Cardiac sympathetic responses to acute vasodilation. Normal ventricular function versus congestive heart failure. 1996

G E Newton, and J D Parker
Department of Medicine, Mount Sinai Hospital, University of Toronto, Ontario, Canada.

BACKGROUND Although there is indirect evidence of impaired baroreflex control of sympathetic outflow directed at heart muscle, the regulation of cardiac sympathetic activity in the setting of heart failure is largely unexplored. We used the norepinephrine spillover method to address the hypothesis that baroreflex control of cardiac sympathetic activity is reduced in heart failure. RESULTS Twenty-three patients were studied, 17 in a group with heart failure and 6 in a group with normal ventricular function. In both groups, cardiac norepinephrine spillover was assessed in response to nitroprusside infused to steady-state conditions. Nitroprusside resulted in significant reductions in mean systemic arterial pressure (normal group, -15 +/- 3% [mean +/- SEM]; heart failure group, -13 +/- 1%) and mean pulmonary artery pressure (normal group, -25 +/- 10%; heart failure group, -29 +/- 4%). In response to nitroprusside, there was a 98 +/- 16% increase in cardiac norepinephrine spillover in the normal group (from 81 +/- 10 to 159 +/- 25 pmol/min, P < .05). Despite similar hemodynamic responses to nitroprusside in the heart failure group, there was only a 28 +/- 14% increase in cardiac spillover (from 211 +/- 71 to 245 +/- 59 pmol/ min, P = NS), a response that was significantly smaller than that seen in the normal group. CONCLUSIONS In patients with heart failure compared with subjects with normal ventricular function, there was a significantly smaller increase in cardiac sympathetic activity in response to a steady-state infusion of nitroprusside. This result provides evidence for reduced baroreflex control of cardiac sympathetic activity in heart failure.

UI MeSH Term Description Entries
D008297 Male Males
D008875 Middle Aged An adult aged 45 - 64 years. Middle Age
D009599 Nitroprusside A powerful vasodilator used in emergencies to lower blood pressure or to improve cardiac function. It is also an indicator for free sulfhydryl groups in proteins. Nitroferricyanide,Sodium Nitroprusside,Cyanonitrosylferrate,Ketostix,Naniprus,Nipride,Nipruton,Nitriate,Nitropress,Nitroprussiat Fides,Nitroprusside, Disodium Salt,Nitroprusside, Disodium Salt, Dihydrate,Disodium Salt Nitroprusside,Nitroprusside, Sodium
D009638 Norepinephrine Precursor of epinephrine that is secreted by the ADRENAL MEDULLA and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers, and of the diffuse projection system in the brain that arises from the LOCUS CERULEUS. It is also found in plants and is used pharmacologically as a sympathomimetic. Levarterenol,Levonorepinephrine,Noradrenaline,Arterenol,Levonor,Levophed,Levophed Bitartrate,Noradrenaline Bitartrate,Noradrénaline tartrate renaudin,Norepinephrin d-Tartrate (1:1),Norepinephrine Bitartrate,Norepinephrine Hydrochloride,Norepinephrine Hydrochloride, (+)-Isomer,Norepinephrine Hydrochloride, (+,-)-Isomer,Norepinephrine d-Tartrate (1:1),Norepinephrine l-Tartrate (1:1),Norepinephrine l-Tartrate (1:1), (+,-)-Isomer,Norepinephrine l-Tartrate (1:1), Monohydrate,Norepinephrine l-Tartrate (1:1), Monohydrate, (+)-Isomer,Norepinephrine l-Tartrate (1:2),Norepinephrine l-Tartrate, (+)-Isomer,Norepinephrine, (+)-Isomer,Norepinephrine, (+,-)-Isomer
D011311 Pressoreceptors Receptors in the vascular system, particularly the aorta and carotid sinus, which are sensitive to stretch of the vessel walls. Baroreceptors,Receptors, Stretch, Arterial,Receptors, Stretch, Vascular,Stretch Receptors, Arterial,Stretch Receptors, Vascular,Arterial Stretch Receptor,Arterial Stretch Receptors,Baroreceptor,Pressoreceptor,Receptor, Arterial Stretch,Receptor, Vascular Stretch,Receptors, Arterial Stretch,Receptors, Vascular Stretch,Stretch Receptor, Arterial,Stretch Receptor, Vascular,Vascular Stretch Receptor,Vascular Stretch Receptors
D011651 Pulmonary Artery The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs. Arteries, Pulmonary,Artery, Pulmonary,Pulmonary Arteries
D012016 Reference Values The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality. Normal Range,Normal Values,Reference Ranges,Normal Ranges,Normal Value,Range, Normal,Range, Reference,Ranges, Normal,Ranges, Reference,Reference Range,Reference Value,Value, Normal,Value, Reference,Values, Normal,Values, Reference
D001794 Blood Pressure PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS. Systolic Pressure,Diastolic Pressure,Pulse Pressure,Pressure, Blood,Pressure, Diastolic,Pressure, Pulse,Pressure, Systolic,Pressures, Systolic
D005260 Female Females
D006321 Heart The hollow, muscular organ that maintains the circulation of the blood. Hearts

Related Publications

G E Newton, and J D Parker
May 1996, Circulation,
G E Newton, and J D Parker
July 2007, Acta pharmacologica Sinica,
G E Newton, and J D Parker
September 1988, The American journal of cardiology,
G E Newton, and J D Parker
August 2003, Journal of the American College of Cardiology,
G E Newton, and J D Parker
October 1984, The American journal of cardiology,
G E Newton, and J D Parker
August 1990, Circulation,
G E Newton, and J D Parker
May 1991, The American journal of cardiology,
G E Newton, and J D Parker
September 1996, The American journal of physiology,
Copied contents to your clipboard!