Arabia.

OBJECTIVES

To investigate the effect of exercise-based cardiac rehabilitation (Phase 3, hospital-based) on some hemodynamic responses including blood pressure, heart rate (HR) and heart rate recovery (HRR), and rate pressure product (RPP) using ISWT on post-CABG patients.

METHODS

Fifteen CABG (51.4 ± 6.4 years, 14 male, 1 female) patients without altering their medication were enrolled in a hospital-based cardiac rehabilitation program (Phase 3) between 2011 and 2012 for supervised individual exercise training sessions (three times per week for 8 weeks; 60-minute session at a moderate intensity). Patients performed two tests (ISWT1 and ISWT2) and one before exercise training program and one after, during which resting systolic blood pressure (SBP) and diastolic blood pressure (DBP), post-ISWT SBP and DBP, resting HR, peak HR, HRR (which was defined as the absolute change from peak HR to 1-minute post peak HR), and RPP at rest and at the end of the ISWT were measured. Exercise training sessions included both aerobic and resistance exercises, which were preceded by a cooling down period and followed by a recovery period.

RESULTS

Paired t-test showed a significant reduction in both resting SBP (p = 0.04) and DBP (p = 0.03), and a significant increase in post-ISWT2 SBP (p = 0.004), peak HR (p = 0.003), HRR (p = 0.03), and RPP at maximum (p = 0.002) after 8 weeks of supervised exercise training. In addition, there was a significant increase in the speed and distance achieved on ISWT2 (p < 0.001) after the training program.

CONCLUSION

Supervised exercise training (cardiac rehabilitation) for 8 weeks was effective in improving hemodynamic responses and functional exercise capacity in CABG patients. Cardiac rehabilitation should be implemented more frequently and health-care providers should be aware of its importance. Further research is needed in this area to confirm these findings in the region.

Effects of Exercise Training With and Without Ranolazine on Peak Oxygen Consumption, Daily Physical Activity, and Quality of Life in Patients With Chronic Stable Angina Pectoris

Ranolazine reduces angina frequency and increases exercise capacity. We hypothesized that exercise training with ranolazine would allow subjects to train at greater intensities, resulting in greater improvements in exercise capacity, physical activity, and health-related quality of life (HRQOL). In a pilot study, subjects with chronic stable angina pectoris were randomized to ranolazine (n = 13) or placebo (n = 16). After a 2-week drug titration period, subjects participated in a 12-week exercise program. Peak VO₂, physical activity (via accelerometer), and HRQOL were assessed before and after training. After exercise training, peak VO₂increased twice as much with ranolazine (2.1 ± 3.4 ml/kg/min) as with placebo (0.9 ± 1.5) (both p <0.05). After exercise training, both groups significantly improved HRQOL score (p <0.05); however, the improvement with ranolazine (19 ± 21) was almost 50% greater than with placebo (13 ± 18). There was a significant decrease in maximal heart rate after training with ranolazine but not with placebo (group difference, p = 0.04). Oxygen pulse (peak VO₂/peak HR) increased in both groups after training; but, the increase was 4 times greater with ranolazine - resulting in a significant difference between groups (p = 0.044). In conclusion, patients with angina, the addition of ranolazine to an exercise program may improve aerobic fitness, physical activity, and HRQOL beyond the results of an exercise training program alone. Exercise training with ranolazine led to significantly greater increases in oxygen pulse, which is significantly correlated with stroke volume and is an independent predictor of mortality.

Short-term high-Intensity interval training increases systemic brain-derived neurotrophic factor (BDNF) in healthy women

BACKGROUND

Brain-derived neurotrophic factor (BDNF) increases neuronal viability and cognitive function, peripheral lipid metabolism and skeletal muscle repair. The primary purpose of this study was to determine the effect of short-term high-intensity interval training (HIIT) on serum BDNF concentrations in healthy young women.

METHODS

Seventeen women (age:22 ± 1 years); body mass index (BMI:24.2 ± 2.2 kg/m²), body fat percentage (% fat:25.8 ± 4.7) participated in the study. Participants were randomly assigned to a control (n = 8) or HIIT group (n = 9). All participants performed a graded exercise test (GXT) on an electronically-braked cycle ergometer to determine maximal aerobic power (MAP, Watts). HIIT was performed three days per week for four weeks. Each HIIT session consisted of three to five cycling bouts of 30 s each at 80% MAP, followed by four-minutes of recovery at 40% MAP. Forty-eight hours after the last bout of exercise, both groups performed a follow-up GXT. Non-fasting blood samples were collected before and immediately after each GXT. Mixed factorial (2 groups x 4 measures, and 2 groups x 2 measures) ANOVA was used to assess BDNF concentrations, performance and anthropometric variables.

RESULTS

Serum BDNF concentrations in the HIIT group (21.9 ± 1.3 ng/mL) increased compared to control (19.2 ± 2.8 ng/mL) (∼12%, P < 0.05) following HIIT. In contrast, circulating BDNF concentrations were reduced following the GXT (P < 0.05). The MAP and % Fat did not change with HIIT.

CONCLUSIONS

Twelve sessions of HIIT increases circulating BDNF concentrations in healthy young women despite no change in physical performance or % fat.

Analysis of Exercise Capacity of Children with Kawasaki Disease by a Coronary Artery z Score Model (ZSP Version 4) Derived by the Lambda-Mu-Sigma Method

OBJECTIVE

To compare exercise capacity measured by direct cardiopulmonary exercise testing (CPET) of children with Kawasaki disease with different coronary artery diameter z scores (CA z score).

STUDY DESIGN

This was a retrospective study that recruited children with Kawasaki disease after the acute stage receiving CPETs determined by CPET with treadmill. CA z score was based on a model using the Lambda-Mu-Sigma method. Max-Z was defined as the maximum z score of the proximal left anterior descending CA (LCA) or right CA (RCA). Children with Kawasaki disease with a Max z <2.0 and ≥2.0 were defined as Kawasaki disease group 1 and Kawasaki disease group 2, respectively.

RESULTS

We recruited 32 boys and 17 girls with a mean age of 12.39 ± 3.61 years. Kawasaki disease group 1 (n = 36) had significantly higher peak metabolic equivalent (peak-MET) and peak rate pressure product (PRPP) than Kawasaki disease group 2 (n-13) (P = .046, P < .001). Max-Z correlated with peak-MET moderately and negatively (P < .001, Spearman rho= - .506). Max-Z correlated with PRPP modestly and negatively (P = .011, Spearman rho= - .360).

CONCLUSIONS

Children after Kawasaki disease with a coronary artery Max-Z ≥ 2.0 had significantly lower peak exercise capacity than those with a Max-Z < 2.0. Max-Z might be used as an indicator of CA reserve and exercise capacity during peak exercise after the acute stage of Kawasaki disease.

The Importance of the Double Product in the Six-Minute Walk Test to Predict Myocardial Function

Introduction

The Six-Minute Walk Test (6MWT) is a widely used test to measure the physical performance of patients to assess the effectiveness of treatment, to qualify for rehabilitation, and to evaluate its effects..

Aim

This paper focuses on the assessment of the growth of a double product (DP) during the 6MWT and its diagnostic value in the assessment of patients with heart failure.

Material and Methods

The paper has retrospective character. We analyzed medical records of 412 patients hospitalized for cardiac reasons, in whom a 6MWT was performed. The patients were divided into two groups: one with diagnosed heart failure and a control group.

Results

The patients with diagnosed heart failure, compared to the control group, were characterized by a shorter walking distance and greater DP increase at equal walking intervals. After distinguishing the group with the preserved and decreased left ventricle ejection fraction, the value of the DP increase was still higher compared to the control group. The mean DP increase corresponding to one meter of walk was the only one that correlated negatively with the left ventricular ejection fraction.

Conclusion

The assessment of the increase of the DP during the march test seems to be a better parameter reflecting the efficiency of the myocardium from the distance of the march.

Acute effect of moderate-intensity concentric and eccentric exercise on cardiac effort, perceived exertion and interleukin-6 level in physically inactive males

BACKGROUND

Muscle-derived interleukin-6 (IL-6) not only enhances glucose and fat metabolism but also has an anti-inflammatory effect that can prevent the development of cardiovascular disease (CVD) and metabolic syndrome. Dynamic resistance exercise comprises a muscle shortening and a lengthening phase known as concentric and eccentric contraction respectively. We compared an acute bout of concentric exercise (CE) with eccentric exercise (EE) for the serum IL-6 concentration, myocardial oxygen consumption (MVO2) and rating of perceived exertion (RPE).

METHODS

The present non-randomized crossover study involved 24 physically inactive but apparently healthy males, aged 18-25 years with body mass index of 18.5-23 kg/m2. Each participant performed an acute bout of moderate intensity CE followed by an EE bout after two weeks of rest. Exercise bout lasted for about 45 minutes that involved brisk walking on a treadmill at ±21% gradient for approximately 30 minutes, followed by the dumbbell exercises for biceps, triceps, quadriceps and hamstring muscles. MVO2 and IL-6 were estimated by the rate pressure product (RPP) and ELISA (enzyme-linked immunosorbent assay) kit respectively. Participants told their RPE after the workout. Wilcoxon or paired-t test were applied appropriately to compare the means. P<0.05 was considered significant.

RESULTS

RPP, RPE, and serum IL-6 levels were significantly lower after EE (164.4±16.3, 12, and 1.1±0.5, respectively) than CE (191.2±22.9, 13, and 1.2±0.6, respectively). A significant, strong and positive correlation of RPE was obtained with post-exercise heart-rate and RPP.

CONCLUSIONS

Regular EE might be beneficial for individuals having a low tolerance to exertion or at risk of developing CVD.

L-carnitine reduces susceptibility to bupivacaine-induced cardiotoxicity: an experimental study in rats

BACKGROUND

The primary aim of this study was to evaluate the effect of acute administration of L-carnitine 100 mg·kg^-1 iv on susceptibility to bupivacaine-induced cardiotoxicity in rats.

METHODS

In the first of two experiments, L-carnitine 100 mg·kg^-1 iv (n = 10) or saline iv (n = 10) was administered to anesthetized and mechanically ventilated Sprague-Dawley rats following which an infusion of bupivacaine 2.0 mg·kg^-1·min^-1 iv was given until asystole occurred. The primary outcome was the probability of survival. Secondary outcomes included times to asystole, first dysrhythmia, and to 50% reductions in heart rate (HR) and mean arterial pressure (MAP). To determine whether the same dose of L-carnitine is effective in treating established bupivacaine cardiotoxicity, we also conducted a second experiment in which bupivacaine 20 mg·kg^-1 iv was infused over 20 sec. Animals (n = 10 per group) received one of four iv treatments: 30% lipid emulsion 4.0 mL·kg^-1, L-carnitine 100 mg·kg^-1, 30% lipid emulsion plus L-carnitine, or saline. The primary outcome was the return of spontaneous circulation (ROSC) during resuscitation.

RESULTS

In the first study, L-carnitine 100 mg·kg^-1 increased the probability of survival during bupivacaine infusion (hazard ratio, 12.0; 95% confidence interval, 3.5 to 41.5; P < 0.001). In L-carnitine-treated animals, the times to asystole, first dysrhythmia, and to 50% reductions in HR and MAP increased by 33% (P < 0.001), 65% (P < 0.001), 71% (P < 0.001), and 63% (P < 0.001), respectively. In the second study, no animal in the control or L-carnitine alone groups achieved ROSC when compared with the lipid emulsion groups (P < 0.01).

CONCLUSION

These findings suggest that acute administration of L-carnitine 100 mg·kg^-1 decreases susceptibility to bupivacaine cardiotoxicity, but is ineffective during resuscitation from bupivacaine-induced cardiac arrest.

Cardiopulmonary Function, Exercise Capacity, and Echocardiography Finding of Pediatric Patients With Kawasaki Disease: An Observational Study

Coronary artery (CA) abnormalities influence exercise capacity (EC) of patients with Kawasaki disease (KD), and Z-score of CA is a well established method for detecting CA aneurysm. We studied the influence of KD on cardiopulmonary function and EC; meanwhile we analyzed echocardiographic findings of KD patients. We also assessed the correlation between CA Z-score and EC of KD patients to see if CA Z-score of KD patients could reflect EC during exercise.Sixty-three KD patients were recruited as KD group 1 from children (aged 5-18 y) who received transthoracic echocardiographic examinations and symptom-limited treadmill exercise test for regular follow-up of KD from January 2010 to October 2014 in 1 medical center. We then divided KD group 1 into KD group 2 (<5 y, n = 12) and KD group 3 (≥5 y, n = 51) according to time interval between KD onset to when patients received test. Control groups were matched by age, sex, and body mass index. Max-Z of CA was defined as the maximal Z-score of the proximal LCA or RCA by Dalliarre equation or Fuse calculator.All routine parameters measured during standard exercise test were similar between KD and control groups, except that peak rate pressure products (PRPPs) in KD group 1 to 3 were all lower than corresponding control groups significantly (P = 0.010, 0.020, and 0.049, respectively). PRPPs correlated with Max-Z of CA by both equations modest inversely (by Dallaire, P = 0.017, Spearman rho = -0.301; by Fuse, P = 0.014, Spearman rho = -0.309).Our study recruited larger number of KD patients and provided a newer data of EC of KD patients. Our finding suggests that after acute stage of KD, patients could maintain normal cardiorespiratory fitness. Therefore, we believe that it is important to promote cardiovascular health to KD patients and KD patients should exercise as normal peers. However, since KD patients might still have compromised coronary perfusion during exercise, it remains crucial to assess and monitor cardiovascular risk of KD patients. Max-Z of CA correlates with PRPP modest inversely and might be used as a follow-up indicator of CA reserve during exercise after acute stage of KD.

Natriuretic Peptides as Cardiovascular Safety Biomarkers in Rats: Comparison With Blood Pressure, Heart Rate, and Heart Weight

Cardiovascular (CV) toxicity is an important cause of failure during drug development. Blood-based biomarkers can be used to detect CV toxicity during preclinical development and prioritize compounds at lower risk of causing such toxicities. Evidence of myocardial degeneration can be detected by measuring concentrations of biomarkers such as cardiac troponin I and creatine kinase in blood; however, detection of functional changes in the CV system, such as blood pressure, generally requires studies in animals with surgically implanted pressure transducers. This is a significant limitation because sustained changes in blood pressure are often accompanied by changes in heart rate and together can lead to cardiac hypertrophy and myocardial degeneration in animals, and major adverse cardiovascular events (MACE) in humans. Increased concentrations of NPs in blood correlate with higher risk of cardiac mortality, all-cause mortality, and MACE in humans. Their utility as biomarkers of CV function and toxicity in rodents was investigated by exploring the relationships between plasma concentrations of NTproANP and NTproBNP, blood pressure, heart rate, and heart weight in Sprague Dawley rats administered compounds that caused hypotension or hypertension, including nifedipine, fluprostenol, minoxidil, L-NAME, L-thyroxine, or sunitinib for 1-2 weeks. Changes in NTproANP and/or NTproBNP concentrations were inversely correlated with changes in blood pressure. NTproANP and NTproBNP concentrations were inconsistently correlated with relative heart weights. In addition, increased heart rate was associated with increased heart weights. These studies support the use of natriuretic peptides and heart rate to detect changes in blood pressure and cardiac hypertrophy in short-duration rat studies.

The effects of high-intensity intermittent exercise training on cardiovascular response to mental and physical challenge

The purpose was to examine the effect of a 12-week exercise intervention on the cardiovascular and autonomic response of males to mental and physical challenge. Thirty four young overweight males were randomly assigned to either an exercise or control group. The exercise group completed a high-intensity intermittent exercise (HIIE) program three times per week for 12weeks. Cardiovascular response to the Stroop task was determined before and after the intervention by assessing heart rate (HR), stroke volume (SV), arterial stiffness, baroreflex sensitivity (BRS), and skeletal muscle blood flow. The exercise group improved their aerobic fitness levels by 17% and reduced their body weight by 1.6kg. Exercisers compared to controls experienced a significant reduction in HR (p<0.001) and a significant increase in SV (p<0.001) at rest and during Stroop and exercise. For exercisers, arterial stiffness significantly decreased at rest and during Stroop (p<0.01), whereas BRS was increased at rest and during Stroop (p<0.01). Forearm blood flow was significantly increased during the first two minutes of Stroop (p<0.05). HIIE induced significant cardiovascular and autonomic changes at rest and during mental and physical challenge after 12weeks of training.