scholarly journals Reduced exercise capacity in patients with systemic sclerosis is associated with lower peak tissue oxygen extraction: a cardiovascular magnetic resonance-augmented cardiopulmonary exercise study

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
James T. Brown ◽  
Tushar Kotecha ◽  
Jennifer A. Steeden ◽  
Marianna Fontana ◽  
Christopher P. Denton ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Cardiovascular Magnetic Resonance ◽  
Oxygen Consumption ◽  
Systemic Sclerosis ◽  
Magnetic Resonance ◽  
Oxygen Content ◽  
Oxygen Extraction ◽  
Peak Oxygen Consumption ◽  
Healthy Controls ◽  
Cardiopulmonary Exercise

Abstract Background Exercise intolerance in systemic sclerosis (SSc) is typically attributed to cardiopulmonary limitations. However, problems with skeletal muscle oxygen extraction have not been fully investigated. This study used cardiovascular magnetic resonance (CMR)-augmented cardiopulmonary exercise testing (CMR-CPET) to simultaneously measure oxygen consumption and cardiac output. This allowed calculation of arteriovenous oxygen content gradient, a recognized marker of oxygen extraction. We performed CMR-CPET in 4 groups: systemic sclerosis (SSc); systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH); non-connective tissue disease pulmonary hypertension (NC-PAH); and healthy controls. Methods We performed CMR-CPET in 60 subjects (15 in each group) using a supine ergometer following a ramped exercise protocol until exhaustion. Values for oxygen consumption, cardiac output and oxygen content gradient, as well as ventricular volumes, were obtained at rest and peak-exercise for all subjects. In addition, T1 and T2 maps were acquired at rest, and the most recent clinical measures (hemoglobin, lung function, 6-min walk, cardiac and catheterization) were collected. Results All patient groups had reduced peak oxygen consumption compared to healthy controls (p < 0.022). The SSc and SSc-PAH groups had reduced peak oxygen content gradient compared to healthy controls (p < 0.03). Conversely, the SSc-PAH and NC-PH patients had reduced peak cardiac output compared to healthy controls and SSc patients (p < 0.006). Higher hemoglobin was associated with higher peak oxygen content gradient (p = 0.025) and higher myocardial T1 was associated with lower peak stroke volume (p = 0.011). Conclusions Reduced peak oxygen consumption in SSc patients is predominantly driven by reduced oxygen content gradient and in SSc-PAH patients this was amplified by reduced peak cardiac output. Trial registration The study is registered with ClinicalTrials.gov Protocol Registration and Results System (ClinicalTrials.gov ID: 100358).

Reproducibility of cardiac power output and other cardiopulmonary exercise indices in patients with chronic heart failure

2011 ◽  
Vol 122 (4) ◽  
pp. 175-181 ◽  
Author(s):  
Djordje G. Jakovljevic ◽  
Petar M. Seferovic ◽  
David Nunan ◽  
Gay Donovan ◽  
Michael I. Trenell ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Output ◽  
Oxygen Consumption ◽  
Chronic Heart Failure ◽  
Power Output ◽  
Respiratory Exchange Ratio ◽  
Maximal Exercise ◽  
Peak Oxygen Consumption ◽  
Cardiopulmonary Exercise ◽  
Cardiac Power

Cardiac power output is a direct measure of overall cardiac function that integrates both flow- and pressure-generating capacities of the heart. The present study assessed the reproducibility of cardiac power output and other more commonly reported cardiopulmonary exercise variables in patients with chronic heart failure. Metabolic, ventilatory and non-invasive (inert gas re-breathing) central haemodynamic measurements were undertaken at rest and near-maximal exercise of the modified Bruce protocol in 19 patients with stable chronic heart failure. The same procedure was repeated 7 days later to assess reproducibility. Cardiac power output was calculated as the product of cardiac output and mean arterial pressure. Resting central haemodynamic variables demonstrate low CV (coefficient of variation) (ranging from 3.4% for cardiac output and 5.6% for heart rate). The CV for resting metabolic and ventilatory measurements ranged from 8.2% for respiratory exchange ratio and 14.2% for absolute values of oxygen consumption. The CV of anaerobic threshold, peak oxygen consumption, carbon dioxide production and respiratory exchange ratio ranged from 3.8% (for anaerobic threshold) to 6.4% (for relative peak oxygen consumption), with minute ventilation having a CV of 11.1%. Near-maximal exercise cardiac power output and cardiac output had CVs of 4.1 and 2.2%, respectively. Cardiac power output demonstrates good reproducibility suggesting that there is no need for performing more than one cardiopulmonary exercise test. As a direct measure of cardiac function (dysfunction) and an excellent prognostic marker, it is strongly advised in the assessment of patients with chronic heart failure undergoing cardiopulmonary exercise testing.

scholarly journals Cardiac involvement in COVID-19 patients: mid-term follow up by cardiovascular magnetic resonance

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Hui Wang ◽  
Ruili Li ◽  
Zhen Zhou ◽  
Hong Jiang ◽  
Zixu Yan ◽  
...  
Keyword(s):  
Cardiovascular Magnetic Resonance ◽  
Magnetic Resonance ◽  
Cardiac Involvement ◽  
Global Longitudinal Strain ◽  
Cine Imaging ◽  
Black Blood ◽  
Healthy Controls ◽  
Term Outcome ◽  
Post Contrast

Abstract Background Coronavirus disease 2019 (COVID-19) induces myocardial injury, either direct myocarditis or indirect injury due to systemic inflammatory response. Myocardial involvement has been proved to be one of the primary manifestations of COVID-19 infection, according to laboratory test, autopsy, and cardiovascular magnetic resonance (CMR). However, the middle-term outcome of cardiac involvement after the patients were discharged from the hospital is yet unknown. The present study aimed to evaluate mid-term cardiac sequelae in recovered COVID-19 patients by CMR Methods A total of 47 recovered COVID-19 patients were prospectively recruited and underwent CMR examination. The CMR protocol consisted of black blood fat-suppressed T2 weighted imaging, T2 star mapping, left ventricle (LV) cine imaging, pre- and post-contrast T1 mapping, and late gadolinium enhancement (LGE). LGE were assessed in mixed both recovered COVID-19 patients and healthy controls. The LV and right ventricle (RV) function and LV mass were assessed and compared with healthy controls. Results A total of 44 recovered COVID-19 patients and 31 healthy controls were studied. LGE was found in 13 (30%) of COVID-19 patients. All LGE lesions were located in the mid myocardium and/or sub-epicardium with a scattered distribution. Further analysis showed that LGE-positive patients had significantly decreased LV peak global circumferential strain (GCS), RV peak GCS, RV peak global longitudinal strain (GLS) as compared to non-LGE patients (p < 0.05), while no difference was found between the non-LGE patients and healthy controls. Conclusion Myocardium injury existed in 30% of COVID-19 patients. These patients have depressed LV GCS and peak RV strains at the 3-month follow-up. CMR can monitor the COVID-19-induced myocarditis progression, and CMR strain analysis is a sensitive tool to evaluate the recovery of LV and RV dysfunction.

scholarly journals Association Between 2D- and 3D-Speckle-Tracking Longitudinal Strain and Cardiovascular Magnetic Resonance Evidence of Diffuse Myocardial Fibrosis in Heart Transplant Recipients

2021 ◽  
Vol 8 ◽  
Author(s):  
Wei Sun ◽  
Xuehua Shen ◽  
Jing Wang ◽  
Shuangshuang Zhu ◽  
Yanting Zhang ◽  
...  
Keyword(s):  
Cardiovascular Magnetic Resonance ◽  
Magnetic Resonance ◽  
Myocardial Fibrosis ◽  
Heart Transplant ◽  
Speckle Tracking ◽  
Longitudinal Strain ◽  
Myocardial Strain ◽  
Left Ventricular ◽  
Healthy Controls ◽  
2D And 3D

Objective: This study aimed to: (1) evaluate the association between myocardial fibrosis (MF) quantified by extracellular volume fraction (ECV) and myocardial strain measured by two-dimensional (2D)- and three-dimensional speckle-tracking echocardiography (3D-STE) and (2) further investigate which strain parameter measured by 2D- and 3D-STE is the more robust predictor of MF in heart transplant (HT) recipients.Methods: A total of 40 patients with HT and 20 healthy controls were prospectively enrolled. Left ventricular (LV)-global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) were measured by 2D- and 3D-STE. LV diffuse MF was defined by cardiovascular magnetic resonance (CMR)-ECV.Results: The HT recipients had a significantly higher native T1 and ECV than healthy controls (1043.8 ± 34.0 vs. 999.7 ± 19.7 ms, p &lt; 0.001; 26.6 ± 2.7 vs. 24.3 ± 1.8%, p = 0.02). The 3D- and 2D-STE-LVGLS and LVGCS were lower (p &lt; 0.005) in the HT recipients than in healthy controls. ECV showed a moderate correlation with 2D-LVGLS (r = 0.53, p = 0.002) and 3D-LVGLS (r = 0.60, p &lt; 0.001), but it was not correlated with 2D or 3D-LVGCS, or LVGRS. Furthermore, 3D-LVGLS and 2D-LVGLS had a similar correlation with CMR-ECV (r = 0.60 vs. 0.53, p = 0.670). A separate stepwise multivariate linear analysis showed that both the 2D-LVGLS (β = 0.39, p = 0.019) and 3D-LVGLS (β = 0.54, p &lt; 0.001) were independently associated with CMR-ECV.Conclusion: CMR marker of diffuse MF was present in asymptomatic patients with HT and appeared to be associated with decreased myocardial strain by echocardiography. Both the 2D- and 3D-LVGLS were independently correlated with diffuse LVMF, which may provide an alternative non-invasive tool for monitoring the development of adverse fibrotic remodeling during the follow-up of HT recipients.

Cardiovascular changes in the exercising emu

1983 ◽  
Vol 104 (1) ◽  
pp. 193-201 ◽  
Author(s):  
B. Grubb ◽  
D. D. Jorgensen ◽  
M. Conner
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Oxygen Consumption ◽  
Stroke Volume ◽  
Oxygen Content ◽  
Body Mass ◽  
Fold Increase ◽  
Exercise Heart Rate ◽  
Rate Of Oxygen Consumption ◽  
Cardiovascular Variables

Cardiovascular variables were studied as a function of oxygen consumption in the emu, a large, flightless ratite bird well suited to treadmill exercise. At the highest level of exercise, the birds' rate of oxygen consumption (VO2) was approximately 11.4 times the resting level (4.2 ml kg-1 min-1). Cardiac output was linearly related to VO2, increasing 9.5 ml for each 1 ml increase in oxygen consumption. The increase in cardiac output is similar to that in other birds, but appears to be larger than in mammals. The venous oxygen content dropped during exercise, thus increasing the arteriovenous oxygen content difference. At the highest levels of exercise, heart rate showed a 3.9-fold increase over the resting rate (45.8 beats min-1). The mean resting specific stroke volume was 1.5 ml per kg body mass, which is larger than shown by most mammals. However, birds have larger hearts relative to body mass than do mammals, and stroke volume expressed per gram of heart (0.18 ml g-1) is similar to that for mammals. Stroke volume showed a 1.8-fold increase as a result of exercise in the emus, but a change in heart rate plays a greater role in increasing cardiac output during exercise.

Abstract 17232: Cardiopulmonary Exercise Testing in Diabetic Chronic Heart Failure Patients With Microalbuminuria

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Thida tabucanon ◽  
Timothy Engelman ◽  
Sanjeeb S Bhattacharya ◽  
J Emanuel Finet ◽  
Wai Hong W Tang
Keyword(s):  
Oxygen Consumption ◽  
Exercise Testing ◽  
Beta Blocker ◽  
Multivariable Analysis ◽  
Cardiopulmonary Exercise Testing ◽  
Left Ventricular ◽  
Peak Oxygen Consumption ◽  
Left Ventricular Ejection ◽  
Cardiopulmonary Exercise ◽  
History Of

Introduction: Microalbuminuria can be a presentation of microvascular complication in diabetes mellitus (DM). Hypothesis: Microalbuminuria is associated with impaired exercise performance in chronic HF with DM patients. Methods: We retrospectively analyzed a cardiopulmonary exercise testing (CPET) database in 255 chronic HF patients with DM that had urine microalbumin test between December 2012 and September 2019. Demographic data and CPET parameters were compared between the patients who had and had not microalbuminuria which was defined by microalbumin/creatinine ratio ≥ 30 mg/g. Peak oxygen consumption (peak VO 2 ) ≤ 14 ml/kg/min and ≤ 12 ml/kg/min if had history of beta-blocker uses were classified as low peak VO 2 and used in multivariable analysis. Results: There were a total 92 patients (36.1%) that had microalbuminuria. Mean age was not significant different between the patients with and without microalbuminuria (57.7 vs 59.4 years, p = 0.26). The patients with microalbuminuria had lower body mass index (BMI; 30.8 vs. 32.7 kg/m 2 , p = 0.014) and had more history of beta-blocker (BB) uses (81.5% vs. 69.3%, p = 0.038), no significant different in other medication uses. Left ventricular ejection fraction (LVEF) was significant lower in patients with microalbuminuria (35.8% vs. 41.5%, p = 0.028). The patients with microalbuminuria had significant higher prevalence of low peak VO 2 (45.7% vs. 30.1%, p = 0.015) and lower peak stroke work (VO 2 /HR; 11.5 vs. 12.8 ml/ beat, p = 0.008). No significant different in ventricular efficiency slope (VE/VCO 2 ; 37.1 vs. 35.4, p = 0.094), Multivariable analysis showed that proteinuria was independently associated with low peak VO 2 after adjusted for age, sex, BMI LVEF, history of BB uses, VE/VCO 2 and HR at peak VO 2 , (odds ratio = 3.83, p < 0.001). Conclusions: Microalbuminuria was independently associated with low peak oxygen consumption in chronic HF with DM patients.

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