Priel E; Wahab M; Mondal T; Freitag A; O’Byrne PM; Killian KJ; Satia I;

Current research in physiology [Curr Res Physiol] 2021 Oct 28; Vol. 4, pp. 235-242.
Date of Electronic Publication: 2021 Oct 28 (Print Publication: 2021).

Background: Beta blockers prolong life in patients with cardiovascular diseases. Negative chronotropic and inotropic effects carry the potential to adversely effect peripheral skeletal and airway smooth muscle contributing to further fatigue, dyspnea and exercise intolerance.
Research Questions: Do beta-blockers reduce maximal power output (MPO), VO2 max, cardiorespiratory responses, increase the perceived effort required to cycle and breath during cardiopulmonary exercise tests (CPET) and limit the capacity to exercise?
Methods: Retrospective observational study of subjects performing CPET to capacity from 1988 to 2012. Subjects with and without beta-blockers were compared: baseline physiological characteristics, MPO, VO ₂ max, heart rate max, ventilation responses and perceived exertion required to cycle and breathe (modified Borg scale). Forward stepwise linear additive regression was performed with MPO as the dependent factor with height, age, gender, muscle strength, FEV1 and DLCO as independent contributors.
Results: 42,771 subjects were included 7,787 were receiving beta-blocker [mean age 61 yrs, BMI 28.40 kg/m ² , 9% airflow obstruction (FEV1/FVC<0.7)] and 34,984 were not [mean age 51yrs, BMI 27.40 kg/m ² , 11% airflow obstruction]. Heart rate was lower by 18.2% (95% C.I. 18.15-18.38) (p<0.0001) while Oxygen pulse (VO ₂ /HR) was higher by 19.5% (95% C.I. 19.3-19.7) in those receiving beta blockers. Maximum power output (MPO) was 3.3% lower in those taking beta-blockers. The perceived effort required to cycle and breathe (mBorg) was 8% lower in those taking beta-blockers.
Interpretation: Increases in oxygen pulse minimize the reduction in exercise intolerance and symptom handicap associated with beta-blockers.

Vonbank K; Lehmann A; Bernitzky D; Gysan MR; Simon S; Schrott A;Burtscher M; Idzko M; Gompelmann D;

Frontiers in medicine [Front Med (Lausanne)] 2021 Dec 24; Vol. 8, pp. 773788.
Date of Electronic Publication: 2021 Dec 24 (Print Publication: 2021).

Objectives: Coronavirus disease 2019 (COVID-19) is a global pandemic affecting individuals to varying degrees. There is emerging evidence that even patients with mild symptoms will suffer from prolonged physical impairment. Methods: In this prospective observational study, lung function, and cardiopulmonary exercise testing have been performed in 100 patients for 3-6 months after COVID-19 diagnosis (post-CoVG). Depending on the severity of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection, patients were divided into asymptomatic, or mild to moderate (mild post-CoVG), and severe post-CoVG [hospitalization with or without intensive care unit/non-invasive ventilation (ICU/NIV)]. Results have been compared with age, sex, and body mass index (BMI) matched control group (CG, N = 50).
Results: Both lung function (resting) and exercise capacity (peak workload, Wpeak and peak oxygen uptake, VO ₂ peak – % predicted) were considerably affected in patients with severe post-CoV (81.7 ± 27.6 and 86.1 ± 20.6%), compared to the mild post-CoVG (104.8 ± 24.0%, p = 0.001 and 100.4 ± 24.8; p = 0.003). In addition, also the submaximal exercise performance was significantly reduced in the severe post-CoVG (predicted VT1/VO ₂ peak; p = 0.013 and VT2/VO ₂ peak; p = 0.001). Multiple linear regression analyses revealed that 74 % (adjusted R² ) of the variance in relative VO ₂ peak of patients who had CoV could be explained by the following variables: lower age, male sex, lower BMI, higher DLCO, higher predicted heart rate (HR) peak, lower breathing reserve (BR), and lower SaO ₂ peak, which were related to higher relative VO ₂ peak values. Higher NT-proBNP and lower creatinine kinase (CK) values were seen in severe cases compared to patients who experienced mild CoV.
Discussion: Maximal and submaximal exercise performance in patients recovering from severe COVID-19 remain negatively affected for 3-6 months after COVID-19 diagnosis. The presented findings reveal that impaired pulmonary, cardiac, and skeletal muscle function contributed to the limitation of VO ₂ peak in those patients, which may have important implications on rehabilitation programs.

Burghard M; Takken T; Nap-van der Vlist MM; Nijhof SL; van der Ent CK; Heijerman HGM; Hulzebos HJE;

Therapeutic advances in respiratory disease [Ther Adv Respir Dis] 2022 Jan-Dec; Vol. 16, pp. 17534666211070143.

Objectives: [1] To investigate the cardiorespiratory fitness (CRF) levels in children and adolescents with cystic fibrosis (CF) with no ventilatory limitation (ventilatory reserve ⩾ 15%) during exercise, and [2] to assess which physiological factors are related to CRF.
Methods: A cross-sectional study design was used in 8- to 18-year-old children and adolescents with CF. Cardiopulmonary exercise testing was used to determine peak oxygen uptake normalized to body weight as a measure of CRF. Patients were defined as having ‘low CRF’ when CRF was less than 82%predicted. Physiological predictors used in this study were body mass index z-score, P. Aeruginosa lung infection, impaired glucose tolerance (IGT) including CF-related diabetes, CF-related liver disease, sweat chloride concentration, and self-reported physical activity. Backward likelihood ratio (LR) logistic regression analysis was used.
Results: Sixty children and adolescents (51.7% boys) with a median age of 15.3 years (25th-75th percentile: 12.9-17.0 years) and a mean percentage predicted forced expiratory volume in 1 second of 88.5% (±16.9) participated. Mean percentage predicted CRF (ppVO _2peak/kg ) was 81.4% (±12.4, range: 51%-105%). Thirty-three patients (55.0%) were classified as having ‘low CRF’. The final model that best predicted low CRF included IGT ( p  = 0.085; Exp(B) = 6.770) and P. Aeruginosa lung infection (p = 0.095; Exp(B) = 3.945). This model was able to explain between 26.7% and 35.6% of variance.
Conclusions: CRF is reduced in over half of children and adolescents with CF with normal ventilatory reserve. Glucose intolerance and P. Aeruginosa lung infection seem to be associated to low CRF in children and adolescents with CF.

Seo YG; Kim MK; Sung J; Jeong DS;

Reviews in cardiovascular medicine [Rev Cardiovasc Med] 2021 Dec 22; Vol. 22 (4), pp. 1595-1601.

Evidence of the effect of exercise therapy in patients who have undergone total thoracoscopic ablation is lacking. This study aimed to evaluate the effects of eight weeks exercise-based cardiac rehabilitation on cardiopulmonary fitness and adherence to exercise in patients who underwent total thoracoscopic ablation and followed a regimen of exercise therapy. Twenty-four patients were involved in the study and were divided into two groups. The exercise group underwent exercise therapy, which included aerobic and resistance exercises, twice a week as part of an eight weeks hospital-based outpatient cardiac rehabilitation program. Cardiopulmonary exercise test was used to evaluate exercise capacity and the International Physical Activity Questionnaire was utilized to identify the amount of physical activity and confirm adherence to exercise at six months postoperatively. There were significant differences between the groups in moderate activity level ( p = 0.004) and extent of total physical activity ( p = 0.0001). Complications such as recurrent atrial fibrillation did not occur during the exercise training. Exercise-based cardiac rehabilitation was beneficial in maintaining the activity level at six months postoperatively. Early exercise intervention at four weeks post-surgical ablation is a safe and effective therapy that can increase physical activity. Further studies are needed to verify the effect of exercise intervention in a larger sample size of patients who have undergone total thoracoscopic ablation.

Reuveny R; Luboshitz J; Bar-Dayan A; DiMenna FJ; Jones AM; Segel MJ;

Journal of vascular surgery. Venous and lymphatic disorders [J Vasc Surg Venous Lymphat Disord] 2021 Dec 24.
Date of Electronic Publication: 2021 Dec 24.

Objective: Pulmonary oxygen uptake (V̇O ₂ ) kinetics measured during initiation of exercise mirror energetic transition during daily activity. The aim of this study was to elucidate the pathophysiological mechanisms of exercise limitation of patients with chronic ilio-femoral vein obstruction after deep vein thrombosis by measuring V̇O ₂ kinetics compared to patients with peripheral arterial disease (PAD) and healthy individuals.
Methods: Eleven patients with ilio-femoral vein obstruction (7 man, age 20-65 yrs.), seven patients with PAD (all men, age 44-60 yrs.) and eight healthy participants (5 men, age 28-58 yrs.) were studied. Participants performed upper and lower-limb symptom-limited cardiopulmonary exercise tests on cycle ergometers; and four repeat lower-limb tests at a constant work-rate (WR) corresponding to 90% of the gas exchange threshold for determining V̇O ₂ kinetics.
Results: Phase I V̇O ₂ amplitude in the constant WR tests (% increase over resting V̇O ₂ ), representing the initial surge in cardiac output caused by the emptying of leg veins, was 59±19% in the ilio-femoral vein obstruction group, 73±22% in peripheral arterial disease and 85±26% in healthy participants (p=0.055 for ilio-femoral vein obstruction vs. healthy). Phase II V̇O ₂ kinetics, which largely reflect the kinetics of O ₂ consumption in the exercising muscles, were slower in ilio-femoral vein obstruction (tau = 42±6 s), and PAD (tau = 49±19 s), compared to healthy participants (23±4 s; p<0.01)
CONCLUSIONS: Slow phase II V̇O ₂ kinetics reflect a slow onset of muscular aerobic metabolism in both ilio-femoral vein obstruction and PAD. Low amplitude phase I of V̇O ₂ kinetics observed in ilio-femoral vein obstruction suggests a damped cardio-dynamic phase, consistent with reduced venous return from the obstructed veins. These abnormalities of V̇O ₂ kinetics may contribute to exercise intolerance in ilio-femoral vein obstruction and PAD.

Legris V; Thibault B; Dupuis J; White M; Asgar AW; Fortier A; Pitre C; Bouabdallaoui N; Henri C; O’Meara E; Ducharme A;

ESC heart failure [ESC Heart Fail] 2021 Dec 24. Date of Electronic Publication: 2021 Dec 24.

Aims: Right ventricular (RV) dysfunction, pulmonary hypertension, and exercise intolerance have prognostic values, but their interrelation is not fully understood. We investigated how RV function alone and its coupling with pulmonary circulation (RV-PA) predict cardio-respiratory fitness in patients with heart failure and reduced ejection fraction (HFrEF).
Methods and Results: The Evaluation of Resynchronization Therapy for Heart Failure (EARTH) study included 205 HFrEF patients with narrow (n = 85) and prolonged (n = 120) QRS duration undergoing implantable cardioverter defibrillator implantation. All patients underwent a comprehensive evaluation with exercise tolerance tests and echocardiography. We investigated the correlations at baseline between RV parameters {size, function [tricuspid annular plane systolic excursion (TAPSE), RV fractional area change (RV-FAC), and RV myocardial performance index (RV-MPI)], pulmonary artery systolic pressure (PASP), and tricuspid regurgitation}; left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume index (LVEDVi), and left atrial volume index (LAVi); and cardiopulmonary exercise test (CPET) [peak VO ₂ , minute ventilation/carbon dioxide production (VE/VCO ₂ ), 6 min walk distance (6MWD), and submaximal exercise duration (SED)]. We also studied the relationship between RV-PA coupling (TAPSE/PASP ratio) and echocardiographic parameters in patients with both data available. Univariate and multivariate linear regression models were used. Patients enrolled in EARTH (overall population) were mostly male (73.2%), mean age 61.0 ± 9.8 years, New York Heart Association class II-III (87.8%), mean LVEF of 26.6 ± 7.7%, and reduced peak VO ₂ (15.1 ± 4.6 mL/kg/min). Of these, 100 had both TAPSE and PASP available (TAPSE/PASP population): they exhibited higher BNP, wider QRS duration, larger LVEDVi, with more having tricuspid regurgitation compared with the 105 patients for whom these values were not available (all P < 0.05). RV-FAC (β = 7.5), LAVi (β = -0.1), and sex (female, β = -1.9) predicted peak VO ₂ in the overall population (all P = 0.01). When available, TAPSE/PASP ratio was the only echocardiographic parameter associated with peak VO ₂ (β = 6.8; P < 0.01), a threshold ≤0.45 predicting a peak VO ₂  ≤ 14 mL/kg/min (0.39 for VO ₂  ≤ 12). RV-MPI was the only echocardiographic parameter associated with ventilatory inefficiency (VE/VCO ₂ ) and 6MWD (β = 21.9 and β = -69.3, respectively, both P ≤ 0.01) in the overall population. In presence of TAPSE/PASP, it became an important predictor for those two CPET (β = -18.0 and β = 72.4, respectively, both P < 0.01), together with RV-MPI (β = 18.5, P < 0.01) for VE/VCO ₂ . Tricuspid regurgitation predicted SED (β = -3.2, P = 0.03).
Conclusions: Right ventricular function assessed by echocardiography (RV-MPI and RV-FAC) is closely associated with exercise tolerance in patients with HFrEF. When the TAPSE/PASP ratio is available, this marker of RV-PA coupling becomes the stronger echocardiographic predictor of exercise capacity in this population, highlighting its potential role as a screening tool to identify patients with reduced exercise capacity and potentially triage them to formal peak VO ₂ and/or evaluation for advanced HF therapies.

Stadlbauer A; Philipp A; Blecha S; Lubnow M; Lunz D; Li J; Terrazas A; Schmid C; Lange TJ;Camboni D

Annals of intensive care [Ann Intensive Care] 2021 Dec 24; Vol. 11 (1), pp. 181.
Date of Electronic Publication: 2021 Dec 24.

Background: Since 2019, European guidelines recommend considering extracorporeal life support as salvage strategy for the treatment of acute high-risk pulmonary embolism (PE) with circulatory collapse or cardiac arrest. However, data on long-term survival, quality of life (QoL) and cardiopulmonary function after extracorporeal membrane oxygenation (ECMO) are lacking.
Methods: One hundred and nineteen patients with acute PE and severe cardiogenic shock or in need of mechanical resuscitation (CPR) received venoarterial or venovenous ECMO from 2007 to 2020. Long-term data were obtained from survivors by phone contact and personal interviews. Follow-up included a QoL analysis using the EQ-5D-5L questionnaire, echocardiography, pulmonary function testing and cardiopulmonary exercise testing.
Results: The majority of patients (n = 80, 67%) were placed on ECMO during or after CPR with returned spontaneous circulation. Overall survival to hospital discharge was 45.4% (54/119). Nine patients died during follow-up. At a median follow-up of 54.5 months (25-73; 56 ± 38 months), 34 patients answered the QoL questionnaire. QoL differed largely and was slightly reduced compared to a German reference population (EQ5D5L index 0.7 ± 0.3 vs. 0.9 ± 0.04; p  < 0.01). 25 patients (73.5%) had no mobility limitations, 22 patients (65%) could handle their activities, while anxiety and depression were expressed by 10 patients (29.4%). Return-to-work status was 33.3% (average working hours: 36.2 ± 12.5 h/per week), 15 (45.4%) had retired from work early. 12 patients (35.3%) expressed limited exercise tolerance and dyspnea. 59% (20/34) received echocardiography and pulmonary function testing, 50% (17/34) cardiopulmonary exercise testing. No relevant impairment of right ventricular function and an only slightly reduced mean peak oxygen uptake (76.3% predicted) were noted.
Conclusions: Survivors from severe intractable PE in cardiogenic shock or even under CPR with ECMO seem to recover well with acceptable QoL and only minor cardiopulmonary limitations in the long term. To underline these results, further research with larger study cohorts must be obtained.

Mapelli M; Salvioni E; Paneroni M; Gugliandolo P; Bonomi A; Scalvini S; Raimondo R; Sciomer S; Mattavelli I;
La Rovere MT; Agostoni P;

ESC heart failure [ESC Heart Fail] 2021 Dec 30. Date of Electronic Publication: 2021 Dec 30.

Aims: Cardiopulmonary exercise test (CPET) and 6 min walking test (6MWT) are frequently used in heart failure (HF). CPET is a maximal exercise, whereas 6MWT is a self-selected constant load test usually considered a submaximal, and therefore safer, exercise, but this has not been tested previously. The aim of this study was to compare the cardiorespiratory parameters collected during CPET and 6MWT in a large group of healthy subjects and patients with HF of different severity.
Methods and Results: Subjects performed a standard maximal CPET and a 6MWT wearing a portable device allowing breath-by-breath measurement of cardiorespiratory parameters. HF patients were grouped according to their CPET peak oxygen uptake (peakV̇O ₂ ). One hundred and fifty-five subjects were enrolled, of whom 40 were healthy (59 ± 8 years; male 67%) and 115 were HF patients (69 ± 10 years; male 80%; left ventricular ejection fraction 34.6 ± 12.0%). CPET peakV̇O ₂ was 13.5 ± 3.5 mL/kg/min in HF patients and 28.1 ± 7.4 mL/kg/min in healthy subjects (P < 0.001). 6MWT-V̇O ₂ was 98 ± 20% of the CPET peakV̇O ₂ values in HF patients, while 72 ± 20% in healthy subjects (P < 0.001). 6MWT-V̇O ₂ was >110% of CPET peakV̇O ₂ in 42% of more severe HF patients (peakV̇O ₂  < 12 mL/kg/min). Similar results have been found for ventilation and heart rate. Of note, the slope of the relationship between V̇O ₂ at 6MWT, reported as a percentage of CPET peakV̇O ₂ vs. 6MWT V̇O ₂ reported as the absolute value, progressively increased as exercise limitation did.
Conclusions: In conclusion, the last minute of 6MWT must be perceived as a maximal or even supramaximal exercise activity in patients with more severe HF. Our findings should influence the safety procedures needed for the 6MWT in HF.

Cassady SJ;Glick DR; Williams SR; Lewis GD;

Annals of the American Thoracic Society [Ann Am Thorac Soc] 2022 Jan; Vol. 19 (1), pp. 120-126.

No abstract available

Yazdi D; Sridaran S; Smith S; Centen C; Patel S; Wilson E;Gillon L; Kapur S; Tracy JA; Lewine K; Systrom DM Jr; MacRae CA;

Journal of the American Heart Association [J Am Heart Assoc] 2021 Dec 07, pp. e021893.
Date of Electronic Publication: 2021 Dec 07.

Background Objective markers of cardiac function are limited in the outpatient setting and may be beneficial for monitoring patients with chronic cardiac conditions. We assess the accuracy of a scale, with the ability to capture ballistocardiography, electrocardiography, and impedance plethysmography signals from a patient’s feet while standing on the scale, in measuring stroke volume and cardiac output compared with the gold-standard direct Fick method.
Methods and Results Thirty-two patients with unexplained dyspnea undergoing level 3 invasive cardiopulmonary exercise test at a tertiary medical center were included in the final analysis. We obtained scale and direct Fick measurements of stroke volume and cardiac output before and immediately after invasive cardiopulmonary exercise test. Stroke volume and cardiac output from a cardiac scale and the direct Fick method correlated with r =0.81 and r =0.85, respectively ( P <0.001 each). The mean absolute error of the scale estimated stroke volume was -1.58 mL, with a 95% limits of agreement of -21.97 to 18.81 mL. The mean error for the scale estimated cardiac output was -0.31 L/min, with a 95% limits of agreement of -2.62 to 2.00 L/min. The changes in stroke volume and cardiac output before and after exercise were 78.9% and 96.7% concordant, respectively, between the 2 measuring methods.
Conclusions In a proof-of-concept study, this novel scale with cardiac monitoring abilities may allow for noninvasive, longitudinal measures of cardiac function. Using the widely accepted form factor of a bathroom scale, this method of monitoring can be easily integrated into a patient’s lifestyle.