Effects of carvedilol on oxygen uptake and heart rate kinetics in patients with chronic heart failure at simulated altitude

2011 ◽  
Vol 19 (3) ◽  
pp. 444-451 ◽  
Author(s):  
Marlus Karsten ◽  
Mauro Contini ◽  
Claudia Cefalù ◽  
Gaia Cattadori ◽  
Pietro Palermo ◽  
...  

Background: The response to moderate exercise at altitude in heart failure (HF) is unknown. Methods and results: We evaluated 30 HF patients, (NYHA I-III, 25 M/5 F; 59 ± 10 years; LVEF = 39.6 ± 7.1%), in stable clinical conditions, treated with carvedilol at the maximal tolerated dose. We performed a maximal cardiopulmonary exercise test (CPET) with ramp protocol at sea level to evaluate patients’ performance and two moderate intensity constant workload CPETs (50% of peak workload) at sea level (normoxia) and simulated altitude (hypoxia). Oxygen uptake ([Formula: see text]) and heart rate (HR) on-kinetics at constant workload were assessed calculating the time constant (τ) with a monoexponential equation. [Formula: see text] and HR were higher in hypoxia (0.944 ± 0.233 vs 1.031 ± 0.264 l/min; 100 ± 23 vs 108 ± 22 bpm; p < 0.001). On-kinetics showed a different behavior of τ being [Formula: see text] faster in hypoxia (67.1 ± 23.0 vs. 56.3 ± 19.7 s; p = 0.026) and HR faster in normoxia (49.3 ± 19.4 vs. 62.2 ± 22.5 s; p = 0.018). Ten patients, who lowered oxygen kinetics in hypoxia, had greater HR increase during maximal CPET suggesting lower functional betablockade. The higher τ of [Formula: see text] in hypoxia is likely to be due to a peripheral effect of carvedilol mediated either by β- or α-receptor. Conclusion: HF patients performing moderate exercise at 2000 m simulated altitude have 20% [Formula: see text] increase without trouble at the beginning of exercise when treated with carvedilol.

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Catherine F Notarius ◽  
Daniel A Keir ◽  
Mark B Badrov ◽  
Philip J Millar ◽  
Paul Oh ◽  
...  

Introduction: Elevated muscle sympathetic nerve activity (MSNA) both at rest and during dynamic cycling relates inversely to peak oxygen uptake (VO 2peak ) in patients with heart failure due to a reduced ejection fraction (HFrEF). We observed a drop in MSNA both rest (-6±2 bursts/min) and mild exercise (-4±2) in HFrEF patients after 6 months of cardiac rehabilitation. Hypothesis: We hypothesized that after training those HFrEF patients with LOW VO2peak (less than median 74% of age predicted) would have a larger decrease in MSNA during dynamic exercise than those with HIGH VO2peak (over 74%). Methods: In 21 optimally treated HFrEF patients (5 Female) (13 HIGH: mean VO 2peak =26 ml·kg/min; 98% of predicted; 8 LOW VO 2peak =12; 50%) we assessed VO 2peak (open-circuit spirometry), heart rate variability (HRV) and fibular MSNA (microneurography) at rest, during 1-leg cycling (2 min each of mild and moderate intensity upright 1-leg cycling, n=19) and recovery before and after 6 months of exercise training (45 min aerobic exercise, 5 days/ wk at 60-70 % of VO 2peak; and resistance training 2 days/wk). Results: HIGH and LOW groups had similar age (63±3 vs 63±4 years) , LVEF (30±2 vs 28±3%), BMI, resting heart rate (HR), blood pressure and MSNA (52±3 vs 50±3 bursts/min). Training increased VO 2peak in both groups (main effect P=0.009), with no group difference in HR response or ratings of perceived exertion. MSNA at rest tended to decrease after training in the HIGH but not LOW group (interaction P=0.08). MSNA during cycling increased in both HIGH (P=0.04) and LOW (P<0.001) groups but was blunted post-training in the HIGH group only (P=0.04 vs. 0.90 in LOW). Training-induced sympatho-inhibition during exercise recovery occurred in the HIGH but not LOW group (interaction P=0.01). In contrast, HRV was not improved by training in either group. Conclusions: Contrary to our hypothesis, the sympatho-inhibitory effect of 6 months of exercise-based cardiac rehabilitation favours HFrEF patients with an already normal VO 2peak . This suggests that increasing initially low VO 2peak may be insufficient to trigger beneficial exercise and recovery autonomic modulation and altered training paradigms may be required in such patients. Funded by Canadian Institutes for Health Research (CIHR)


2020 ◽  
Vol 27 (2_suppl) ◽  
pp. 59-64
Author(s):  
Damiano Magrì ◽  
Giovanna Gallo ◽  
Gianfranco Parati ◽  
Mariantonietta Cicoira ◽  
Michele Senni

Heart failure with mid-range ejection fraction represents a heterogeneous and relatively young heart failure category accounting for nearly 20–30% of the overall heart failure population. Due to its complex phenotype, a reliable clinical picture of heart failure with mid-range ejection fraction patients as well as a definite risk stratification are still relevant unsolved issues. In such a context, there is growing interest in a comprehensive functional assessment by means of a cardiopulmonary exercise test, yet considered a cornerstone in the clinical management of patients with heart failure and reduced ejection fraction. Indeed, the cardiopulmonary exercise test has also been found to be particularly useful in the heart failure with mid-range ejection fraction category, several cardiopulmonary exercise test-derived parameters being associated with a poor outcome. In particular, a recent contribution by the metabolic exercise combined with cardiac and kidney indexes research group showed an independent association between the peak oxygen uptake and pure cardiovascular mortality in a large cohort of recovered heart failure with mid-range ejection fraction patients. Contextually, the same study supplied an easy approach to identify a high-risk heart failure with mid-range ejection fraction subset by using a combination of peak oxygen uptake and ventilatory efficiency cut-off values, namely 55% of the maximum predicted and 31, respectively. Thus, looking at the above-mentioned promising results and waiting for specific trials, it is reasonable to consider cardiopulmonary exercise test assessment as part of the heart failure with mid-range ejection fraction work-up in order to identify those patients with an unfavourable functional profile who probably deserve a close clinical follow-up and, probably, more aggressive therapeutic strategies.


2019 ◽  
Vol 6 (10) ◽  
pp. 190639
Author(s):  
Lucas Raphael Bento Silva ◽  
Paulo Roberto Viana Gentil ◽  
Thomas Beltrame ◽  
Marco Antônio Basso Filho ◽  
Fagner Medeiros Alves ◽  
...  

The aim of this study was to compare the heart rate (HR) dynamics and variability before and after high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) protocols with workloads based on treadmill workload at which maximal oxygen uptake was achieved ( WL V ˙ O 2 max ) . Ten participants performed cardiopulmonary exercise testing (CPET) to obtain oxygen uptake ( WL V ˙ O 2 max ) . All training protocols were performed on a treadmill, with 0% grade, and had similar total distance. The MICT was composed by 21 min at 70% of WL V ˙ O 2 max . The first HIIT protocol (HIIT-30 : 30) was composed by 29 repetitions of 30 s at 100% of s V ˙ O 2 max and the second HIIT protocol (HIIT-4 : 3) was composed by three repetitions of 4 min at 90% of WL V ˙ O 2 max . Before, during and after each training protocol, HR dynamics and variability (HRV) were analysed by standard kinetics and linear (time and frequency domains). The repeated measures analysis of variance indicated that the HR dynamics, which characterizes the speed of HR during the rest to exercise transition, was statistically ( p < 0.05) slower during MICT in comparison to both HIIT protocols. The HRV analysis, which characterizes the cardiac autonomic modulation during the exercise recovery, was statistically higher in HIIT-4 : 3 in comparison to MICT and HIIT-30 : 30 protocols ( p < 0.005 and p = 0.012, respectively), suggesting that the HIIT-4 : 3 induced higher sympathetic and lower parasympathetic modulation during exercise in comparison to the other training protocols. In conclusion, HIIT-4 : 3 demonstrated post-exercise sympathetic hyperactivity and a higher HRpeak, while the HIIT-30 : 30 and MICT resulted in better HRV and HR in the exercise-recovery transition. The cardiac autonomic balance increased in HIIT-30 : 30 while HIIT-4 : 3 induced sympathetic hyperactivity and cardiac overload.


2019 ◽  
Vol 29 (12) ◽  
pp. 1445-1451
Author(s):  
António V. Gonçalves ◽  
Tânia Mano ◽  
Ana Agapito ◽  
Sílvia A. Rosa ◽  
Lídia de Sousa ◽  
...  

AbstractIntroduction:Both transposition of the great arteries (TGA) previously submitted to a Senning/Mustard procedure and congenitally corrected TGA (cc-TGA) have the systemic circulation supported by the morphological right ventricle, thereby rendering these patients to heart failure events risk. The aim of this study was to evaluate cardiopulmonary exercise test parameters for stratifying the risk of heart failure events in TGA patients.Methods:Retrospective evaluation of adult TGA patients with systemic circulation supported by the morphological right ventricle submitted to cardiopulmonary exercise test in a tertiary centre. Patients were followed up for at least 1 year for the primary endpoint of cardiac death or heart failure hospitalisation. Several cardiopulmonary exercise test parameters were analysed as potential predictors of the combined endpoint and their predictive power were compared (area under the curve).Results:Cardiopulmonary exercise test was performed in 44 TGA patients (8 cc-TGA), with a mean age of 35.1 ± 8.4 years. The primary endpoint was reached by 10 (22.7%) patients, with a mean follow-up of 36.7 ± 26.8 months. Heart rate at anaerobic threshold had the highest area under the curve value (0.864), followed by peak oxygen consumption (pVO2) (0.838). Heart rate at anaerobic threshold ≤95 bpm and pVO2 ≤20 ml/kg/min had a sensitivity of 87.5 and 80.0% and a specificity of 82.4 and 76.5%, respectively, for the primary outcome.Conclusion:Heart rate at anaerobic threshold ≤95 bpm had the highest predictive power of all cardiopulmonary exercise test parameters analysed for heart failure events in TGA patients with systemic circulation supported by the morphological right ventricle.


2022 ◽  
Vol 12 ◽  
Author(s):  
Mara Paneroni ◽  
Simonetta Scalvini ◽  
Ugo Corrà ◽  
Marta Lovagnini ◽  
Roberto Maestri ◽  
...  

Background: In elderly chronic heart failure (HF) patients, activities of daily living (ADLs) require the use of a high proportion of patients’ peak aerobic capacity, heart rate, and ventilation.Objectives: To assess the effects of short-term comprehensive cardiac rehabilitation (CR) on the metabolic requirement of ADLs in elderly patients with chronic HF.Methods: The study population comprised 99 elderly chronic HF patients (mean age 72 ± 5 years, 80% male, 61% ejection fraction &lt;40%, mean NT-proBNP 2,559 ± 4,511 pg/ml) participating in a short-term (mean days 19 ± 7) residential CR program. Before and after CR, participants, while wearing a portable ergospirometer, performed a standardized ADL battery: ADL1 (getting dressed), ADL2 (folding 8 towels), ADL3 (putting away 6 bottles), ADL4 (making a bed), ADL5 (sweeping the floor for 4 min), ADL6 (climbing 1 flight of stairs carrying a 1.5 Kg load), and ADL7 (a standard 6-min walking test).Results: After CR, task-related oxygen uptake did not change in any of the domestic ADLs. Notably, there was a significant decrease in the cumulative time required to perform ADLs (ADL 1–4 and ADL6; from 412 ± 147 to 388 ± 141 s, p = 0.001) and a reduction in maximal heart rate in ADL1 and 3 (p = 0.005 and p = 0.027, respectively). Changes occurred in the 6MWT with an increase in oxygen uptake (p = 0.005) and in the distance covered (p &lt; 0.001) and a significant decrease in the Borg scale of dyspnea (p = 0.004).Conclusion: Elderly patients with chronic heart failure who are engaged in a short-term residential CR program improve the performance of routine ADLs.


2013 ◽  
Vol 38 (2) ◽  
pp. 154-160 ◽  
Author(s):  
Shilpa Dogra ◽  
Matthew D. Spencer ◽  
Juan M. Murias ◽  
Donald H. Paterson

The rate of adjustment for pulmonary oxygen uptake (τV̇O2p) is slower in untrained and in older adults. Near-infrared spectroscopy (NIRS) has shed light on potential mechanisms underlying this in young men and women and in older men; however, there is no such data available in older women. The purpose of this study was to gain a better understanding of the mechanisms of slower τV̇O2p in older women who were either endurance-trained or untrained. Endurance-trained (n = 10; age, 62.6 ± 1.0 years) and untrained (n = 9; age, 69.1 ± 2.2 years) older women attended 2 maximal and 2 submaximal (90% of ventilatory threshold) exercise sessions. Oxygen uptake (V̇O2) was measured breath by breath, using a mass spectrometer, and changes in deoxygenated hemoglobin concentration of the vastus lateralis ([HHb]) were measured using NIRS. Heart rate was measured continuously with a 3-lead electrocardiogram. τV̇O2p was faster in trained (35.1 ± 5.5 s) than in untrained (57.0 ± 8.1 s) women. The normalized [HHb] to V̇O2 ratio, an indicator of muscle O2 delivery to O2 utilization, indicated a smaller overshoot in trained (1.09 ± 0.1) than in untrained (1.39 ± 0.1) women. Heart rate data indicated a faster adjustment of heart rate in trained (33.0 ± 13.0) than in untrained (68.7 ± 14.1) women. The pairing of V̇O2p data with NIRS-derived [HHb] data indicates that endurance-trained older women likely have better matching of O2 delivery to O2 utilization than older untrained women during moderate-intensity exercise, leading to a more rapid adjustment of V̇O2p.


2013 ◽  
Vol 8 (3) ◽  
pp. 319-322 ◽  
Author(s):  
Dionne A. Noordhof ◽  
Thijs Schoots ◽  
Derk H. Hoekert ◽  
Jos J. de Koning

Purpose:The purpose of this study was to test the assumption that gross efficiency (GE) at sea level (SL) is representative of GE at altitude (AL). It was hypothesized that an increased cost of ventilation and heart rate, combined with a higher respiratory-exchange ratio, at AL might result in a decrease in GE.Methods:Trained men (N = 16) completed 2 maximal incremental tests and 2 GE tests, 1 at SL and 1 at an acute simulated AL of 1500 m (hypobaric chamber). GE was determined during submaximal exercise at 45%, 55%, and 65% of the altitude-specific power output attained at VO2max.Results:GE determined at the highest submaximal exercise intensity with a mean RER ≤1.0, matched for both conditions, was significantly lower at AL (AL 20.7% ± 1.1% and SL 21.4% ± 0.8%, t15 = 2.9, P < .05).Conclusion:These results demonstrate that moderate AL resulted in a significantly lower GE during cycling exercise than SL. However, it might be that the lower GE at AL is caused by the lower absolute exercise intensity.


2019 ◽  
Vol 19 (37) ◽  
pp. 137-141
Author(s):  
Holly Bogdanich ◽  
Jan Kiger ◽  
Julia Matzenbacher Santos

Sauna baths acutely increases vasodilation, heart rate (HR) and muscle relaxation; therefore sessions of sauna have been tested as a therapeutic treatment for cardiovascular diseases and psychological diseases. When combined with exercise, sauna baths have been performed to accelerate exercise recovery, with the sauna being done post workout the majority of times. The aim of this study was to determine the effects of the sauna used prior to a bout of moderate intensity aerobic exercise. Eight volunteer performed a 20-minute treadmill aerobic exercise (running) 70% of maximal VO2 with and without a visit to the sauna. Systolic and diastolic blood pressure (BP), HR, and Rate of Perceived Exertion (RPE) were recorded before, halfway at 10 minutes, and after the aerobic exercise. Systolic BP, assessed before exercise, was not different when subjects performed prior sauna (124.8 ± 10.8 vs. 125± 11 mm/Hg no sauna and sauna, respectively). However, diastolic BP was lower in no-sauna condition vs. sauna condition while HR and RPE (73± 5 vs 80± 4.5 mm/Hg BP, 90±13 vs. 101±11 beats/min and 6 vs. 7 RPE no sauna and sauna, respectively). When the comparison was made within the experimental condition exercise, sauna attenuated the increase in systolic and diastolic BP induced by exercise without affecting HR and RPE. Extreme high temperatures experienced in sauna modulate cardiovascular system responses by increasing HR and diastolic blood pressure. Moderate exercise increases systolic and diastolic BP, which might be attenuated when sauna is performed prior to exercise. A Sauna session might be used to modulate the response of exercise towards BP.


2020 ◽  
Vol 13 (11) ◽  
Author(s):  
Massimo Mapelli ◽  
Elisabetta Salvioni ◽  
Alice Bonomi ◽  
Paola Gugliandolo ◽  
Fabiana De Martino ◽  
...  

Background: Cardiopulmonary exercise test and 6-minute walking test are frequently used tools to evaluate physical performance in heart failure (HF), but they do neither represent activities of daily living (ADLs) nor fully reproduce patients’ symptoms. We assessed differences in task oxygen uptake, both as absolute value and as percentage of peak oxygen consumption (peakVO 2 ), ventilation efficiency (VE/VCO 2 ratio), and dyspnea intensity (Borg scale) in HF and healthy subjects during standard ADLs and other common physical actions. Methods: Healthy and HF subjects (ejection fraction <45%, stable conditions) underwent cardiopulmonary exercise test. All of them, carrying a wearable metabolic cart, performed a 6-minute walking test, two 4-minute treadmill exercises (at 2 and 3 km/h), and ADLs: ADL1 (getting dressed), ADL2 (folding 8 towels), ADL3 (putting away 6 bottles), ADL4 (making a bed), ADL5 (sweeping the floor for 4 minutes), ADL6 (climbing 1 flight of stairs carrying a load). Results: Sixty patients with HF (age 65.2±12.1 years; ejection fraction 30.4±6.7%, peakVO 2 14.2±4.0 mL/[min·kg]) and 40 healthy volunteers (58.9±8.2 years, peakVO 2 28.1±7.4 mL/[min·kg]) were enrolled. For each exercise, patients showed higher VE/VCO 2 ratio, percentage of peakVO 2 , and Borg scale value than controls, while absolute values of task oxygen uptake and exercise duration were lower and higher, respectively, in all activities, except for treadmill (fixed execution time and intensity). Differently from Borg Scale data, metabolic values and exercise time length changed in parallel with HF severity, except for ADL duration in very short (ADL3) and composite (ADL1) activities. Borg scale values correlated with percentage of peakVO 2 . Conclusions: During ADLs, patients self-regulated activities in parallel with HF severity by decreasing intensity (VO 2 ) and prolonging the effort.


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