Predictors of inotropic and chronotropic effects of NG-monomethyl-L-arginine.
Eur J Clin Invest
; 39(4): 273-9, 2009 Apr.
Article
em En
| MEDLINE
| ID: mdl-19292882
ABSTRACT
BACKGROUND:
The haemodynamic effects of intravenous infusion of the non-selective nitric oxide synthase (NOS) L-omega monomethyl arginine (L-NMMA) have previously been characterized in humans. Its effect of reducing cardiac index (CI) is an important reason for the increase in mortality in patients with septic shock receiving L-NMMA in a pivotal outcome trial for this indication. The mechanism for the reduction in CI however, is uncertain.METHODS:
In this study, we investigated the haemodynamic and arterial stiffness response to a bolus intravenous infusion of L-NMMA (3 mg kg(-1) over 5 min) in 26 healthy human volunteers to clarify the likely cause of L-NMMA induced negative inotropic and chronotropic effects. Digital photoplethysmography (MicroMedical Pulse Trace) was used to derive two measures of arterial stiffness stiffness index, a measure of large arterial stiffness, and reflection index (RI), a measure of small- to medium-sized arterial stiffness. Haemodynamic measurements of systolic blood pressure, diastolic blood pressure, heart rate, systemic vascular resistance index (SVRI), stroke index and CI were made using a bioimpedance monitor (BioZ Cardiodynamics).RESULTS:
We found that changes in CI during L-NMMA are closely related to changes in RI and SVRI.CONCLUSION:
The negative inotropic effect of L-NMMA may be a result of an increase in coronary vascular resistance and a resultant decrease in myocardial perfusion. The reduction in CI may also result from a direct reduction of the normal positive inotropic effect of NO by L-NMMA which is closely correlated with its effects on SVRI.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Artérias
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ômega-N-Metilarginina
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Inibidores Enzimáticos
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Frequência Cardíaca
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Hemodinâmica
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Contração Miocárdica
Tipo de estudo:
Diagnostic_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Adult
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Female
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Humans
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Male
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article