Sympathetic Hyperactivity and Aortic Sympathetic Nerve Sprouting in Patients with Thoracic Aortic Dissection

BackgroundTo determine the yet unknown relation between thoracic aortic dissection (TAD) and sympathetic nervous system activity.MethodsVariables such as electrocardiography, blood pressure, respiratory activity, postganglionic muscle sympathetic nerve activity （MSNA）, plasma norepinephrine, tyrosine hydroxylase–positive nerve fiber density, and growth-associated protein 43–positive nerve fiber density were detected and statistically analyzed.ResultsTAD Patients showed a significant lower R-R interval variance and higher blood pressure, heart rate, respiratory rate, MSNA, plasma norepinephrine (reflecting elevated sympathetic nervous system [SNS] activity), higher tyrosine hydroxylase, growth-associated protein 43–positive nerve fiber density (reflecting sympathetic sprouting and innervation) than those of the control group.ConclusionsIn TAD patients, both overall and regional aortic SNS activities are elevated.