Related Experiment Video
Updated: Jul 17, 2026
07:54
Long-term Blood Pressure Measurement in Freely Moving Mice Using Telemetry
Published on: May 17, 2016
Single-unit sympathetic discharge : quantitative assessment in human hypertensive disease
J P Greenwood1, J B Stoker, D A Mary
1Department of Cardiology, The University of Leeds (UK). john_greenwood@hotmail.com
Circulation
|September 24, 1999
Summary
Sympathetic nerve activity is elevated in hypertension. Measuring single vasoconstrictor units (s-MSNA) reveals increased sympathetic output in early hypertension compared to severe stages.
Area of Science:
- Cardiovascular Physiology
- Neuroscience
- Hypertension Research
Background:
- Inconsistent reports exist regarding sympathetic hyperactivity in hypertension using microneurography.
- Previous studies relied on multiunit discharges (MSNA bursts), potentially obscuring finer details of sympathetic output.
- Investigating single vasoconstrictor units (s-MSNA) offers a more precise method to assess sympathetic activity.
Purpose of the Study:
- To characterize sympathetic output in hypertensive disease by analyzing single vasoconstrictor units (s-MSNA).
- To compare sympathetic activity measurements from single units versus multiunit bursts.
- To investigate differences in sympathetic activity across varying stages of essential hypertension.
Main Methods:
- Examined 74 subjects across a spectrum of blood pressure: normal (NT), high normal (HN), and essential hypertension stages 1-3 (EHT-1, EHT-2/3).
- Measured peripheral sympathetic activity using both multiunit bursts (MSNA) and single-unit vasoconstrictor impulses (s-MSNA).
- Correlated s-MSNA and MSNA findings and analyzed variability.
Main Results:
- A significant correlation was observed between s-MSNA and MSNA measurements.
- Both EHT-1/2/3 and HN groups exhibited significantly greater s-MSNA and MSNA than the NT group (P<0.01 and P<0.05, respectively).
- s-MSNA revealed significantly higher sympathetic output in EHT-1 compared to EHT-2/3 (P<0.05), a difference not apparent with MSNA bursts.
Conclusions:
- Quantification of s-MSNA provides robust evidence of increased central sympathetic output in essential hypertension.
- This single-unit technique offers novel insights, demonstrating augmented sympathetic output in milder/earlier hypertension stages compared to more severe disease.
Related Concept Videos
01:30Blood Pressure
Blood pressure (BP) is the pressure or force of blood exerted on the artery's walls as it circulates through the body. It is essential for maintaining blood flow throughout the body.
The average BP in an adult is typically around 120/80 mmHg (millimeters of mercury). In this measurement, the numerator (120) indicates the systolic pressure, which is the pressure in the arteries during the contraction of the heart's ventricles as blood is expelled. The denominator (80) represents the diastolic...
The average BP in an adult is typically around 120/80 mmHg (millimeters of mercury). In this measurement, the numerator (120) indicates the systolic pressure, which is the pressure in the arteries during the contraction of the heart's ventricles as blood is expelled. The denominator (80) represents the diastolic...
01:15Assessment of blood pressure in brachial artery(one-step method)
This procedural guide systematically measures blood pressure using an oscillometric digital sphygmomanometer, emphasizing accuracy, patient safety, and comfort.
Prepare for the Procedure:
Prepare for the Procedure:
01:23Assessment of blood pressure in brachial artery(two-step method)
Measuring blood pressure is a fundamental skill in healthcare that aids in diagnosing and monitoring hypertension and other cardiovascular conditions. An aneroid sphygmomanometer, commonly used in clinical settings, offers a manual and precise method for blood pressure measurement. The technique for using this instrument involves specific steps that must be carefully executed to ensure accuracy. The following detailed description outlines a two-step technique for assessing blood pressure using...
01:28Special considerations while measuring blood pressure
When assessing blood pressure (BP), healthcare professionals must consider various factors and potential unexpected outcomes to ensure accurate readings and provide proper patient care. Adhering to these guidelines is essential to achieving the most reliable results.
Monitoring Both Arms:
Monitoring BP in both arms during the initial assessment is advisable, as the systolic value may differ by five to ten mm Hg between arms. For subsequent BP assessments, use the arm with the higher reading.
Monitoring Both Arms:
Monitoring BP in both arms during the initial assessment is advisable, as the systolic value may differ by five to ten mm Hg between arms. For subsequent BP assessments, use the arm with the higher reading.
01:24Blood Pressure
The movement of blood in a human body, commonly referred to as blood flow, is determined by the volume of blood that traverses a certain section of the bodily system per unit time. It is the rhythmic contraction of the heart's ventricles that primarily instigates this movement. As the ventricles contract, blood is forced into the prominent arteries, which then flow from areas of greater pressure to lower pressure areas. This movement continues into smaller arteries and arterioles and...
01:30Hypertension III: Clinical Manifestations and Diagnostic Studies
Hypertension is asymptomatic and also referred to as the "silent killer" until it progresses to a severe stage or causes target organ disease. Patients may experience symptoms stemming from the strain on blood vessels and tissues in various organs or the heart's increased workload.Physical exams might show no abnormalities other than high blood pressure. Signs of vascular damage, when present, correspond to the organs supplied by the affected vessels, leading to target organ damage. For...