Oxygen saturation

Author(s):  
William J.M. Kinnear ◽  
James H. Hull

This chapter describes how desaturation during a cardiopulmonary exercise test (CPET) is uncommon. A fall of more than 4% from resting values is considered abnormal. Oxygen desaturation is usually caused by lung or pulmonary vascular disease, reflecting ventilation–perfusion inequality or impaired diffusion. Occasionally, a right-to-left shunt will open up in the heart during exercise. Some elite athletes show exercise-induced arterial hypoxaemia, when the ability of their muscles to utilize oxygen cannot be met by the subject’s ventilatory capacity.

2021 ◽  
Vol 23 (Supplement_G) ◽  
Author(s):  
Federica Re ◽  
Geza Halasz ◽  
Francesco Moroni ◽  
Matteo Beltrami ◽  
Pasquale Baratta ◽  
...  

Abstract Aims Pulmonary arterial hypertension (PAH) has been described in patients with hypertrophic cardiomyopathy (HCM) and it was associated with a worse prognosis. Nevertheless in most HCM patients, despite normal pulmonary pressures at rest, congestive symptoms are elicited by exercise. In the present study, combining cardiopulmonary exercise test (CPET) with echocardiography, we aimed to evaluate the presence of exercise-induced pulmonary hypertension (EiPAH) its role in functional limitation and its prognostic significance in a cohort of patients with obstructive and non-obstructive HCM. Methods and results 182 HCM patients (35% females, mean age 47.5 ± 15.9) undergoing CPET. During CPET, LVOT velocities and trans-tricuspid gradient were measured. Thirty-seven patients (20%) developed sPAP > 40 mmHg at peak exercise (EiPAH). EiPAH was associated with an lower exercise performance, larger left atrial volumes, higher left ventricular gradient and higher VE/VCO2 slope .At multivariable model baseline sPAP (P < 0.0001) and baseline left ventricular obstruction (LVOT) (P = 0.028) were significantly associated with EiPAH .Kaplan-Meier curve analysis showed EiPAH was a significant predictor of HCM –related morbidity (hazards ratio: 6.21, 95% CI: 1.47–26.19; P = 0.05; 4.21, 95% CI: 1.94–9.12; P < 0.001) for the primary and the secondary endpoint respectively. Conclusions EiPAH was present in about one fifth of HCM patients without evidence of elevated pulmonary pressures at rest, and was associated with adverse clinical outcome. Diagnosing EiPAH by exercise echo/CPET may help physicians to detect early stage of PAH requiring a closer clinical monitoring and individualized treatment strategies.


Author(s):  
Magnus Bjørkavoll‐Bergseth ◽  
Christine Bjørkvik Erevik ◽  
Øyunn Kleiven ◽  
Thijs M. H. Eijsvogels ◽  
Øyvind Skadberg ◽  
...  

Background Postexercise cardiac troponin levels show considerable interindividual variations. This study aimed to identify the major determinants of this postexercise variation in cardiac troponin I (cTnI) following 3 episodes of prolonged high‐intensity endurance exercise. Methods and Results Study subjects were recruited among prior participants in a study of recreational cyclists completing a 91‐km mountain bike race in either 2013 or 2014 (first race). In 2018, study participants completed a cardiopulmonary exercise test 2 to 3 weeks before renewed participation in the same race (second race). Blood was sampled before and at 3 and 24 hours following all exercises. Blood samples were analyzed using the same Abbot high‐sensitivity cTnI STAT assay. Fifty‐nine individuals (aged 50±9 years, 13 women) without cardiovascular disease were included. Troponin values were lowest before, highest at 3 hours, and declining at 24 hours. The largest cTnI difference was at 3 hours following exercise between the most (first race) (cTnI: 200 [87–300] ng/L) and the least strenuous exercise (cardiopulmonary exercise test) (cTnI: 12 [7–23] ng/L; P <0.001). The strongest correlation between troponin values at corresponding times was before exercise ( r =0.92, P <0.0001). The strongest correlations at 3 hours were between the 2 races ( r =0.72, P <0.001) and at 24 hours between the cardiopulmonary exercise test and the second race ( r =0.83, P <0.001). Participants with the highest or lowest cTnI levels showed no differences in race performance or baseline echocardiographic parameters. Conclusions The variation in exercise‐induced cTnI elevation is largely determined by a unique individual cTnI response that is dependent on the duration of high‐intensity exercise and the timing of cTnI sampling. Registration URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02166216 .


2020 ◽  
Vol 9 (6) ◽  
pp. 1910
Author(s):  
Rosalinda Madonna ◽  
Riccardo Morganti ◽  
Francesco Radico ◽  
Piergiusto Vitulli ◽  
Marco Mascellanti ◽  
...  

Background and Aim: Isolated exercise-induced pulmonary hypertension (ExPH) associates with cardiovascular (CV) events in patients with left heart disease. We investigated its prognostic significance in scleroderma patients at risk for pulmonary arterial hypertension (PAH). Methods: In 26 consecutive scleroderma female patients with either low (n = 13) or intermediate probability (n = 13) of pulmonary hypertension (PH) at rest, we evaluated, both at time 0 and 1 year, prognostic determinants of CV risk: onset or progression of heart failure/syncope; worsening of functional class; functional performance at the 6-minute walking test and at cardiopulmonary exercise test; right atrial area; and pericardial effusion. We assigned a severity score 1–3 to each prognostic determinant, derived an overall CV risk score, and its 0–1 year change. Isolated ExPH during the cardiopulmonary exercise test (CPET) was defined as absence of PH at rest, reduced peak VO2, VE/VCO2 >30 at anaerobic threshold, reduced O2 pulse, and ΔVO2/ΔW <9 mL/min/W. We then correlated ExPH at time 0 with clinical worsening (risk score increase >20% after 1 year). Results: ExPH was strongly associated with clinical worsening compared to patients without ExPH (p = 0.005). In patients without ExPH, none had > 20% increased CV risk score after 1 year. Conversely, about 50% of patients with ExPH had such an increase, suggesting a worsening of prognosis. Conclusions: Isolated ExPH associates with higher cardiovascular risk and thus clinical worsening in scleroderma patients. The assessment of ExPH by CPET can thus contribute to a better risk stratification and the planning of a more adequate follow-up.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
T Chwyczko ◽  
L Zalucka ◽  
E Smolis-Bak ◽  
I Kowalik ◽  
E Noszczak ◽  
...  

Abstract Background Rehabilitation after LVAD implantation is increasingly used. We developed the novel method of comprehensive rehabilitation starting directly after LVAD implantation. Study group 21 recent LVAD (15 Heart Mate III, 6 HeartWare) recipients (56.2±11.7 yrs, 100% men) were included to 5-week rehabilitation program, which included supervised endurance training on cycloergometer (5 times per week), resistance training, general fitness exercises with elements of equivalent and coordination exercises (every day). 6-minute walking test (6MWT), cardiopulmonary exercise test (CPET) and prognostic biomarkers: NT-proBNP, Galectin-3 and ST2 were investigated at the beginning and at the end of rehabilitation program. Results See Table 1. At the end of rehabilitation program, significant increase in 6MWT distance, maximum workload, peak VO2 and upward shift of anaerobic threshold in CPET were observed in all patients. Significant reductions of NTproBNP, ST2 and galectin-3 levels were observed. There were no major adverse events during rehabilitaton. Conclusions Comprehensive novel rehabilitation in LVAD recipients is safe and results in significant improvement of 6-minutes walking test distance and cardiopulmonary exercise test results. Moreover, this novel rehabilitation program reduces levels of prognostic biomarkers of heart failure: NT-proBNP, Galectin-3 and ST2. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Center for Research and Development - STRATEGMED II project


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