Is central nervous system processing altered in patients with heart failure?

• Published in: European heart journal Vol. 25; no. 11; pp. 952 - 962
• Main Authors: Rosen, Stuart D., Murphy, Kevin, Leff, Alexander P., Cunningham, Vincent, Wise, Richard J.S., Adams, Lewis, Coats, Andrew J.S., Camici, Paolo G.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.06.2004; Oxford Publishing Limited (England)
• Subjects: 10pt; Aged; ANOVA analysis of variance; ANS autonomic nervous system; Autonomic nervous system; Biological and medical sciences; Brain; Breathlessness; Cardiac Output, Low - complications; Cardiac Output, Low - physiopathology; Cardiology. Vascular system; Central Nervous System Diseases - complications; Central Nervous System Diseases - physiopathology; Cerebral blood flow; Cerebrovascular Circulation - physiology; CHF chronic heart failure; CNS central nervous system; Dyspnea - etiology; Dyspnea - physiopathology; ECG electrocardiogram; Exercise; Exercise - physiology; fR respiratory frequency; gCBF global cerebral blood flow; Heart; Heart failure; Heart failure, cardiogenic pulmonary edema, cardiac enlargement; Humans; Hyperventilation - complications; Hyperventilation - physiopathology; legalpaper]{article} ßusepackage{amssymb} ßusepackage{amsfonts} ßusepackage{amsmath} ßpagestyle{empty} ßbegin{document} ß(Pß) ßend{document}CO2 partial pressure of carbon dioxide; legalpaper]{article} ßusepackage{amssymb} ßusepackage{amsfonts} ßusepackage{amsmath} ßpagestyle{empty} ßbegin{document} ß(V_{ßmathrm{CO}_{2}}ß) ßend{document} slope ventilatory equivalent for CO2; legalpaper]{article} ßusepackage{amssymb} ßusepackage{amsfonts} ßusepackage{amsmath} ßpagestyle{empty} ßbegin{document} ß(V_{ßmathrm{CO}_{2}}ß) ßend{document} volume of CO2 exhaled; Male; Medical sciences; Middle Aged; Perception; PET positron emission tomography; Positron emission tomography; rCBF regional cerebral blood flow; SaO2 arterial oxygen saturation; SPM statistical parametric mapping; Tomography, Emission-Computed; VE minute ventilation; VE–ßbatchmode ßdocumentclass[fleqn; vs versus; VT tidal volume; ßbatchmode ßdocumentclass[fleqn; Radionuclide study; Physical exercise; Human; Heart failure; Brain; Breathlessness; Central nervous system; Cardiovascular disease; Blood flow; Encephalon; Exercise; Autonomic nervous system; Cerebral blood flow; Heart disease; Exercise tolerance test; Hemodynamics; Positron emission tomography; Emission tomography
• ISSN: 0195-668X; 1522-9645
• DOI: 10.1016/j.ehj.2004.03.025

Aims Breathlessness is a cardinal symptom of heart failure and the altered regulation of breathing is common. The contribution of abnormal central nervous system activity has not previously been investigated directly, although abnormal autonomic responses have been described. Our aim was to assess whether heart failure patients exhibit different patterns of regional brain activation after exercise stress. Methods We used positron emission tomography with H215O, to measure changes in regional cerebral blood flow (rCBF) and absolute global cerebral blood flow (gCBF) in 6 male class II/III heart failure patients and 6 normal controls. Breathlessness (0–5 visual analogue scale) and respiratory parameters were measured at rest, after horizontal bicycle exercise and during isocapnic hyperventilation. CBF was measured in each condition in all subjects. Results Both groups were similarly breathless after exercise and the respiratory parameters were comparable. rCBF differences for the main comparison (exercise vs hyperventilation) were: activation of the right frontal medial gyrus (\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(P{<}0.001,Z=4.90\) \end{document}) and left precentral gyrus (\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(P{<}0.03,Z=4.66\) \end{document}) in controls but not in patients. Both groups had rCBF increases in the left anterior cingulate (\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(P{<}0.05,Z=4.67\) \end{document}) and right dorsal cingulate cortex (\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(P{<}0.05,Z=4.66\) \end{document}). The gCBF did not differ between exercise, isocapnic hyperventilation and rest in patients but, in controls, gCBF was greater after exercise compared to either isocapnic hyperventilation or rest. Conclusion Heart failure patients had a distinct pattern of regional cortical activity with exercise-induced breathlessness but unvarying CBF values between conditions. These central neural differences in activity may contribute to some features of heart failure, such as variability in symptoms and autonomic dysregulation.