Near-maximal fractional oxygen extraction by active  skeletal muscle in patients with chronic heart failure

Katz, Stuart D.; Maskin, Carol S.; Jondeau, Guillaume; Cocke, Thomas; Berkowitz, Robert; LeJemtel, Thierry H.

doi:10.1152/jappl.2000.88.6.2138

Cited by 71 publications

(52 citation statements)

References 28 publications

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“…Patients with CHF lack the normal physiological reserve to compensate for decreased hemoglobin and may manifest decreased aerobic capacity in response to mild degrees of anemia. 24) Erythropoietin is the most important hormone for erythropoiesis, and is produced from specialized peritubular fibroblasts situated within the cortex and outer medulla in the kidney, in a sensitive manner in response to hypoxia and low renal blood flow. 25) In CHF patients, renal blood flow and eGFR are decreased 24) and the erythropoietin level is increased with the severity of heart failure.…”

Section: Discussionmentioning

confidence: 99%

“…24) Erythropoietin is the most important hormone for erythropoiesis, and is produced from specialized peritubular fibroblasts situated within the cortex and outer medulla in the kidney, in a sensitive manner in response to hypoxia and low renal blood flow. 25) In CHF patients, renal blood flow and eGFR are decreased 24) and the erythropoietin level is increased with the severity of heart failure. 26) However, this increase could not raise hemoglobin to levels high enough to obtain adequate oxygenation for CHF patients, and ESAs were used for the therapeutic target in CHF patients with anemia.…”

Section: Discussionmentioning

confidence: 99%

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Adaptive Servo-Ventilation Therapy Improves Long-Term Prognosis in Heart Failure Patients With Anemia and Sleep-Disordered Breathing

et al. 2014

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SummarySleep disordered breathing (SDB) and anemia influences the progression of chronic heart failure (CHF). Adaptive servo-ventilation (ASV) is an effective therapeutic device for treatment of CHF, however, the impacts of ASV on CHF patients with or without anemia remain unclear.A total of 139 patients with CHF and SDB were divided into two groups: those treated with ASV (n = 53) and without ASV (n = 86). All patients were prospectively followed after discharge with the endpoints of cardiac death or progressive heart failure requiring rehospitalization. There were 65 patients (47%) with anemia among all subjects. The apnea hypopnea index was improved, and plasma BNP and high sensitive C-reactive protein levels were decreased in both groups with and without anemia by ASV therapy. The Kaplan-Meier survival curve demonstrated that the cardiac event-free rate in patients with ASV was significantly higher than in those without ASV in the anemia group (P = 0.008). However, in the non-anemia group, the cardiac event-free rate was similarly high in patients both with and without ASV (P = 0.664). Multivariate Cox proportional hazard analysis demonstrated that ASV use was an independent predictor of cardiac events in the anemia group (P = 0.0308), but not in the non-anemia group.ASV treatment for CHF and SDB has more favorable impacts in patients with anemia than in those without anemia. (Int Heart J 2014; 55: 342-349)

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Adaptive Servo-Ventilation Therapy Improves Long-Term Prognosis in Heart Failure Patients With Anemia and Sleep-Disordered Breathing

et al. 2014

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“…Nine participants (four women) completed symptom-limited tests, after which three had definitive surgery and six were referred for palliative treatment. [2][3][4][5][6][7][8][9][10][11][12][13][14]) days, at which time all participants were still jaundiced. Oxygen consumption and oxygen pulse increased during exercise (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Weber and Janicki demonstrated that peripheral oxygen extraction was normal at peak exercise in patients with varying degrees of heart failure [6]. Reduced oxygen delivery causes tissue ischaemia, lactic acidosis and a rightward shift of the oxyhaemoglobin dissociation curve (Bohr effect), driving peripheral oxygen extraction in patients with heart failure [14].Participants had raised ventilatory equivalents for carbon dioxide, which, without a history of lung disease, abnormal spirometry or arterial desaturation, suggests left ventricular failure [15]. The low oxygen pulses exhibited by participants do not differentiate hypovolaemia from intrinsic cardiac dysfunction.…”

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confidence: 99%

Peripheral oxygen extraction in patients with malignant obstructive jaundice

2013

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SummaryMalignant obstructive jaundice is associated with poor aerobic capacity. We measured oxygen consumption and oxygen extraction (arterial-venous oxygen content) in the legs of nine patients during cardiopulmonary exercise testing before pancreaticoduodenectomy. The median (IQR [range]) peak oxygen consumption was 67 (49-77 [32-84])% of predicted. Normal patterns of oxygen extraction were seen with increasing power towards lactate threshold. Near maximal oxygen extraction occurred at peak exercise. Femoral venous oxygen pressure and saturation exceeded baseline values whilst recovering from exercise. These findings suggest that peripheral oxygen extraction is normal during exercise in patients with malignant obstructive jaundice. The primary limitation in oxygen consumption is reduced oxygen delivery. We observed that patients with obstructive jaundice, presenting for major hepato-pancreatico-biliary surgery, were often unfit on cardiopulmonary exercise testing (CPET), with less than expected oxygen consumptions at peak exercise and at the lactate threshold. Reduced oxygen consumption may be due to reduced delivery or reduced extraction.Our patients did not have documented heart disease or abnormal resting trans-thoracic echocardiograms, but these do not exclude contractile dysfunction. Clinical studies have demonstrated that raised bilirubin is associated with raised endotoxin and inflammatory cytokine levels [1][2][3], as well as cardiovascular dysfunction characterised by hypovolaemia and reduced left ventricular systolic function [4,5]. Weber and Janicki demonstrated maximal peripheral oxygen extraction (> 70%) in patients with varying degrees of heart failure during exercise [6]. The authors demonstrated that reduced cardiac output was the primary cause of reduced aerobic capacity rather than impaired oxygen extraction. Stringer et al. showed that femoral venous oxygen saturation continues to fall after the lactate threshold but without a fall in femoral venous oxygen pressure, due to the rightshift of the haemoglobin dissociation curve in response to metabolic acidosis [7]. These changes represent normal microcirculatory responses to reduced oxygen delivery.Resuscitated septic patients have increased cardiac output, increased oxygen delivery and increased oxygen consumption [8][9][10]. However, the increase in oxygen delivery exceeds the increase in oxygen consumption, due to decreased oxygen extraction (the arterial -venous difference in oxygen content). 32© 2013 The Association of Anaesthetists of Great Britain and Ireland Anaesthesia 2014Anaesthesia , 69, 32-36 doi:10.1111 We hypothesised that poor exercise capacity in patients with obstructive jaundice was, like in septic patients, secondary to reduced oxygen extraction and a normal or raised cardiac output. MethodsThe Institutional and regional ethics committee approved the recruitment of 10 patients to this invasive pilot study. All participants provided written informed consent.We included patients eligible for pancreaticoduodenectomy, with el...

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“…This abnormality can lead to impairment of extraction of oxygen from muscle capillaries and should be reflected in abnormally high values of S v O 2 at end-exercise [11]. However, data from studies in heart failure [12] and published in abstract form in PAH [13] suggest that this is not the case. Thus, although muscle dysfunction is present in PAH, the diffusion capacity for oxygen from the capillaries to the mitochondria still more than matches the reduced level of oxygen delivery to the capillaries.…”

Section: Introductionmentioning

confidence: 99%

The Role of Exercise Testing in the Modern Management of Pulmonary Arterial Hypertension

Johnson

Thomson

2014

Diseases

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A culture of exercise testing is firmly embedded in the management of pulmonary arterial hypertension (PAH) but its clinical relevance and utility have recently been under some debate. The six minute walk test (6MWT) has been used as a primary outcome measure to enable the licensing of many of the medications used for this condition. Recent reviews have questioned the validity of this test as a surrogate of clinical outcomes. At the same time, other questions are emerging where exercise testing may be the solution. With the rise in understanding of genetic markers of idiopathic PAH (IPAH), the screening of an otherwise healthy population for incipient pulmonary hypertension (PH) will be required. The proliferation in treatment choices and identification of populations with PH where PAH treatment is not indicated, such as left heart and lung disease, requires more definitive differentiation from patients with PAH. There is a continuing question about the existence and clinical relevance of exercise induced PAH as a cause of unexplained dyspnoea and fatigue and as a latent phase of resting PH. This review presents a summary and critical analysis of the current role of exercise testing in PAH and speculates on future trends.

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Near-maximal fractional oxygen extraction by active skeletal muscle in patients with chronic heart failure

Cited by 71 publications

References 28 publications

Adaptive Servo-Ventilation Therapy Improves Long-Term Prognosis in Heart Failure Patients With Anemia and Sleep-Disordered Breathing

Adaptive Servo-Ventilation Therapy Improves Long-Term Prognosis in Heart Failure Patients With Anemia and Sleep-Disordered Breathing

Peripheral oxygen extraction in patients with malignant obstructive jaundice

The Role of Exercise Testing in the Modern Management of Pulmonary Arterial Hypertension

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