55 Brisk walking can be a maximal effort in heart failure patients. A comparison of cardiopulmonary exercise and 6-min walking test cardiorespiratory data

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 (peakṼO2). 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 peakṼO2 was 13.5 ± 3.5 ml/kg/min in HF patients and 28.1 ± 7.4 ml/kg/min in healthy (P < 0.001). 6MWT-ṼO2 was 98 ± 20% of the CPET peakṼO2 values in HF patients, while 72 ± 20% in healthy subjects (P < 0.001). 6MWT-ṼO2 was >110% of CPET peakṼO2 in 42% of more severe HF patients (peakṼO2 <12 ml/kg/min). Similar results have been found for ventilation and heart rate. Of note, the slope of the relationship between ṼO2 at 6MWT, reported as percentage of CPET peakṼO2 vs. 6MWT ṼO2 reported as absolute value, progressively increased as exercise limitation did. Conclusions 6MWT must be perceived as a maximal or even supra-maximal exercise activity at least in patients with severe exercise limitation from HF. Our findings should influence the safety procedures needed for the 6MWT in HF.

Comparison between PtCO2 and PaCO2 and Derived Parameters in Heart Failure Patients during Exercise: A Preliminary Study

Evaluation of arterial carbon dioxide pressure (PaCO2) and dead space to tidal volume ratio (VD/VT) during exercise is important for the identification of exercise limitation causes in heart failure (HF). However, repeated sampling of arterial or arterialized ear lobe capillary blood may be clumsy. The aim of our study was to estimate PaCO2 by means of a non-invasive technique, transcutaneous PCO2 (PtCO2), and to verify the correlation between PtCO2 and PaCO2 and between their derived parameters, such as VD/VT, during exercise in HF patients. 29 cardiopulmonary exercise tests (CPET) performed on a bike with a ramp protocol aimed at achieving maximal effort in ≈10 min were analyzed. PaCO2 and PtCO2 values were collected at rest and every 2 min during active pedaling. The uncertainty of PCO2 and VD/VT measurements were determined by analyzing the error between the two methods. The accuracy of PtCO2 measurements vs. PaCO2 decreases towards the end of exercise. Therefore, a correction to PtCO2 that keeps into account the time of the measurement was implemented with a multiple regression model. PtCO2 and VD/VT changes at 6, 8 and 10 min vs. 2 min data were evaluated before and after PtCO2 correction. PtCO2 overestimates PaCO2 for high timestamps (median error 2.45, IQR −0.635–5.405, at 10 min vs. 2 min, p-value = 0.011), while the error is negligible after correction (median error 0.50, IQR = −2.21–3.19, p-value > 0.05). The correction allows removing differences also in PCO2 and VD/VT changes. In HF patients PtCO2 is a reliable PaCO2 estimation at rest and at low exercise intensity. At high exercise intensity the overall response appears delayed but reproducible and the error can be overcome by mathematical modeling allowing an accurate estimation by PtCO2 of PaCO2 and VD/VT.

Time course of exercise capacity in patients recovering from COVID-19-associated pneumonia

Objective: High prevalences of muscle weakness and impaired physical performance in hospitalized patients recovering from COVID-19-associated pneumonia have been reported. Our objective was to determine whether the level of exercise capacity after discharge would affect long-term functional outcomes in these patients. Methods: From three to five weeks after discharge from acute care hospitals (T0), patients underwent a six-minute walk test (6MWT) and were divided into two groups according to the distance walked in percentage of predicted values: <75% group and =75% group. At T0 and three months later (T1), patients completed the Short Physical Performance Battery and the Euro Quality of Life Visual Analogue Scale, and pulmonary function and respiratory muscle function were assessed. In addition, a repeat 6MWT was also performed at T1. Results: At T0, 6MWD values and Short Physical Performance Battery scores were lower in the <75% group than in the =75% group. No differences were found in the Euro Quality of Life Visual Analogue Scale scores, pulmonary function variables, respiratory muscle function variables, length of hospital stay, or previous treatment. At T1, both groups improved their exercise capacity, but only the subjects in the <75% group showed significant improvements in dyspnea and lower extremity function. Exercise capacity and functional status values returned to predicted values in all of the patients in both groups. Conclusions: Four weeks after discharge, COVID-19 survivors with exercise limitation showed no significant differences in physiological or clinical characteristics or in perceived health status when compared with patients without exercise limitation. Three months later, those patients recovered their exercise capacity.

Lancisi’s Sign: Giant C-V waves with Severe Tricuspid Regurgitation in Isolated Tricuspid Valve Prolapse

IIntroduction Isolated tricuspid valve prolapse (TVP) is a rare finding on transthoracic echocardiography. Right atrial enlargement or prominent ” v ” waves as a consequence of hemodynamic changes in severe tricuspid regurgitation (TR) are rarely seen with isolated TVP. Here is a case of isolated prolapse of anterior tricuspid leaflet presenting with giant C-V waves also known as Lancisi’s sign. Case Report A 66-year-old male presented with increasing exercise limitation and leg edema in recent months and was complaining about the persistent pulsation at his neck and elevated jugular venous pulse with prominent systolic pulsation that represents giant C-V waves, also known as ‘Lancisi’s sign’ consequence of severe TR due to isolated prolapse of the anterior leaflet.The patients’ symptoms resolved completely after tricuspid valve replacement. Discussion TVP is best defined at parasternal short axis view with more than 2 mm atrial displacement (AD) of leaflet/leaflets. TVP can also be detected from four chamber view with more than 2 mm AD or in right ventricular inflow view with more than 4 mm AD. As a consequence of TVP, the physiological jugular venous waveform alters due to severe TR.During severe TR; retrograde blood flow through right atrium during ventricular systole restrains x descent and produces a fusion of c and v waves that appears as a large pulsation in physical examination called as ‘Lancisi’s sign’ Conclusion ‘Lancisi’s sign’ is defined as a large visible systolic neck pulsation as a consequence of the c-v waves fusion by preventing x descent during severe TR.

Portable High-Flow Nasal Oxygen during Walking in Patients with Severe Chronic Obstructive Pulmonary Disease: A Randomized Controlled Trial

<b><i>Background:</i></b> High-flow nasal oxygen (HFNO) improves exercise capacity, oxygen saturation, and symptoms in patients with chronic obstructive pulmonary disease (COPD). Due to the need of electricity supply, HFNO has not been applied during free ambulation. <b><i>Objective:</i></b> We evaluated whether HFNO delivered during walking by a battery-supplied portable device was more effective than usual portable oxygen in improving exercise capacity in patients with COPD and severe exercise limitation. The effects on 6-min walking tests (6MWTs) were the primary outcome. <b><i>Methods:</i></b> After a baseline 6MWT, 20 stable patients requiring an oxygen inspiratory fraction (FiO₂) &#x3c;0.60 during exercise, randomly underwent 2 6MWT carrying a rollator, under either HFNO with a portable device (HFNO test) or oxygen supplementation by a Venturi mask (Control) at isoFiO₂. Walked distance, perceived dyspnea, pulse oximetry, and inspiratory capacity at end of the tests as well as patients’ comfort were compared between the tests. <b><i>Results:</i></b> As compared to baseline, walked distance improved significantly more in HFNO than in the control test (by 61.1 ± 37.8 and 39.7 ± 43.8 m, respectively, <i>p</i> = 0.01). There were no significant differences between the tests in dyspnea, peripheral oxygen saturation, or inspiratory capacity, but HFNO test was appreciated as more comfortable. <b><i>Conclusion:</i></b> In patients with COPD and severe exercise limitation, HFNO delivered by a battery-supplied portable device was more effective in improving walking distance than usual oxygen supplementation.

Remote exposure to secondhand tobacco smoke is associated with lower exercise capacity through effects on oxygen pulse- a proxy of cardiac stroke volume

Background: Prolonged past exposure to secondhand tobacco smoke (SHS) is associated with exercise limitation. Pulmonary factors including air trapping contribute to this limitation but the contribution of cardiovascular factors is unclear. Methods: To determine contribution of cardiovascular mechanisms to SHS-associated exercise limitation, we examined the cardiovascular responses to maximum effort exercise testing in 166 never-smokers with remote but prolonged occupational exposure to SHS and no known history of cardiovascular disease except nine with medically-controlled hypertension. We estimated the contribution of oxygen-pulse (proxy for cardiac stroke volume) and changes in systolic (SBP) and diastolic blood pressures (DBP) and heart rate (HR) over workload towards exercise capacity, and examined whether the association of SHS with exercise capacity was mediated through these variables. Results: Oxygen consumption (VO2Peak) and oxygen-pulse (O2-PulsePeak) at peak exercise were 1,516±431mL/min (100±23 %predicted) and 10.6±2.8mL/beat (117±25 %predicted), respectively, with 91 (55%) and 43 (26%) of subjects not being able to achieve their maximum predicted values. Sixty-two percent showed hypertensive response to exercise by at least one established criterion. In adjusted models, VO2Peak was associated directly with O2-Pulse and inversely with rise of SBP and DBP over workload (all P<0.05). Moreover, SHS exposure association with VO2Peak was mainly (84%) mediated through its effect on oxygen-pulse (P=0.034). Notably, although not statistically significant, a large proportion (60%) of air trapping effect on VO2Peak seemed to be mediated through oxygen-pulse (P=0.066). Discussion: In a never-smoker population with remote prolonged exposure to SHS, abnormal escalation of afterload and an SHS-associated reduction in cardiac output contributed to lower exercise capacity.

Utility of Cardiopulmonary Exercise Testing (CPET) in the Post-COVID-19 Context: Retrospective Analysis of a Single Centre Experience.

Cardiopulmonary exercise testing (CPET) allows objective assessment of a patient’s global response to maximal incremental exercise. CPET has been proposed to have a role in investigating post-COVID syndrome. However, CPET is resource intensive, and essential for restoration of other clinical services (e.g. cancer surgery). The aim of this study was to explore utility of CPET in assessing functional status of COVID-19 survivors with persistent dyspnoea. Of the 600 patients reviewed in a post-COVID-19 assessment clinic between May 2020 and April 2021, 12 (male/female: 8/4; age: 4±15.2 years; BMI: 32.8±5.9 kg/m2; non-smokers/ smokers: 8/4) were referred for CPET due to persistent breathlessness out-keeping with disease severity. Of these patients, 10 patients demonstrated reduced peak VO2, whilst five had an exercise limitation attributed to physical deconditioning. Two patients had mainly a cardiac limitation to exercise, with a further three patients demonstrating breathing pattern disorder, pulmonary vascular disease and lung disease. The findings of this single-centre study suggest that intensive CPET testing may not add substantial additional clinical information to aid patient investigation/management in the context of post-COVID. Such resource intensive procedures may be better utilised in selected patients and in the restoration of NHS services following the COVID-19 pandemic.