Background: Sympathetic activation occurs in hypertension (HT) and after acute myocardial infarction (AMI) and is related to greater cardiovascular risk. Also, AMI in patients with HT (AMI-HT) carries greater risk than that in normal subjects (AMI-NT). We therefore planned to determine whether the sympathetic activation and its duration after AMI are greater in patients with antecedent HT than in patients with normal arterial pressure (NT).
Methods: In 68 matched subjects with uncomplicated AMI-HT (n = 17), AMI-NT (n = 17), HT (n = 17), and NT (n = 17), we measured resting muscle sympathetic nerve activity (MSNA) as the mean frequency of multiunit bursts (m-MSNA) and single units (s-MSNA). In AMI groups data were obtained 2 to 4 days after AMI and then at 3-month intervals until MSNA returned to levels found in HT and NT.
Results: The AMI-HT had greater (at least P < 0.05; ANOVA) s-MSNA (99 +/- 3.5 impulses/100 cardiac beats) than AMI-NT (84 +/- 2.8 impulses/100 cardiac beats). During follow up, s-MSNA hyperactivity in AMI-HT was always greater than in AMI-NT, and returned to values found in HT and NT (84 +/- 3.5 impulses/100 cardiac beats and 62 +/- 4.4 impulses/100 cardiac beats, respectively) 9 months after AMI. Similar results were obtained for m-MSNA.
Conclusions: AMI in hypertensives resulted in greater MSNA levels lasting at least 6 months longer than AMI in normotensives. This indicates that AMI further augmented the MSNA hyperactivity of HT and that this could be one mechanism involved in the reported worse prognosis in AMI-HT.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.amjhyper.2006.03.015 | DOI Listing |
J Hypertens
November 2011
Department of Cardiology, Leeds Teaching Hospitals NHS Trust, University of Leeds, Leeds, UK.
Objectives: Hypertension and its subsequent cardiovascular complications have been associated with sympathetic neural activation, and their prevalence in women increases after the menopause. However, there have been no data on the level of sympathetic activation and its relationship to vascular blood flow following the menopause. Therefore, we planned to find out whether the behavior of muscle sympathetic nerve activity (MSNA) and calf blood flow (CBF) in women with and without essential hypertension (EHT) is changed following the menopause.
View Article and Find Full Text PDFJ Hum Hypertens
March 2007
The Department of Cardiology, St James's University Hospital, Leeds, UK.
We planned to determine whether or not there is a difference in the level of muscle sympathetic nerve activity (MSNA) between hypertensive women and hypertensive men. Sympathetic activation of essential hypertension (EHT) has been associated with increased cardiovascular events, which are known to be less likely to occur in women than in men. Normal women have been reported to have less sympathetic nerve activity than men, but no reported data are available regarding gender differences in sympathetic activity in hypertensive subjects.
View Article and Find Full Text PDFClin Sci (Lond)
June 2007
The Department of Cardiology, St James's University Hospital, Beckett Street, Leeds LS9 7TF, UK.
The risk of cardiovascular disease has been linked to sympathetic activation and its incidence is known to be lower in women than in men. However, the effect of gender on the sympathetic vasoconstrictor drive has not yet been established. In the present study, we investigated whether there is a gender difference in MSNA (muscle sympathetic nerve activity) and blood flow, and to determine the mechanisms involved.
View Article and Find Full Text PDFAm J Hypertens
October 2006
The Department of Cardiology, St James's University Hospital, Leeds, UK.
Background: Sympathetic activation occurs in hypertension (HT) and after acute myocardial infarction (AMI) and is related to greater cardiovascular risk. Also, AMI in patients with HT (AMI-HT) carries greater risk than that in normal subjects (AMI-NT). We therefore planned to determine whether the sympathetic activation and its duration after AMI are greater in patients with antecedent HT than in patients with normal arterial pressure (NT).
View Article and Find Full Text PDFDiabetologia
November 2006
Department of Cardiology, St. James's University Hospital, Beckett Street, Leeds LS9 7TF, UK.
Aims/hypothesis: Type 2 diabetes mellitus with hyperinsulinaemia is a state of sympathetic nerve hyperactivity, which can develop subsequently in non-diabetic first-degree offspring of patients with type 2 diabetes. Although both type 2 diabetes and sympathetic activation are major cardiovascular risk factors, the level of sympathetic nerve activity is as yet unknown in offspring of type 2 diabetic patients who are ostensibly normal. We therefore sought to quantify sympathetic nerve activity and its relationship to plasma insulin levels in ostensibly normal offspring of patients with type 2 diabetes, relative to a matched normal control group with no family history of type 2 diabetes.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!