Multiparameter assessment of exercise capacity in patients with arterial hypertension

Validity and reliability of the 6-min stepper test in hypertensive individuals

BACKGROUND

Hypertension is a common public health problem characterized by high blood pressure (BP) and associated with complications such as coronary artery disease, stroke, and renal failure. Physical activity and exercise regulate BP, and assessment of exercise capacity is a cornerstone of exercise training.

OBJECTIVE

The aims of this study were to evaluate the validity and reliability of the 6-min stepper test (6MST) in hypertensive individuals and compare their physiological responses during the 6MST and 6-min walk test (6MWT).

METHODS

Forty individuals with hypertension were included. Participants performed the 6MWT and 6MST in separate morning and afternoon sessions. In each session, the test was repeated twice with a 30-min rest interval. Heart rate (HR), BP, perceived dyspnea, general fatigue, and leg fatigue were measured pre and posttest. Intraclass correlation coefficient (ICC), Bland-Altman plots, and standard error of measurement (SEM) were used to assess reliability. Pearson correlation analysis was used for convergent validity.

RESULTS

There was a strong and significant correlation between 6MWT distance and 6MST score ( r  = 0.689, P  < 0.001). Physiological responses during the 6MST had ICC values ranging from 0.70 to 0.89, suggesting good to excellent test-retest reliability. The SEM and minimum detectable difference (MDD) indicated the 6MST had low measurement error and high sensitivity.

CONCLUSION

The 6MST is a valid and reliable tool for assessing exercise capacity in people with HTN. Its practicality and ease of use make it a suitable alternative to the 6MWT for this population.

Cardiopulmonary exercise testing and impedance cardiography in the assessment of exercise capacity of patients with coronary artery disease early after myocardial revascularization

Background

Patients with coronary artery disease (CAD) are characterized by different levels of physical capacity, which depends not only on the anatomical advancement of atherosclerosis, but also on the individual cardiovascular hemodynamic response to exercise. The aim of this study was evaluating the relationship between parameters of exercise capacity assessed via cardiopulmonary exercise testing (CPET) and impedance cardiography (ICG) hemodynamics in patients with CAD.

Methods

Exercise capacity was assessed in 54 patients with CAD (41 men, aged 59.5 ± 8.6 years) within 6 weeks after revascularization by means of oxygen uptake (VO2), assessed via CPET, and hemodynamic parameters [heart rate (HR), stroke volume, cardiac output (CO), left cardiac work index (LCWi)], measured by ICG. Correlations between these parameters at anaerobic threshold (AT) and at the peak of exercise as well as their changes (Δpeak–rest, Δpeak–AT) were evaluated.

Results

A large proportion of patients exhibited reduced exercise capacity, with 63% not reaching 80% of predicted peak VO2. Clinically relevant correlations were noted between the absolute peak values of VO2 versus HR, VO2 versus CO, and VO2 versus LCWi (R = 0.45, p = 0.0005; R = 0.33, p = 0.015; and R = 0.40, p = 0.003, respectively). There was no correlation between AT VO2 and hemodynamic parameters at the AT time point. Furthermore ΔVO2 (peak–AT) correlated with ΔHR (peak–AT), ΔCO (peak–AT) and ΔLCWi (peak–AT) (R = 0.52, p < 0.0001, R = 0.49, p = 0.0001; and R = 0.49, p = 0.0001, respectively). ΔVO2 (peak–rest) correlated with ΔHR (peak–rest), ΔCO (peak–rest), and ΔLCWi (peak–rest) (R = 0.47, p < 0.0001; R = 0.41, p = 0.002; and R = 0.43, p = 0.001, respectively).

Conclusion

ICG is a reliable method of assessing the cardiovascular response to exercise in patients with CAD. Some ICG parameters show definite correlations with parameters of cardiovascular capacity of proven clinical utility, such as peak VO2.

Cardiac function and exercise capacity in patients with metabolic syndrome: A cross-sectional study

Background

Metabolic syndrome is a pre-diabetes condition that is associated with increased cardiovascular morbidity and mortality. We aimed to explore how exercise capacity, cardiac structure, and function were affected in patients with metabolic syndrome.

Methods

Outpatients with echocardiography and exercise stress test combined with impedance cardiography (ETT + ICGG) results available from Nov 2018 to Oct 2020 were retrospectively enrolled. Echocardiographic, ETT + ICG profiles, and exercise performance were compared between patients with metabolic syndrome and the ones without. Sensitivity analyses were performed excluding patients without established coronary heart disease and further 1:1 paired for age and gender, respectively. Multiple linear regression was used to find out related predictors for maximal metabolic equivalents (METs).

Results

Three hundred and twenty-third patients were included, among whom 97 were diagnosed as metabolic syndrome. Compared to patients without metabolic syndrome, echocardiography showed that patients with metabolic syndrome had a significantly lower E/A ratio (p &lt; 0.001). Besides, they have larger left atrium, larger right ventricle, and thicker interventricular septum (all p &lt; 0.001), but similar left ventricular ejection fraction (P = 0.443). ICG showed that patients with metabolic syndrome had significantly higher stroke volume at rest and maximum (p &lt; 0.001), higher left cardiac work index at rest and maximum (p = 0.005), higher systemic vascular resistance (SVR) at rest (p &lt; 0.001), but similar SVI (p = 0.888). During exercise, patients with metabolic syndrome had lower maximal METs (p &lt; 0.001), and a higher proportion suffering from ST-segment depression during exercise (p = 0.009). Sensitivity analyses yielded similar results. As for the linear regression model, 6 independent variables (systolic blood pressure, BMI, E/A ratio, the height of O wave, the peak value of LCWi, and the baseline of SVR) had statistically significant effects on the maximal METs tested in exercise (R = 0.525, R2 = 0.246, P &lt; 0.001).

Conclusion

Patients with metabolic syndrome had significant structural alteration, apparent overburden of left ventricular work index, pre-and afterload, which may be the main cause of impaired exercise tolerance.

RELATIONSHIP BETWEEN THE ECHOCARDIOGRAPHIC RESPONSE OF DIASTOLIC FUNCTION AND LOAD EXERCISE

ABSTRACT Introduction: This article studies the echocardiographic images of patients and observes the changes in diastolic cardiac function after exercise. Objective: This article tries to find the relationship between cardiac images during exercise and the diagnosis of myocardial ischemia. Methods: Samples of people with equal fitness for the same exercise area were selected with specific equipment to measure the sample ventricular strain curve before and after 5 minutes to exercise with a load. The diastolic strain index (SDI) ratio before and after exercise assesses the relationship between myocardial ischemia and exercise load. Results: The test results showed no significant difference in the range of motion of the cardiac atrioventricular annulus both before and after subjects were subjected to intense exertion exercise. A significant change in slope was noted in the ECG data curve about the exercise index, in addition to a reduction in the diastolic period. Conclusion: When the exercise load increases, it can easily cause changes in the ventricular wall. This can make local myocardial dysfunction more prone. Level of evidence II; Therapeutic studies - investigation of treatment results.

Factors Affecting the Exercise Capacity in Pediatric Primary Hypertension

PURPOSE

Exercise training is crucial to the early intervention of pediatric primary hypertension (PHT). However, much less is known about exercise capacity in this disease. This work investigated the exercise capacity in pediatric PHT and analyzed the factors affecting exercise capacity.

METHODS

The study enrolled children with PHT at the Children's Hospital Capital Institute of Pediatrics between July 2017 and July 2020. The Bruce protocol of the treadmill exercise test (TET) was used to assess exercise capacity. Multivariate ordinal logistic regression and generalized linear models were used to analyze factors affecting exercise capacity.

RESULTS

Of 190 patients, 146 (76.8%) were male, and the median age was 13 (11, 14). Most children accomplished TET and achieved the submaximal heart rates (189 [99.5%]). Children with lower resting diastolic blood pressure (DBP) and 24 h average diastolic blood pressure (ADBP) could achieve a TET stage of 6 or more, whereas children with higher DBP and ADBP could only achieve a TET stage of 3 (P all < 0.05). Children with lower DBP and 24 h ADBP were also associated with greater metabolic equivalents (METs; r = -0.237, r = -0.179, P all < 0.05). The completion of TET stages was negatively associated with female (OR = 0.163), younger age (OR = 1.198), greater body mass index (BMI, OR = 0.921), and higher 24 h ADBP (OR = 0.952, P all < 0.05). In addition, METs were negatively associated with female (β = -1.909), younger age (β = 0.282), greater BMI (β = -0.134), and higher 24 h ADBP (β = -0.063, P all < 0.05).

CONCLUSIONS

Exercise capacity was impaired among pediatric PHT patients. Female gender, younger age, greater BMI, and higher 24 h ADBP are independently associated with the exercise capacity in pediatric PHT. These findings may help developing scientific exercise prescriptions for pediatric PHT.

Limited usefulness of resting hemodynamic assessments in predicting exercise capacity in hypertensive patients

Reliable assessments of reduced exercise capacity based on resting tests are one of the major challenges in clinical practice. The aim of this study was to evaluate the relationship between hemodynamic parameters obtained via resting tests (echocardiography and impedance cardiography (ICG)) and objective parameters of exercise capacity assessed via cardiopulmonary exercise testing and exercise ICG in patients with controlled arterial hypertension (AH). The left ventricular ejection fraction (LVEF), global longitudinal strain (GLS), diastolic function parameters (e', E/A, E/e'), cardiac output (CO), stroke volume (SV), and systemic vascular resistance index were evaluated for any correlations with selected parameters of exercise capacity, such as peak oxygen uptake (VO₂) and peak CO in 93 people with AH (mean age 54 years, 47 women). Statistically relevant correlations occurred between indices of exercise capacity (peak VO₂; peak CO) and only the following hemodynamic parameters: diastolic blood pressure (R = 0.23, p = 0.026; R = 0.24, p = 0.021; respectively), e' (R = 0.32, p = 0.002; R = 0.24, p = 0.027), E/e' (R = 0.35, p < 0.001; ns), E/A (R = 0.23, p = 0.030; R = 0.21, p = 0.047), SV at rest (ns; R = 0.24, p = 0.019), and CO at rest (ns; R = 0.21, borderline p = 0.052). No significant correlations between the exercise capacity parameters and either LVEF or GLS were observed. No hemodynamic parameter proved to be an independent correlate of either peak VO₂ or peak CO. The association between hemodynamic parameters at rest and parameters of exercise capacity was weak and limited to selected parameters of diastolic function. Exercise capacity assessment in patients with AH based on resting tests alone is insufficiently reliable and should be supplemented with exercise tests.