The role of cardiac autonomic function in hypertension and cardiovascular disease

Area of Science:

• Cardiovascular Physiology
• Autonomic Neuroscience
• Hypertension Research

Background:

• Hypertension is frequently associated with autonomic nervous system (ANS) abnormalities.
• Clinically, this manifests as hyperkinetic circulation with elevated heart rate, blood pressure, plasma norepinephrine, and cardiac output.
• Increased sympathetic nervous system (SNS) activity is a hallmark, observed in early, borderline, and established hypertension.

Purpose of the Study:

• To review the evidence for ANS abnormalities in hypertension.
• To describe the transition from a hyperkinetic circulatory state to established hypertension.
• To explore the association between ANS dysfunction and pressure-unrelated cardiovascular risk factors.

Main Methods:

• Review of existing literature on autonomic nervous system function in hypertension.
• Analysis of studies using spectral analysis of heart rate variability.
• Inclusion of microneurographic assessments of muscle sympathetic nerve activity.
• Examination of longitudinal studies documenting hemodynamic changes over time.

Main Results:

• Elevated sympathetic activity and norepinephrine release are consistently found in hypertensive individuals.
• A transition from hyperkinetic circulation to high-resistance hypertension occurs, involving vascular hypertrophy and decreased cardiac output.
• ANS abnormalities are linked to cardiovascular risk factors like obesity and insulin resistance.

Conclusions:

• Autonomic nervous system dysfunction is a key feature of hypertension, contributing to its development and progression.
• The sympathetic nervous system plays a crucial role in the hemodynamic changes observed in hypertension.
• Understanding these associations may inform strategies for managing hypertension and associated cardiovascular risks.