Determination of the VE/VCO2 Slope from a Constant Work-Rate Exercise Test in Cardiac Patients

Abstract

Abstract:Incremental exercise testing to a symptom-limited maximum has been used to measure the ratio of the increase in ventilation (V . E) to the increase in CO 2 output (V . CO 2 ) during exercise (V . E/V . CO 2 slope), a valuable index reflecting the severity of the ventilation-perfusion mismatch in heart failure. Here we studied whether this same value for the slope of V . E/V . CO 2 could be determined from a short constant work-rate exercise test of moderate intensity. Twenty-three patients with a previous myocardial infarction underwent moderate-intensity (69 ± 15 W) constant work-rate exercise for 6 min and an incremental work-rate exercise test to the max. The V . E/V . CO 2 slope was calculated from the incremental exercise test from the start of increasing the work-rate to the ventilatory compensation point.The V . E/V . CO 2 slope was similarly calculated from the start of constant work-rate exercise until the 4th minute, when V . E and V . CO 2 changed minimally. The V . E/V . CO 2 slope determined from incremental exercise was 33.8 ± 5.9, ranging from 20.9 to 42.8. The slope obtained from constant work-rate exercise was 32.9 ± 5.7. The V . E/V . CO 2 slopes obtained from the two exercise tests did not differ significantly. The slope obtained from constant work-rate exercise was significantly positively correlated with the slope obtained from the incremental exercise ( r = 0.84, p < 0.0001). The V . E/V . CO 2 slope can be determined from constant work-rate exercise at a moderate intensity. This indicates that the relationship between ventilation and CO 2 output is consistent and independent of the mode of exercise testing.

Integrative Pan-Cancer Analysis Reveals Decreased Melatonergic Gene Expression in Carcinogenesis and RORA as a Prognostic Marker for Hepatocellular Carcinoma

“…Meanwhile, all except for one of the differentially expressed melatonergic genes were underexpressed in KIRC, LIHC, LUAD, and STAD. Notably, the synthetic gene, ASMT, and metabolic gene, CYP1A1, were both highly expressed in COAD; notably, the gastro intestinal tract is an extra-pineal source of melatonin production during the daytime (46). Additionally, the metabolic gene, CYP1B1, was overexpressed in LIHC, possibly because the liver is the main site for metabolism of melatonin (1).…”

Monosodium L-glutamate and fats change free fatty acid concentrations in intestinal contents and affect free fatty acid receptors express profile in growing pigs

“…Previous studies have demonstrated that the role of FFAs in human health is sensed and regulated by FFA receptors (74), and these FFA receptors play an essential role in lipid and energy metabolism, insulin resistance, fat accumulation, and even pathogenesis of obesity and diabetes (14, 28, 29). FFA receptors are divided into SCFA receptors (GPR41 and GPR43) (23) and LCFA receptors (GPR40, GPR84 and GPR120) (22, 27) and then regulate the corresponding FFAs biological function, respectively. Additionally, SCFAs activate GPR41 and GRP43 cascade signal pathways, which lead the release of gastrointestinal hormone peptide YY, and further regulate energy metabolism (75).…”

“…The effect of FFAs is finely regulated by fatty acid receptors, which subsequently activate downstream signalling cascade, and finally affecting host physiological as well as immune function (22). The most extensively identified FFAs receptors belong to G protein-coupled receptor (GRP) and mainly include GPR40, GPR41, GPR43, GPR84, GPR119 and GPR120 (23–26). Many compelling investigations had shown that FFAs receptors were related with lipid metabolism, immunity and pathogenesis of obesity, chronic inflammation and diabetes (27, 28).…”

Artan Yüke Karşı Egzersiz Testi Sırasında Solunum Etkinliğinin Antrenmanlı ve Sedanter Erkek Deneklerde Karşılaştırılmalı İncelenmesi

“…Farklı iş gücü artış protokollerinin solunum etkinliğinin hesaplanması üzeri-ne etkisi olmadığını gösterilmiştir (29). Yapılan çalışma-larda sabit yük egzersiz testleri kullanılarak da solunum etkinliğinin hesaplanabileceği gösterilmiştir (5,30). Bu VE/VCO2 değerinin 34 ve üstünde olduğu kalp ve solunum sistemi problemi olan vakalarda yüksek bir ölüm riski içerdiği, bu değerin 34 altına geldiği durumlarda riskin azaldığını gösteren prognostik açıdan önemli bir değer olarak karşımıza çıkmaktadır (31).…”