0000000000667831

AUTHOR

Roland Wensel

Exercise hyperventilation in chronic heart failure is not caused by systemic lactic acidosis

Background: Patients with heart failure have an abnormally high ventilatory response to exercise associated with gas exchange defects and reduced arterial pCO2. Aims: We examined the possibility of lactic acidosis as the stimulus to this increased ventilation that abnormally depresses pCO2 during exercise in heart failure. Method and results: We studied 18 patients with chronic heart failure. We measured VE/VCO2 slope during exercise, arterial blood gases and lactate concentrations during cardiopulmonary exercise testing (rest, peak exercise and one minute after the end of exercise). Neither VE/VCO2 slope nor arterial pCO2 were related to arterial lactate concentrations at peak exercise (r=…

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Pathophysiologic quantities of endotoxin-induced tumor necrosis factor-alpha release in whole blood from patients with chronic heart failure.

Bacterial endotoxin activity is elevated in patients with decompensated chronic heart failure (HF) and acts as a potent stimulus for immune activation. We sought to determine whether endotoxin, at an activity level seen in vivo (around 0.6 EU/ml), is sufficient to stimulate the secretion of tumor necrosis factor-alpha (TNF-alpha) and TNF-alpha soluble receptor (sTNFR2) in ex vivo whole blood from patients with HF. We studied 15 patients with HF (aged 65 +/- 1.9 years, New York Heart Association class 2.1 +/- 0.3, left ventricular ejection fraction 31 +/- 5%; mean +/- SEM), of whom 5 had cardiac cachexia, and 7 healthy control subjects (59 +/- 5 years, p = NS). Reference endotoxin was added …

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Differential contribution of dead space ventilation and low arterial pCO2 to exercise hyperpnea in patients with chronic heart failure secondary to ischemic or idiopathic dilated cardiomyopathy

In chronic heart failure (CHF), the abnormally large ventilatory response to exercise (VE/VCO(2) slope) has 2 conceptual elements: the requirement of restraining arterial partial pressure of carbon dioxide (pCO(2)) from increasing (because of an increased ratio between increased physiologic dead space and tidal volume [VD/VT]) and the depression of arterial pCO(2) by further increased ventilation, which necessarily implies an important non-carbon dioxide stimulus to ventilation. We aimed to assess the contribution of these 2 factors in determining the elevated VE/VCO(2) slope in CHF. Thirty patients with CHF underwent cardiopulmonary exercise testing (age 65 +/- 11 years, left ventricular e…

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The anti-CD14 antibody IC14 suppresses ex vivo endotoxin stimulated tumor necrosis factor-alpha in patients with chronic heart failure

Background: Activation of the endotoxin (LPS) receptor, CD14, leads to tumor necrosis factor-alpha (TNF) production. Plasma LPS activity is elevated in patients with severe chronic heart failure (CHF). An anti-CD14 antibody, IC14, blocks TNF production in healthy volunteers. It is not known whether IC14 prevents TNF production in CHF patients. Methods and results: Blood from 20 CHF patients (age 64±2.1 years, NYHA class 2.2±0.1, LVEF 27±3%, mean±SEM) was pre-incubated with 0.5, 1.0, 5.0, 10 and 50 μg/mL IC14 for 1 h followed by incubation with 1 or 10 ng/mL LPS for 6 h. Fourteen subjects served as controls (58±2.4 years). LPS-stimulated TNF release was 76% and 60% greater at 1 and 10 ng/mL …

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