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Functional effects of cardiac sympathetic denervation in neurogenic orthostatic hypotension.
Parkinsonism Relat Disord. 2009 Feb; 15(2):122-7.PR

Abstract

BACKGROUND

Diseases characterized by neurogenic orthostatic hypotension (NOH), such as Parkinson disease (PD) and pure autonomic failure (PAF), are associated with cardiac sympathetic denervation, as reflected by low myocardial concentrations of 6-[(18)F]fluorodopamine-derived radioactivity. We studied the impact of such denervation on cardiac chronotropic and inotropic function.

METHODS

Cardiac inotropic function was assessed by the pre-ejection period index and the systolic time ratio index in response to the directly acting beta-adrenoceptor agonist, isoproterenol, and to the indirectly acting sympathomimetic amine, tyramine, in patients with PD+NOH or PAF (PD+NOH/PAF group, N=13). We compared the results to those in patients with multiple system atrophy, which usually entails NOH with normal cardiac sympathetic innervation (MSA, N=15), and in normal control subjects (N=5).

RESULTS

The innervated and denervated groups did not differ in baseline mean pre-ejection period index or systolic time ratio index. Tyramine increased cardiac contractility in the MSA patients and controls but not in the PD+NOH/PAF group. For similar heart rate responses, the PD+NOH/PAF group required less isoproterenol (p<0.01) and had lower plasma isoproterenol levels (p<0.01) than did the MSA group.

CONCLUSIONS

Among patients with NOH those with cardiac sympathetic denervation have an impaired inotropic response to tyramine and exaggerated responses to isoproterenol. This pattern suggests that cardiac denervation is associated with decreased ability to release endogenous norepinephrine from sympathetic nerves and with supersensitivity of cardiac beta-adrenoreceptors.

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Authors+Show Affiliations

Imrich R
National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA. richard.imrich@savba.sk
Eldadah BA
No affiliation info available
Bentho O
No affiliation info available
Pechnik S
No affiliation info available
Sharabi Y
No affiliation info available
Holmes C
No affiliation info available
Grossman E
No affiliation info available
Goldstein DS
No affiliation info available

MeSH

Adrenergic beta-AgonistsAgedAutonomic Nervous System DiseasesBlood PressureDopamineFemaleHeartHemodynamicsHumansHypotension, OrthostaticIsoproterenolMaleMethoxyhydroxyphenylglycolNorepinephrineParkinson DiseaseRadionuclide ImagingStatistics, NonparametricSympathectomySympathomimeticsTyramine

Pub Type(s)

Journal Article
Research Support, N.I.H., Intramural

Language

eng

PubMed ID

18514012

Clinical Trial Links

Effects of Melatonin to Reduce Nocturnal Hypertension in Patients With Neurogenic Orthostatic Hypotension

Citation

Imrich, Richard, et al. "Functional Effects of Cardiac Sympathetic Denervation in Neurogenic Orthostatic Hypotension." Parkinsonism & Related Disorders, vol. 15, no. 2, 2009, pp. 122-7.
Imrich R, Eldadah BA, Bentho O, et al. Functional effects of cardiac sympathetic denervation in neurogenic orthostatic hypotension. Parkinsonism Relat Disord. 2009;15(2):122-7.
Imrich, R., Eldadah, B. A., Bentho, O., Pechnik, S., Sharabi, Y., Holmes, C., Grossman, E., & Goldstein, D. S. (2009). Functional effects of cardiac sympathetic denervation in neurogenic orthostatic hypotension. Parkinsonism & Related Disorders, 15(2), 122-7. https://doi.org/10.1016/j.parkreldis.2008.04.002
Imrich R, et al. Functional Effects of Cardiac Sympathetic Denervation in Neurogenic Orthostatic Hypotension. Parkinsonism Relat Disord. 2009;15(2):122-7. PubMed PMID: 18514012.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Functional effects of cardiac sympathetic denervation in neurogenic orthostatic hypotension. AU - Imrich,Richard, AU - Eldadah,Basil A, AU - Bentho,Oladi, AU - Pechnik,Sandra, AU - Sharabi,Yehonatan, AU - Holmes,Courtney, AU - Grossman,Ehud, AU - Goldstein,David S, Y1 - 2008/05/29/ PY - 2008/02/04/received PY - 2008/04/08/revised PY - 2008/04/08/accepted PY - 2008/6/3/pubmed PY - 2009/3/27/medline PY - 2008/6/3/entrez SP - 122 EP - 7 JF - Parkinsonism & related disorders JO - Parkinsonism Relat Disord VL - 15 IS - 2 N2 - BACKGROUND: Diseases characterized by neurogenic orthostatic hypotension (NOH), such as Parkinson disease (PD) and pure autonomic failure (PAF), are associated with cardiac sympathetic denervation, as reflected by low myocardial concentrations of 6-[(18)F]fluorodopamine-derived radioactivity. We studied the impact of such denervation on cardiac chronotropic and inotropic function. METHODS: Cardiac inotropic function was assessed by the pre-ejection period index and the systolic time ratio index in response to the directly acting beta-adrenoceptor agonist, isoproterenol, and to the indirectly acting sympathomimetic amine, tyramine, in patients with PD+NOH or PAF (PD+NOH/PAF group, N=13). We compared the results to those in patients with multiple system atrophy, which usually entails NOH with normal cardiac sympathetic innervation (MSA, N=15), and in normal control subjects (N=5). RESULTS: The innervated and denervated groups did not differ in baseline mean pre-ejection period index or systolic time ratio index. Tyramine increased cardiac contractility in the MSA patients and controls but not in the PD+NOH/PAF group. For similar heart rate responses, the PD+NOH/PAF group required less isoproterenol (p<0.01) and had lower plasma isoproterenol levels (p<0.01) than did the MSA group. CONCLUSIONS: Among patients with NOH those with cardiac sympathetic denervation have an impaired inotropic response to tyramine and exaggerated responses to isoproterenol. This pattern suggests that cardiac denervation is associated with decreased ability to release endogenous norepinephrine from sympathetic nerves and with supersensitivity of cardiac beta-adrenoreceptors. SN - 1353-8020 UR - https://www.unboundmedicine.com/medline/citation/18514012/Functional_effects_of_cardiac_sympathetic_denervation_in_neurogenic_orthostatic_hypotension_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S1353-8020(08)00114-4 DB - PRIME DP - Unbound Medicine ER -