A verification phase adds little value to the determination of maximum oxygen uptake in well-trained adults.

PURPOSE: The objective was to investigate if performing a sub-peak or supra-peak verification phase following a ramp test provides additional value for determining 'true' maximum oxygen uptake ( V ˙ O2). METHODS: 17 and 14 well-trained males and females, respectively, performed two ramp tests each followed by a verification phase. While the ramp tests were identical, the verification phase differed in power output, wherein the power output was either 95% or 105% of the peak power output from the ramp test. The recovery phase before the verification phase lasted until capillary blood lactate concentration was ≤ 4 mmol·L-1. If a V ˙ O2 plateau occurred during ramp test, the following verification phase was considered to provide no added value. If no V ˙ O2 plateau occurred and the highest V ˙ O2 ( V ˙ O2peak) during verification phase was < 97%, between 97 and 103%, or > 103% of V ˙ O2peak achieved during the ramp test, no value, potential value, and certain value were attributed to the verification phase, respectively. RESULTS: Mean (standard deviation) V ˙ O2peak during both ramp tests was 64.5 (6.0) mL·kg-1·min-1 for males and 54.8 (6.2) mL·kg-1·min-1 for females. For the 95% verification phase, 20 tests showed either a V ˙ O2 plateau during ramp test or a verification V ˙ O2peak < 97%, indicating no value, 11 showed potential value, and 0 certain value. For the 105% verification phase, the values were 26, 5, and 0 tests, respectively. CONCLUSION: In well-trained adults, a sub-peak verification phase might add little value in determining 'true' maximum V ˙ O2, while a supra-peak verification phase adds no value.

Changes in Exercise Tolerance over Time in Patients with Transthyretin Amyloidosis Cardiomyopathy Treated with Tafamidis.

Tafamidis improves the prognosis of patients with transthyretin amyloidosis cardiomyopathy (ATTR-CM). Additionally, it delays the decline in exercise tolerance, as observed in the six-minute walking test. However, the changes in cardiopulmonary function over time based on cardiopulmonary exercise tests are unclear. Thus, this preliminary study investigated the changes in exercise tolerance after one year of tafamidis treatment using cardiopulmonary exercise testing. Eight patients with ATTR-CM (average age: 77 years; male: n = 7) underwent cardiopulmonary exercise testing at baseline and after one year of tafamidis treatment. All eight patients completed a one-year follow-up. At baseline, the anaerobic threshold oxygen uptake (AT VO2: 10.9 ± 1.5) and peak VO2 (14.3 ± 3.0 mL/kg/minute) indicated relatively favorable exercise capacity; however, the minute ventilation/carbon dioxide production (VE/VCO2 slope), which indicates effective ventilation, showed poor performance (33.7 ± 12.8). One year after tafamidis treatment, frailty, as assessed by the Clinical Frailty Scale, had progressed in seven of eight patients (88%) (P < 0.01), and AT VO2 and peak VO2 were significantly reduced (19.2% and 22.3%, respectively; P < 0.05). The VE/VCO2 slope and peak O2 pulse decreased nonsignificantly by approximately 20% (P = 0.47, and P = 0.16, respectively). Further, the structure of the ventricles and atrium and the left ventricle ejection fraction on echocardiography did not change. Thus, exercise tolerance in patients with ATTR-CM was reduced after one year despite tafamidis administration. Not only ATTR-CM progression, but also frailty progression may influence this decrease in exercise tolerance. A comprehensive approach, including tafamidis administration and cardiac rehabilitation, is required for further improvement in the exercise capacity of patients with ATTR-CM.

Impact of the COVID-19 pandemic on exercise tolerance and patient outcomes with Phase III cardiac rehabilitation in Japan: A multicenter study.

This study aimed to determine how behavioural restrictions due to the emergency declaration following the coronavirus disease 2019 (COVID-19) pandemic affect exercise tolerance and its outcomes in patients in Phase III cardiac rehabilitation programme. This is a multicenter retrospective cohort study. Participants in outpatient cardiac rehabilitation programmes and cardiopulmonary exercise testing before and after the emergency declarations were included. A total of 90 participants were included (median age 75.0 years, 69% male), and the changes in physical function and exercise tolerance were compared before and after the emergency declaration. Patients were divided into a decline-in-peak oxygen uptake (VO2 ) group and a nondecline-in-peak VO2 group. Comparison before and after the emergency declaration showed that the anaerobic threshold declined significantly and peak VO2 exhibited a downward trend. The decline-in-peak VO2 group consisted of 16 patients (17%) with better exercise tolerance, multiple comorbidities, and declined lower extremity muscle strength. These patients also had a higher rate of subsequent composite events (hazard ratio, 5.2; 95% confidence interval, 1.4-18.8, p = 0.01). Before and after the emergency declaration, the patient's exercise tolerance may decline, leading to a poor prognosis. This study suggests the importance of maintaining exercise tolerance during the COVID-19 pandemic.

Enhanced external counterpulsation ameliorates endothelial dysfunction and elevates exercise tolerance in patients with coronary artery disease.

Purpose: Enhanced external counterpulsation (EECP) is a new non-drug treatment for coronary artery disease (CAD). However, the long-term effect of EECP on endothelial dysfunction and exercise tolerance, and the relationship between the changes in the endothelial dysfunction and exercise tolerance in the patients with coronary heart disease are still unclear. Methods: A total of 240 patients with CAD were randomly divided into EECP group (n = 120) and control group (n = 120). All patients received routine treatment of CAD as the basic therapy. Patients in the EECP group received 35 1-h daily sessions of EECP during 7 consecutive weeks while the control group received the same treatment course, but the cuff inflation pressure was 0-10 mmHg. Peak systolic velocity (PSV), end diastolic velocity (EDV), resistance index (RI), and inner diameter (ID) of the right carotid artery were examined using a Color Doppler Ultrasound and used to calculate the fluid shear stress (FSS). Serum levels of human vascular endothelial cell growth factor (VEGF), vascular endothelial cell growth factor receptor 2 (VEGFR2), and human angiotensin 2 (Ang2) were determined by enzyme-linked immunosorbent assay (ELISA). Exercise load time, maximal oxygen uptake (VO2max ), metabolic equivalent (METs), anaerobic threshold (AT), peak oxygen pulse (VO2max/HR) were assessed using cardiopulmonary exercise tests. Results: After 1 year follow-up, the EDV, PSV, ID, and FSS were significantly increased in the EECP group (P < 0.05 and 0.01, respectively), whereas there were no significant changes in these parameters in the control group. The serum levels of VEGF and VEGFR2 were elevated in the EECP and control groups (all P < 0.05). However, the changes in VEGF and VEGFR2 were significantly higher in the EECP group than in the control group (P < 0.01). The serum level of Ang2 was decreased in the EECP group (P < 0.05) and no obvious changes in the control group. As for exercise tolerance of patients, there were significant increases in the exercise load time, VO2max, VO2max/HR, AT and METs in the EECP group (all P < 0.05) and VO2max and METs in the control group (all P < 0.05). Correlation analyses showed a significant and positive correlations of VEGF and VEGFR2 levels with the changes in FSS (all P < 0.001). The correlations were still remained even after adjustment for confounders (all Padjustment < 0.001). Linear regression displays the age, the medication of ACEI (angiotensin-converting enzyme inhibitors) or ARB (angiotensin receptor blockers), the diabetes and the changes in VEGF and VEGFR2 were positively and independently associated with the changes in METs after adjustment for confounders (all Padjustment < 0.05). Conclusion: The data of our study suggested that EECP is a useful therapeutic measurement for amelioration of endothelial dysfunction and long-term elevation of exercise tolerance for patients with coronary heart disease. Clinical trial registration: [http://www.chictr.org.cn/], identifier [ChiCTR1800020102].

Heart Failure with Reduced Ejection Fraction and Prognostic Scales: The Impact of Exercise Modality in Cardiopulmonary Exercise Tests.

The cardiopulmonary exercise (CPET) test is an essential tool to determine the severity, prognosis, and need for invasive treatments in heart failure with reduced ejection fraction (HFrEF) but disregards the exercise modality. The present study aimed at analyzing the differences between treadmill and cycle-ergometer exercises. This was a prospective study, involving 65 patients with HfrEF who performed treadmill exercise followed by cycle-ergometer exercise 72 h later. We enrolled 65 patients, aged 58 ± 9 years, with an ejection fraction of 29 ± 9%. Peak VO2 was 20% greater (95% CI: 18−21%; p < 0.000) on the treadmill, and the ventilatory efficiency estimated by the VE/VCO2 slope (32 ± 8 vs. 34 ± 9; p < 0.05). The ventilatory response was greater on the treadmill: maximum ventilation (55 ± 16 vs. 46 ± 11 L/min; p < 0.000) and ventilatory reserve at the maximum effort (28 ± 17 vs. 41 ± 15%; p < 0.000). These values led to a change in the functional class of 23 (51%) patients and ventilatory class of 28 (47%) patients. Differences in the main parameters, including peak VO2 and VE/VCO2, impact prognostic scales and possible advanced treatments; therefore, the results should be interpreted in accordance with the exercise modality.

Ventilatory limitations are not associated with dyspnea on exertion or reduced aerobic fitness in pectus excavatum.

Exercise intolerance and chest pain are common symptoms in patients with pectus excavatum. To assess if the anatomic extent of pectus deformities determined by the correction index (CI) is associated with a pulmonary impairment at rest and during exercise we performed a retrospective review on pectus patients in our center who completed a symptom questionnaire, cardiopulmonary exercise test (CPET), pulmonary function tests (PFT), and chest magnetic resonance imaging. Of 259 patients studied, dyspnea on exertion and chest pain was reported in 64% and 41%, respectively. Peak oxygen uptake (VO2 ) was reduced in 30% and classified as mild in two-thirds. A pulmonary limitation during exercise was identified in less than 3%. Ventilatory limitations on PFT was found in 26% and classified as mild in 85%. Obstruction was the most common abnormal pattern (11%). There were no differences between patients with normal or abnormal PFT patterns for the CI, VO2, or percentage reporting dyspnea or chest pain. Scatter plots demonstrated significant but weak inverse relationships between the CI and lung volumes at rest and during exercise. Multivariable linear regression modeling evaluating predictors of VO2 demonstrated positive associations with the forced expiratory volume at one second and a negative association with the CI. We conclude that resting PFT patterns have poor correlation with the anatomic extent of the pectus defect, symptomatology or aerobic fitness. Pulmonary limitations on CPET are uncommon and lung volumes during exercise are only minimally associated with the CI.

Resting respiratory lung volumes are "healthier" than exercise respiratory volumes in different types of palliated or corrected congenital heart disease.

AIMS: Cardiac surgery has improved life expectancy of patients with congenital heart diseases (CHDs). Exercise capacity is an important determinant of survival in patients with CHDs. There is a lack of studies focusing on the role of resting respiratory performance in reducing exercise tolerance in these patients. OBJECTIVES: To determine the prevalence and severity of respiratory functional impairment in different types of corrected/palliated CHDs, and its impact on an exercise test. MATERIALS AND METHODS: Retrospective single-center study involving 168 corrected/palliated patients with CHD and 52 controls. Patients CHD were divided into subgroups according to the presence of native pulmonary blood flow or total cavopulmonary connection (TCPC). All subjects performed complete pulmonary function tests and gas diffusion; patients with CHD also performed cardiopulmonary exercise test (CPX). RESULTS: Mean values of lung volumes were within the normal range in all CHD groups. Comparing to controls, patients with the reduced pulmonary flow and with TCPC had the highest reduction in lung volumes. CPX was reduced in all groups, most severely in TCPC, and it was correlated to decreased dynamic volumes in all CHD groups except in TCPC. Younger age at intervention and number of surgical operations negatively affected lung volumes. CONCLUSIONS: Respiratory function is within the normal range in our patients with different CHDs at rest but altered in all CHDs during exercise when cardiorespiratory balance is likely to be inadequate. Comparing the different groups, patients with reduced pulmonary flow and TCPC are the most impaired.

Changes in Strain Pattern and Exercise Capacity after Transcatheter Closure of Atrial Septal Defects.

BACKGROUND AND OBJECTIVES: Assessment of left ventricle (LV) function by using strain and strain rate is popular in the clinical setting. However, the use of these echocardiographic tools in assessing right ventricle (RV) failure, and the manner in which they both reflect the functional capacity of the patient, remains poorly understood. This study aimed to investigate the change in exercise capacity and strain between before and (1 month) after the transcatheter closure of atrial septal defects (ASDs). SUBJECTS AND METHODS: Thirty patients who underwent transcatheter closure of ASD between May 2014 and June 2015 at the Division of Pediatric Cardiology, Severance Cardiovascular Hospital, were enrolled. We compared and analyzed the results of the following examinations, before and (1 month) after the procedure: echocardiography, cardiopulmonary exercise test (CPET), and N-terminal pro-brain natriuretic peptide level. RESULTS: There were no mortalities, and the male-to-female ratio was 1:2. The mean defect size was 22.3±4.9 mm; the mean Qp/Qs ratio, 2.1±0.5; and the mean device size, 22.3±4.9 mm. Changes in global RV longitudinal (GRVL) strain and LV torsion were measured echocardiographically. Exercise capacity improved from 7.7±1.2 to 8.7±1.8 metabolic equivalents (p=0.001). These findings correlated to the change in GRVL strain (p=0.03). CONCLUSION: The average exercise capacity increased after device closure of ASD. The change in strain was evident on echocardiography, especially for GRVL strain and LV torsion. Further studies comparing CPET and strain in various patients may show increased exercise capacity in patients with improved RV function.

Changes in Strain Pattern and Exercise Capacity after Transcatheter Closure of Atrial Septal Defects

BACKGROUND AND OBJECTIVES: Assessment of left ventricle (LV) function by using strain and strain rate is popular in the clinical setting. However, the use of these echocardiographic tools in assessing right ventricle (RV) failure, and the manner in which they both reflect the functional capacity of the patient, remains poorly understood. This study aimed to investigate the change in exercise capacity and strain between before and (1 month) after the transcatheter closure of atrial septal defects (ASDs). SUBJECTS AND METHODS: Thirty patients who underwent transcatheter closure of ASD between May 2014 and June 2015 at the Division of Pediatric Cardiology, Severance Cardiovascular Hospital, were enrolled. We compared and analyzed the results of the following examinations, before and (1 month) after the procedure: echocardiography, cardiopulmonary exercise test (CPET), and N-terminal pro-brain natriuretic peptide level. RESULTS: There were no mortalities, and the male-to-female ratio was 1:2. The mean defect size was 22.3±4.9 mm; the mean Qp/Qs ratio, 2.1±0.5; and the mean device size, 22.3±4.9 mm. Changes in global RV longitudinal (GRVL) strain and LV torsion were measured echocardiographically. Exercise capacity improved from 7.7±1.2 to 8.7±1.8 metabolic equivalents (p=0.001). These findings correlated to the change in GRVL strain (p=0.03). CONCLUSION: The average exercise capacity increased after device closure of ASD. The change in strain was evident on echocardiography, especially for GRVL strain and LV torsion. Further studies comparing CPET and strain in various patients may show increased exercise capacity in patients with improved RV function.

Effects of diaphragm plication on pulmonary function and cardiopulmonary exercise parameters.

OBJECTIVES: Paralysis of the diaphragm is an uncommon condition, which may result in dyspnoea on excertion and in orthopnea. In patients who have symptoms, the paralysed diaphragm is often plicated to prevent its paradoxical movement on inspiration. This procedure brings relief to many patients, but the mechanism for this improvement is not well understood. METHODS: Nine symptomatic patients who underwent plication of a unilateral paralysed hemidiaphragm were prospectively evaluated. All patients underwent pulmonary function tests and cardiopulmonary exercise tests before surgery and repeated them after surgery. RESULTS: Patients with hemidiaphragm paralysis before surgery were found to have lower tidal volumes at any given ventilation rate during exercise than normal subjects. A clear and consistent change was found in the manner in which patients increased their ventilation during exercise after surgery. All patients showed an increase in tidal volume for a given ventilation rate, which was significant. The plication procedure reduced the respiratory rate for any exercise level in all patients, and this effect was more pronounced during exercise. CONCLUSIONS: In patients with hemidiaphragm paralysis who underwent a diaphragm plication exercise, tidal volumes increased and the ventilatory frequency decreased. Despite this improvement, maximal exercise capacity remained unaltered.