An update on exercise stress testing

Association of abnormalities in electrocardiography and ultrasonic echocardiography with the occurrence of cardiovascular disease in patients with advanced chronic kidney disease

BACKGROUND

In patients with chronic kidney disease (CKD), the incidence of cardiovascular disease (CVD) increases with disease progression. CVD screening tests in those with CKD were researched to determine whether abnormalities observed in electrocardiography (ECG) and ultrasonic echocardiography (UCG) were risk factors associated with the development of CVD.

METHODS

This study included 604 patients with CKD G4 and G5, for whom both ECG and UCG were performed. They were divided into four groups: those without ECG- and UCG-indicated abnormalities (group A, n = 333), with only ECG abnormalities (group B, n = 106), with only UCG abnormalities (group C, n = 75), and with both ECG and UCG abnormalities (group D, n = 90). Multivariate analysis using Cox regression analysis of the occurrence of CVD was performed during a follow-up period.

RESULTS

During the observation period, 124 patients had clinical events. Among them, 45 patients (13.5%) were in Group A, 25 patients (23.6%) in Group B, 19 patients (25.3%) in Group C, and 35 patients (38.9%) in Group D, respectively. CVD event occurrence was highest in Group D. The results of the multivariate analysis also showed that the CVD event rates were significantly higher in Group C (HR: 2.96, P = < .001) and D (HR: 4.22, P < .001) than in Group A.

CONCLUSION

In patients with advanced CKD, there was a significant correlation of ECG and UCG abnormalities with CVD events. Additionally, those having both types of abnormalities may have a higher risk of coronary artery disease than other groups.

Sixty years of the Bruce protocol: reappraising the contemporary role of exercise stress testing with electrocardiographic monitoring

The cardiovascular response to exercise has long been a focus of interest. Over a century ago, the first descriptions of electrocardiographic changes occurring during exercise highlighted the possible relevance of this dynamic assessment. In this background, the inception of the Bruce protocol circa 60 years ago allowed for a major leap in this field by providing a standardized framework with which to address this issue, by means of an integrated and structured methodology. Since then, exercise stress testing with electrocardiographic monitoring (ExECG) has become one of the most widely appraised tests in cardiovascular medicine. Notably, past few decades have been profoundly marked by substantial advances in the approach to cardiovascular disease, challenging prior notions concerning both its physiopathology and overall management. Among these, the ever-evolving presentations of cardiovascular disease coupled with the development and implementation of several novel diagnostic modalities (both invasive and noninvasive) has led to a shifting paradigm in the application of ExECG. This technique, however, has continuously shown to be of added value across various momentums of the cardiovascular continuum, as depicted in several contemporary guidelines. This review provides a pragmatical reflexion on the development of ExECG, presenting a comprehensive overview concerning the current role of this modality, its challenges, and its future perspectives.

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

BACKGROUND

Heart rate recovery (HRR) in the exercise test is the index of cardiac autonomic system function and sympathovagal balance impaired in patients with myocardial infarction (MI). An instance is left atrial (LA) phasic function, which is impaired in such patients. In this study, we investigated the role of HRR in predicting LA phasic functions in patients with MI.

METHODS

The present study recruited 144 consecutive patients with ST-elevation MI. A symptom-limited exercise test was performed about 5 weeks after MI, with echocardiography conducted just before the exercise test. The patients were divided into abnormal and normal HRR at 60 s (HRR60) and again into abnormal and normal HRR at 120 s (HRR120) after the exercise test. LA phasic functions, evaluated by 2D speckle-tracking echocardiography, were compared between the 2 groups.

RESULTS

Patients with abnormal HRR120 had lower LA strain values and strain rates during the reservoir, conduit, and contraction phases, while those with abnormal HRR60 had lower LA strain values and strain rates during the reservoir and conduit phases. The differences were lost after adjustments for possible confounders, except for LA strain and strain rate during the conduit phase, in patients with abnormal HRR120.

CONCLUSIONS

Abnormal HRR120 in the exercise test can independently predict decreased LA conduit function in patients with ST-elevation MI.

The Autonomic Imbalance of Myocardial Ischemia during Exercise Stress Testing: Insight from Short-Term Heart Rate Variability Analysis

Exercise stress testing (EST) has limited power in diagnosing obstructive coronary artery disease (CAD). The heart rate variability (HRV) analysis might increase the sensitivity of CAD detection. This study aimed to evaluate the correlation between short-term HRV and myocardial ischemia during EST, including the acceleration, maximum, and recovery stages of heart rate (HR). The HRV during EST from 19 healthy (RHC) subjects and 35 patients with CAD (25 patients with insignificant CAD (iCAD), and 10 patients with significant CAD (sCAD)) were compared. As a result, all HRV indices decreased at the maximum stage and no significant differences between iCAD and sCAD were found. The low-frequency power of heart rate signal (LF) of the RHC group recovered relatively quickly from the third to the sixth minutes after maximum HR, compared with that of the sCAD group. The relative changes of most HRV indices between maximum HR and recovery stage were lower in the sCAD group than in the RHC group, especially in LF, the standard deviation of all normal to normal intervals (SDNN), and the standard deviation in the long axis direction of the Poincaré plot analysis (SD2) indices (p < 0.05). The recovery slope of LF was significantly smaller in the sCAD group than in the RHC group (p = 0.02). The result suggests that monitoring short-term HRV during EST provides helpful insight into the cardiovascular autonomic imbalance in patients with significant CAD. The relative change of autonomic tone, especially the delayed sympathetic recovery, could be an additional marker for diagnosing myocardial ischemia.

Heart Rate Response to Exercise and Recovery: INDEPENDENT PROGNOSTIC MEASURES IN PATIENTS WITHOUT KNOWN MAJOR CARDIOVASCULAR DISEASE

PURPOSE

Heart rate response during exercise testing (ET) provides valuable prognostic information. Limited data are available regarding the prognostic interplay of heart rate (HR) measured at rest, exercise and recovery phases of ET, and its ability to predict risk beyond exercise capacity.

METHODS

Retrospective analysis of treadmill ETs was performed by the Bruce protocol in patients aged 35-75 yr without known cardiovascular disease (CVD; n = 13 887; 47% women). Heart rate recovery at 2 min (HRR2; defined abnormal <42 beats) and chronotropic index (CI; defined abnormal <80%, determined as age-predicted HR reserve) were analyzed in association with the risk of developing myocardial infarction, stroke, or death (major adverse cardiovascular event [MACE]) during median follow-up of 6.5 yr.

RESULTS

The HRR2 <42 beats and CI <80% were each associated with increased risk of MACE: adjusted hazard ratios with 95% confidence interval 1.47: 1.27-1.72 and 1.66: 1.42-1.93, P < .001, respectively, evident also when analyzed as continuous variables. Strength of association of HRR2 and CI with outcome was attenuated but remained significant with further adjustment for exercise duration and metabolic equivalents. Having both HRR2 and CI abnormal compared with only one measure abnormal was associated with hazard ratios with 95% confidence interval of 1.66: 1.38-2.00 and 1.48: 1.22-1.79 for MACE, before and after adjustment for cardiorespiratory fitness (CRF). The degree of CRF (low vs mid/high) did not modify the prognostic effect of HRR2 and CI (P-for-interaction nonsignificant).

CONCLUSIONS

Both HRR2 and CI provide independent prognostic information beyond CRF in patients without CVD referred for ET. The predictive ability is more pronounced when both abnormal HR measures coexist.

Blood pressure response during treadmill exercise testing and the risk for future cardiovascular events and new-onset hypertension

OBJECTIVE

The physiologic response to exercise may provide valuable prognostic information. We investigated the association of blood pressure (BP) measurements during exercise stress testing (EST) with long-term risk of myocardial infarction, stroke or death (major adverse cardiovascular event, MACE), as well as the development of new-onset hypertension.

METHODS

A retrospective analysis of treadmill ESTs (years 2005-2019) performed by the Bruce protocol in patients aged 35-75 years without a history of cardiovascular disease (n = 14 792; 48% women). BP was documented at rest, submaximal exercise (Bruce stage-2), peak exercise and recovery (2 min). Association of SBP measures with study outcomes during median follow-up of 6.5 years was investigated.

RESULTS

Highest vs. lowest SBP quartile at rest (≥140 vs. <120 mmHg), submaximal-exercise (≥170 vs. <130 mmHg), peak-exercise (≥180 vs. ≤145 mmHg) and recovery (≥160 vs. <130 mmHg) was associated with an increase in the adjusted hazard ratio and 95% confidence interval (CI) for MACE: 1.53 (1.23-1.88), 1.33 (1.01-1.76), 1.30 (1.05-1.61), 1.35 (1.09-1.68), respectively. The association between SBP at submaximal exercise and recovery with MACE displayed a J-shaped pattern. Among nonhypertensive patients (n = 8529), excessive SBP response to peak exercise (≥190 mmHg in women and ≥210 mmHg in men) was an independent predictor of hypertension [hazard ratio (95% CI)]: 1.87 (1.41-2.48), as were SBPs during submaximal exercise [>160 vs. ≤130 mmHg: 2.44 (1.97-3.03)] and recovery [≥140 vs. ≤120 mmHg: 1.65 (1.37-1.98)].

CONCLUSION

BP measurement during rest, exercise and recovery phases of EST provides incremental prognostic information regarding long-term risk for cardiovascular events and the probability for developing hypertension.

Italian Cardiological Guidelines (COCIS) for Competitive Sport Eligibility in athletes with heart disease: update 2020

Since 1989, SIC Sport and a FMSI, in partnership with leading Italian Cardiological Scientific Associations (ANCE, ANMCO and SIC) have produced Cardiological Guidelines for Completive Sports Eligibility for athletes with heart disease (COCIS -- 1989, 1995, 2003, 2009 and 2017). The English version of the Italian Cardiological Guidelines for Competitive Sports Eligibility for athletes with heart disease was published in 2013 in this Journal. This publication is an update with respect to the document previously published in English in 2013. It includes the principal innovations that have emerged over recent years, and is divided into five main chapters: arrhythmias, ion channel disorders, congenital heart diseases, acquired valve diseases, cardiomyopathies, myocarditis and pericarditis and ischemic heart disease. Wherever no new data have been introduced with respect to the 2013 publication, please refer to the previous version. This document is intended to complement recent European and American guidelines but an important difference should be noted. The European and American guidelines indicate good practice for people engaging in physical activity at various levels, not only at the competitive level. In contrast, the COCIS guidelines refer specifically to competitive athletes in various sports including those with high cardiovascular stress. This explains why Italian guidelines are more restrictive than European and USA ones. COCIS guidelines address 'sports doctors' who, in Italy, must certify fitness to participate in competitive sports. In Italy, this certificate is essential for participating in any competition.

Exercise capacity in axial spondyloarthritis and associated factors: A cross-sectional controlled study

OBJECTIVE

To examine the associations between exercise capacity (EC), cardiovascular (CV) risk factors and disease-related variables in axial spondyloarthritis (AxSpA) patients.

METHODS

In this cross-sectional controlled study, CV risk profile data, physical activity, 10-year CV event risk estimated by the Framingham model and Ankylosing Spondylitis Disease Activity Score - C-reactive protein were recorded. A maximal treadmill exercise test by Bruce protocol was administered. Analyses of covariance were performed with adjustments for age, smoking status and physical activity level. Linear regression analysis was performed to study the association between EC and related CV risk factors.

RESULTS

Thirty-eight patients and 38 age-gender matched controls were recruited between May and October 2014. Patients had significantly lower EC than controls (MD 2.2; metabolic equivalents 0.91-3.49; P = .001). The difference remained significant after adjustments (P = .001). There were significant correlations between EC and age, 10-year CV event risk, body mass index (BMI) and waist circumference for patients and controls (P < .001 and P < .05, respectively). There was a significant relationship between EC and total cholesterol, triglycerides and heart rate recovery (HRR) in patients (P = .04, P < .001 and P = .006, respectively). High-density lipoprotein - cholesterol was significantly higher, and BMI was significantly lower in nonradiographic AxSpA patients (P = .026 and P = .03 respectively). Age and triglyceride levels were found as the significant predictors for EC in the AxSpa group (for age β = -.105, P = .003; for triglycerides β = -.016 P = .003).

CONCLUSION

Exercise capacity was significantly lower and attenuated HRR was significantly associated with low EC and high 10-year CV event risk in AxSpA patients.

Correlation Between the 6-Min Walk Test and Exercise Tolerance Test in Cardiac Rehabilitation After Coronary Artery Bypass Grafting: A Cross-sectional Study

Introduction

Exercise capacity and quality of life are the main outcomes in cardiac rehabilitation (CR). Exercise capacity is one of the important prognostic and diagnostic measures acquired by the exercise tolerance test (ETT). The 6-min walk test (6MWT), as a functional walking test, is another tool for assessing exercise capacity.

Methods

Eighty postoperative coronary artery bypass grafting (CABG) participants admitted to three CR units were recruited for this cross-sectional and multicenter study, based on convenient non-probability sampling. All participants performed an ETT and two repeated 6MWTs. Maximum heart rate (HR), maximum blood pressure (BP), maximal oxygen uptake (VO2_max), and peak metabolic equivalents of tasks (MET) during the tests and also the 6-min walk distance (6MWD) were the outcome measures.

Results

The mean age of all participants was 62.13 (7.12) years and 80% were male. Pearson correlation showed that maximum HR (r(78) = 0.67, P < 0.001) and maximum systolic BP (r(78) = 0.57, P < 0.001) during the 6MWT correlated moderately with those achieved during ETT. Maximum HR in the 6MWT corresponded to 86% of that achieved during ETT. The 6MWD showed a strong positive correlation with peak MET estimated during ETT as a measure of exercise capacity (r = 0.77, P < 0.001).

Conclusions

The results from this study suggest that the 6MWT is a valid tool for assessing functional capacity for prescribing exercise in a group of postoperative CABG participants admitted to CR units. This finding is helpful for healthcare professionals and for patients, as the test is easy to administer and also well tolerated by patients.

Trial Registration Number

PHT-9923.

Severity, Progress, and Related Factors of Mood Disorders in Patients with Coronary Artery Disease: A Retrospective Study

Patients with coronary artery disease (CAD) are more likely to experience depression and anxiety, which, in turn, are risk factors for CAD. The Beck depression inventory (BDI) and Beck anxiety inventory (BAI) were applied for mood evaluation during hospitalization and again 3 months after discharge in 118 patients with CAD, and cardiopulmonary exercise tests were conducted in the outpatient department. Of the patients diagnosed with CAD, 40 (33.9%) had depressive moods, and 51 (43.2%) had anxious moods. A family history of CAD, low Korean activity scale index (KASI), and use of beta-blockers were independent factors causing depressive mood, while lower left ventricular ejection fraction (LVEF) and low KASI score were independent factors causing anxious mood. A considerable number of patients (35.7% with depressive mood and 25.0% with anxious mood) still had emotional problems after 3 months of discharge. The change values of BDI were associated with lower LVEF and longer hospital stay, while those of BAI was associated with a longer hospital stay. Since some patients had depressive and anxious moods after three months of discharge, evaluating and treating them are essential.

Does Ramadan Observance Affect Cardiorespiratory Capacity of Healthy Boys?

Studies raising the issue of the effects of Ramadan observance (RO) on boys' 6-min walk test (6MWT) data are rare. The studies, which did not include control groups of non-fasters, presented contradictory results. This study aimed to compare the 6MWT data (6-min walk distance [6MWD; m, %predicted], heart rate [HR; bpm, % of maximal predicted HR]), oxy-hemoglobin saturation (Oxy-sat; %), systolic and diastolic blood pressures (SBP and DBP, respectively; mmHg) determined at rest (_Rest and at the end _End of the test) of a group of 22 healthy fasting boys (age: 12 to 15 years) with an age-matched non-fasting group (n = 10). The 6MWTs were performed during three experimental conditions (ECs): Pre-Ramadan, Mid-Ramadan, and Post-Ramadan. The two groups' 6MWT data for each EC were compared, and repeated factorial analysis of variance (2 groups vs. 3 ECs) was performed. Both groups had similar values of 6MWD (m, %predicted), HR_Rest or HR_End (bpm, % of maximal predicted HR), Oxy-sat_Rest, Oxy-sat_End, SBP_Rest, and DBP_Rest during the three ECs. Compared to the non-fasting group, the fasting group had significantly higher SBP_End (121 ± 10 vs. 130 ± 11) and DBP_End (72 ± 6 vs. 78 ± 7) determined during the Mid-Ramadan EC. No significant interactive effects of the groups (2) vs. ECs (3) was found for the 6MWD (%predicted; p = .809), HR_Rest (%, p = .555), HR_End (%, p = .964), Oxy-sat_Rest (p = .336), Oxy-sat_End (p = .389), SBP_Rest (p = .708), SBP_End (p = .548), DBP_Rest (p = .277), and DBP_End (p = .096). To conclude, in boys, RO does not impact the 6MWD, HR, or Oxy-sat, but it has minimal impact on the SBP_End and DBP_End.

Metabolite Concentration Changes in Humans After a Bout of Exercise: a Systematic Review of Exercise Metabolomics Studies

Background

Exercise changes the concentrations of many metabolites, which are small molecules (< 1.5 kDa) metabolized by the reactions of human metabolism. In recent years, especially mass spectrometry-based metabolomics methods have allowed researchers to measure up to hundreds of metabolites in a single sample in a non-biased fashion. To summarize human exercise metabolomics studies to date, we conducted a systematic review that reports the results of experiments that found metabolite concentrations changes after a bout of human endurance or resistance exercise.

Methods

We carried out a systematic review following PRISMA guidelines and searched for human metabolomics studies that report metabolite concentrations before and within 24 h after endurance or resistance exercise in blood, urine, or sweat. We then displayed metabolites that significantly changed their concentration in at least two experiments.

Results

Twenty-seven studies and 57 experiments matched our search criteria and were analyzed. Within these studies, 196 metabolites changed their concentration significantly within 24 h after exercise in at least two experiments. Human biofluids contain mainly unphosphorylated metabolites as the phosphorylation of metabolites such as ATP, glycolytic intermediates, or nucleotides traps these metabolites within cells. Lactate, pyruvate, TCA cycle intermediates, fatty acids, acylcarnitines, and ketone bodies all typically increase after exercise, whereas bile acids decrease. In contrast, the concentrations of proteinogenic and non-proteinogenic amino acids change in different directions.

Conclusion

Across different exercise modes and in different subjects, exercise often consistently changes the average concentrations of metabolites that belong to energy metabolism and other branches of metabolism. This dataset is a useful resource for those that wish to study human exercise metabolism.

French Society of Cardiology guidelines on exercise tests (part 1): Methods and interpretation

The exercise test is still a key examination in cardiology, used for the diagnosis of myocardial ischemia, as well as for the clinical evaluation of other heart diseases. The cardiopulmonary exercise test can further define functional capacity and prognosis for any given cardiac pathology. These new guidelines focus on methods, interpretation and indications for an exercise test or cardiopulmonary exercise test, as summarized below. The safety rules associated with the exercise test must be strictly observed. Interpretation of exercise tests and cardiopulmonary exercise tests must be multivariable. Functional capacity is a strong predictor of all-cause mortality and cardiovascular events. Chest pain, ST-segment changes and an abnormal ST/heart rate index constitute the first findings in favor of myocardial ischemia, mostly related to significant coronary artery disease. Chronotropic incompetence, abnormal heart rate recovery, QRS changes (such as enlargement or axial deviations) and the use of scores (based on the presence of various risk factors) must also be considered in exercise test interpretation for a coronary artery disease diagnosis. Arrhythmias or conduction disorders arising during the exercise test must be considered in the assessment of prognosis, in addition to a decrease or low increase in blood pressure during the exercise phase. When performing a cardiopulmonary exercise test, peak oxygen uptake and the volume of expired gas/carbon dioxide output slope are the two main variables used to evaluate prognosis.

Clinical significance of ST depression at exercise stress testing in competitive athletes: usefulness of coronary CT during screening

BACKGROUND

Congenital coronary anomalies (CCAs) and coronary artery disease (CAD) arouse intense scientific and clinical interest in sports medicine and sports cardiology medical communities because of their potential to trigger sudden cardiac death (SCD) in athletes. Exercise stress testing represent the first instrumental assessment to evaluate electrocardiographic changes during effort. Coronary computed tomography angiography (CCTA) is an advanced accurate noninvasive imaging modality for excluding CAD and abnormalities of origin and course of coronary vessels. The aim of this study is to investigate with CCTA the clinical significance of ST depression suggestive for myocardial ischemia during exercise stress testing in athletes and to determine the prevalence of CAD and/or CCAs.

METHODS

Sixty-five consecutive athletes showing electrocardiographic findings positive or equivocal for myocardial ischemia on exercise stress testing during pre-participation screening were investigated with CCTA.

RESULTS

Among the 65 athletes investigated, 36 showed Myocardial Bridge (MB), one showed an anomalous coronary origin and seven showed CAD. Among 36 athletes with MB, 4 were associated with mild coronary artery stenosis. Three athletes with CAD needed percutaneous transluminal coronary angioplasty or coronary artery bypass surgery.

CONCLUSIONS

In competitive athletes even with excellent workload capacities, in absence of cardiomyopathy, the presence of ischemic electrocardiographic abnormalities could be mainly determined by a coronary congenital or acquired pathology. In this population CCTA is a useful imaging modality of choice for the risk stratification and for the diagnostic process, to allow eligible athletes to compete and to follow-up subjects requiring medical surveillance.

Gender aspects on exercise-induced ECG changes in relation to scintigraphic evidence of myocardial ischaemia

BACKGROUND

This retrospective study aimed to determine the diagnostic performance of exercise-induced ST response in relation to findings by myocardial perfusion single photon emission computed tomography (MPS), with focus on gender differences, in patients with suspected or established stable ischemic heart disease.

METHODS

MPS findings of 1 021 patients (518 females) were related to the exercise-induced ST response alone (blinded and unblinded to gender) and ST response together with additional exercise stress test (EST) variables (exercise capacity, blood pressure and heart rate response).

RESULTS

Exercise-induced ischaemia by MPS was found in 9% of females and 23% of males. Diagnostic performance of exercise-induced ST response in relation to MPS findings in females versus males was: sensitivity = 48%,70%; specificity = 67%, 64%; PPV = 13%, 38%; NPV = 93%, 87%. Adding more EST variables to the ST response interpretation yielded in females vs males: sensitivity = 44%, 51%; specificity = 84%, 83%; PPV = 22%, 48% and NPV = 93%, 85%.

CONCLUSIONS

In patients who have performed EST in conjunction with MPS, there is a gender difference in the diagnostic performance of ST response at stress, with a significantly lower PPV in females compared to males. For both genders, specificity can be significantly improved, and a higher PPV can be obtained, while the sensitivity might be compromised by considering more EST variables, in addition to the ST response.

A new scoring system for evaluating coronary artery disease by using blood pressure variability

The aim of this study was to develop a new scoring system using ambulatory blood pressure monitoring (ABPM) to assist in the evaluation of coronary artery disease (CAD). One hundred twenty-five subjects (53.1 ± 9.6 years of age) were included. Pearson's tests were first performed to identify the parameters that correlated with Duke Treadmill Score (DTS). Blood test parameters and blood pressure variability (BPV) measures that were extracted from the ABPM were included. Next, a multiple linear regression analysis was performed to train a new scoring system in the 84 patients from the 125 patients. Then, a correlation analysis was conducted to validate the correlation between the new scoring system and DTS in the remaining 41 subjects. A further correlation analysis was used to verify the clinical value of the new scoring system using ultrasonic cardiogram (UCG) and brachial-ankle pulse wave velocity (baPWV). Our new scoring system, which had a 24.096 - 0.083 × residual standard deviation of night systolic blood pressure (SBP) - 0.130 × age - 0.206 × average real variability of night SBP, was correlated with DTS (r = 0.312, P = 0.047). Moreover, our new scoring system was also correlated with various markers of cardiac function (r = -0.290, P = 0.001; r = -0.262, P = 0.004; r = -0.303, P = 0.001; r = -0.306, P = 0.001, respectively) measured by UCG and with baPWV (r = 0.529, P = 0.001). Furthermore, the r-values for the BPV Score versus the markers were closer to -1 than the corresponding r-values for the Duke Score vs the same parameters. And the differences in r-values between Duke Score and BPV Score were statistically significant (P = 0.022). In conclusion, the new scoring system based on ABPM has potential as a non-invasive tool for evaluating CAD.

Blood Pressure Response to Submaximal Exercise Test in Adults

Background. The assessment of blood pressure (BP) response during exercise test is an important diagnostic instrument in cardiovascular system evaluation. The study aim was to determine normal values of BP response to submaximal, multistage exercise test in healthy adults with regard to their age, gender, and workload. Materials and Methods. The study was conducted in randomly selected normotensive subjects (n = 1015), 512 females and 498 males, aged 18-64 years (mean age 42.1 ± 12.7 years) divided into five age groups. All subjects were clinically healthy with no chronic diseases diagnosed. Exercise stress tests were performed using Monark bicycle ergometer until a minimum of 85% of physical capacity was reached. BP was measured at rest and at peak of each exercise test stage. Results. The relations between BP, age, and workload during exercise test were determined by linear regression analysis and can be illustrated by the equations: systolic BP (mmHg) = 0.346 × load (W) + 135.76 for males and systolic BP (mmHg) = 0.103 × load (W) + 155.72 for females. Conclusions. Systolic BP increases significantly and proportionally to workload increase during exercise test in healthy adults. The relation can be described by linear equation which can be useful in diagnostics of cardiovascular diseases.

Revisiting age-predicted maximal heart rate: Can it be used as a valid measure of effort?

INTRODUCTION

Despite high error ranges, age-predicted maximal heart rate (APMHR) is frequently used to gauge the achievement of adequate effort during an exercise test. The current analysis revisits this issue using the Fitness Registry and the Importance of Exercise: National Database (FRIEND Registry).

METHODS

A total of 4,796 (63% male) apparently healthy subjects underwent a maximal cardiopulmonary exercise test on a treadmill. The mean age, maximal heart rate (HR), and maximal aerobic capacity of the cohort were 43 ± 12 years, 178 ± 15 beats per minute, and 36.1 ± 10.6 mlO2 · kg(-1) · min(-1), respectively. All subjects reached or surpassed a peak respiratory exchange ratio of 1.10. A linear regression equation using age to predict maximal HR was validated in 3,796 subjects and cross-validated in the remaining 1,000 (randomly assigned).

RESULTS

The APMHR equation in the validation cohort was as follows: 209.3 - 0.72(age). The r value and standard error of estimate for this regression was 0.61 (P < .001) and 11.35 beats/min, respectively. A 1-sample t test revealed that the mean difference between actual maximal HR and APMHR was not significantly different from 0 (mean difference = 0.32, P = .43). However, Bland-Altman revealed high limits of agreement (upper 25.31 and lower -24.67) and a significant proportional bias.

DISCUSSION

The APMHR equation derived from this analysis included a large cohort of apparently healthy individuals with maximal exercise effort validated by the criterion standard (ie, peak respiratory exchange ratio). Using APMHR in this capacity should be discouraged, and new approaches to gauging an individual's exercise effort should be explored.

Blood pressure response to exercise in young athletes aged 10 to 18 years

The aim of the study was to determine arterial blood pressure response to exercise in young athletes. The study group comprised 711 young athletes (457 boys, 254 girls) aged 10 to 18 years (mean 13.41 ± 3.12 years) who had been training for an average of 7.62 ± 4.2 h per week for an average of 4.01 ± 2.5 years. Participants with elevated arterial blood pressure above the 90th percentile at rest were excluded from investigation. A symptom-limited, multistage exercise test to exhaustion was performed using a Monark cycle ergometer. Arterial blood pressure was measured with an aneroid manometer in the third minute of each stage of the test. Mean systolic arterial blood pressure during peak exercise was significantly higher in boys than in girls: 183.21 ± 27.97 mm Hg and 170.97 ± 21.4 mm Hg, respectively (p = 0.03). Multivariate linear regression analysis showed that age and workload had significant effects on arterial blood pressure during the test. Systolic arterial blood pressure during the exercise can be described with the following equations: boys, SBPex (mm Hg) = -1.92 × age (years) + 0.55 × workload (W) + 120.84; girls, SBPex (mm Hg) = -0.88 × age (years) + 0.48 × workload (W) + 111.22. The study results describe reference values of arterial blood pressure during the exercise test. The presented equations and figures can help to assess whether the arterial blood pressure at each stage of the exercise test exceeds the normal range or not.

Approach to assessing determinants of glucose homeostasis in the conscious mouse

Obesity and type 2 diabetes lessen the quality of life of those afflicted and place considerable burden on the healthcare system. Furthermore, the detrimental impact of these pathologies is expected to persist or even worsen. Diabetes is characterized by impaired insulin action and glucose homeostasis. This has led to a rapid increase in the number of mouse models of metabolic disease being used in the basic sciences to assist in facilitating a greater understanding of the metabolic dysregulation associated with obesity and diabetes, the identification of therapeutic targets, and the discovery of effective treatments. This review briefly describes the most frequently utilized models of metabolic disease. A presentation of standard methods and technologies on the horizon for assessing metabolic phenotypes in mice, with particular emphasis on glucose handling and energy balance, is provided. The article also addresses issues related to study design, selection and execution of metabolic tests of glucose metabolism, the presentation of data, and interpretation of results.

Heart rate recovery after the 10-m incremental shuttle walking test in older adults with intellectual disabilities

Heart rate recovery (HRR) after exercise is an independent predictor for cardiovascular and all-cause mortality. To investigate the usefulness of HRR in cardiorespiratory exercise testing in older adults with intellectual disabilities (ID), the aims of this study were (a) to assess HRR in older adults with ID after the 10-m incremental shuttle walking test (ISWT) and (b) its association with personal characteristics (gender, age, distance walked on the ISWT, level of ID, genetic syndrome causing ID, autism, behavioral problems, and peak heart rate (HRpeak)). HRR was assessed after the 10-m incremental shuttle walking test in 300 older adults (>50 years) with borderline to profound ID. HRR was defined as the change from HRpeak during the ISWT to heart rate measured after 1, 2, 3, 4, and 5 min of passive recovery. The largest decrease in heart rate was in the first minute of recovery leveling off toward the fifth minute of recovery. An abnormal HHR (≤12 bpm) was seen in 36.1% of the participants with Down syndrome (DS) and in 30.7% of the participants with ID by other causes. After the fifth minute the heart rates of 69.4% of the participants with DS and of 61.4% of the participants with ID by other causes returned to resting levels. HRpeak and distance walked on the ISWT were positively related to all HRR measures. More severe ID was negatively related and having DS positively related to HRR after 3-5 min of recovery. The other characteristics were not significantly associated to HRR. HRR is a potentially useful outcome measure in cardiorespiratory fitness testing of older adults with ID with a direct, objective, and non-invasive measurement. Further research is needed to identify the relation between HRR and adverse health outcomes in this population.

Exercise electrocardiogram testing in two brothers with different outcome - a case study exercise testing in master cyclists

The cases of two brothers training and competing as master cyclists and both preparing for a cycling tour are presented. The older brother aged 66 years went first to the primary care physician and presented with an asymptomatic depression in the exercise stress test of the ST segment in V5 and V6 during recovery after complete exhaustion. Coronary angiography revealed a multi vessel coronary artery disease and he underwent bypass surgery. One year later, he successfully completed his planned cycling tour of ~600 km in seven stages and covering ~12,000 m of total ascent. The younger brother aged 59 years went a few months later to the primary care physician and also performed asymptomatic exercise stress testing without changes in the ST segments. Unfortunately, 2 months later he suffered a cardiac arrest during his cycling tour and survived following immediate successful cardiopulmonary resuscitation on the road by his cycling colleagues. Immediate invasive coronary arteriography showed a complete stenosis of the trunk of arteria coronaria sinistra (left coronary artery), a 40%-50% stenosis of ramus circumflexus, and a 20% stenosis of arteria coronaria dextra (right coronary artery). The left coronary artery was dilated and he continued cycling 2 months later. In both brothers, familial hypercholesterolemia was the main cardiovascular risk factor for the multi vessel coronary artery disease. A negative exercise electrocardiogram in siblings with an increased risk for coronary artery disease seemed not to exclude an advanced multi vessel coronary artery disease. In master athletes with asymptomatic exercise electrocardiogram but a positive family history, further examinations should be performed in order to detect relevant stenosis in coronary arteries.

Cutaneous microvascular functional assessment during exercise: a novel approach using laser speckle contrast imaging

Cardiovascular diseases are often revealed during exercise and are associated with cutaneous blood flow (CBF) dysfunction. Studies of CBF during exercise are consequently of interest. Laser speckle contrast imaging (LSCI) allows for non-contact and real-time recording of CBF at rest. We tested whether LSCI could allow the study of CBF during a cycling exercise using a specific signal treatment procedure that removes movement-induced artefacts from the LSCI raw signal. We recorded the baseline CBF and peak post-occlusive reactive hyperaemia (PORH) from the cutaneous forearm using LSCI and the mean blood pressure before and during cycling (80 W at 70 rpm) in nine healthy subjects. We determined the cross-correlation coefficient r between LSCI traces obtained before and during cycling and before and after a specifically designed signal processing technique. The results are presented as the median (25th-75th centile) and expressed as the cutaneous vascular conductance (laser speckle perfusion units (LSPU) per millimetre of mercury). Cross-correlation r increased from 0.226 ± 0.140 before to 0.683 ± 0.170 after post-processing. After signal processing, the peak PORH during exercise was reduced [0.38 (0.30-0.52) LSPU/mmHg] compared with the peak PORH during the non-exercise phase [0.69 (0.63-0.74) LSPU/mmHg, p < 0.01], whereas no difference was found between the baseline values. With adequate signal processing, LSCI appears valuable for investigating CBF during exercise. During constant-load lower limb cycling exercise, the upper limb peak PORH is reduced compared with the peak PORH during non-exercise. The underlying mechanisms warrant further investigations in both healthy (trained) subjects and diseased (e.g., coronary heart disease) patients.