CARDIOVASCULAR DYSAUTONOMIA IN OLDER ADULTS – ETIOLOGY, DIAGNOSIS, AND HEALTH–RELATED CONSEQUENCES

Project: Dissertation

Description

The hemodynamic homeostasis requires normal function of the cardiovascular, endocrine, and autonomic nervous systems. In cardiovascular dysautonomic states, the circulatory redistribution may lead to hypotension, thus compromising cerebral blood flow with symptoms such as blurred vision, fatigue, dizziness, and, in the most extreme cases, syncope. In classical reflex syncope, cardiovascular reflexes become transiently inappropriate while in orthostatic hypotension (OH) sympathetic efferent activity may be chronically impaired. OH is a major manifestation of autonomic failure, and is a frequent finding in the older adults, with prevalence between 10 and 35%. The prevalence of OH increases with age and comorbidities, such as neurodegenerative, cardiovascular, metabolic and renal diseases. The presence of OH is associated with a significantly increased mortality and cardiovascular disease incidence. However, older adults who suffer unexplained syncope, presyncope or present with signs of chronic cardiovascular dysautonomia, OH and/or reflex syncope are often omitted in epidemiological and interventional studies.
The role of molecular biomarkers in the diagnosis of cardiovascular dysautonomia, OH and syncope is still debatable. Several plasma proteins, signal substances and neurohormones have been studied for their diagnostic utility in syncopal syndromes but more studies are required. The purinergic signaling system, including adenosine and adenosine triphosphate (ATP), has been recently proposed in the assessment of unexplained syncope without prodrome. According to previous studies, low plasma–adenosine level predisposes to paroxysmal AV–block and carotid sinus syndrome, whereas a high level of plasma–adenosine predisposes to hypotensive tendency and recurrent vasovagal syncope. In parallel, the adenosine/ATP provocation test has been performed to demonstrate adenosine hypersensitivity and paroxysmal cardioinhibitory propensity for selection of appropriate pacemaker candidates.

Layman's description

The hemodynamic homeostasis requires normal function of the cardiovascular, endocrine, and autonomic nervous systems. In cardiovascular dysautonomic states, the circulatory redistribution may lead to hypotension, thus compromising cerebral blood flow with symptoms such as blurred vision, fatigue, dizziness, and, in the most extreme cases, syncope. In classical reflex syncope, cardiovascular reflexes become transiently inappropriate while in orthostatic hypotension (OH) sympathetic efferent activity may be chronically impaired. OH is a major manifestation of autonomic failure, and is a frequent finding in the older adults, with prevalence between 10 and 35%. The prevalence of OH increases with age and comorbidities, such as neurodegenerative, cardiovascular, metabolic and renal diseases. The presence of OH is associated with a significantly increased mortality and cardiovascular disease incidence. However, older adults who suffer unexplained syncope, presyncope or present with signs of chronic cardiovascular dysautonomia, OH and/or reflex syncope are often omitted in epidemiological and interventional studies.
The role of molecular biomarkers in the diagnosis of cardiovascular dysautonomia, OH and syncope is still debatable. Several plasma proteins, signal substances and neurohormones have been studied for their diagnostic utility in syncopal syndromes but more studies are required. The purinergic signaling system, including adenosine and adenosine triphosphate (ATP), has been recently proposed in the assessment of unexplained syncope without prodrome. According to previous studies, low plasma–adenosine level predisposes to paroxysmal AV–block and carotid sinus syndrome, whereas a high level of plasma–adenosine predisposes to hypotensive tendency and recurrent vasovagal syncope. In parallel, the adenosine/ATP provocation test has been performed to demonstrate adenosine hypersensitivity and paroxysmal cardioinhibitory propensity for selection of appropriate pacemaker candidates.
StatusActive
Effective start/end date2016/02/01 → …

Participants