From the Research
Introduction to Cardiovascular and Multisystem Dysautonomia
Cardiovascular and multisystem dysautonomia refers to a group of disorders characterized by the malfunction of the autonomic nervous system (ANS), which regulates various involuntary functions of the body, including heart rate, blood pressure, and digestion. This condition can lead to a range of symptoms, from mild to severe, and can significantly impact an individual's quality of life.
Causes of Cardiovascular and Multisystem Dysautonomia
The causes of cardiovascular and multisystem dysautonomia can be primary or secondary, and central or peripheral 1. Primary dysautonomias are characterized by neurodegenerative diseases of unknown causes, such as pure autonomic failure, Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. Secondary dysautonomias, on the other hand, can be caused by various factors, including diabetes mellitus, which is the most common cause of autonomic neuropathy in developed countries 1. Other causes of secondary dysautonomia include cancer, such as lung, pancreatic, and testicular cancer, as well as certain autoimmune disorders.
Classification of Dysautonomia
Dysautonomia can be classified according to its etiology, as primary or secondary, or according to the deficient neurotransmitter, as cholinergic, adrenergic, or mixed (pan dysautonomia) 1. It can also be classified according to the anatomical distribution of the neurons that are affected, as central or peripheral.
Clinical Presentation
The clinical presentation of cardiovascular and multisystem dysautonomia can vary widely, depending on the underlying cause and the specific systems affected. Common symptoms include orthostatic hypotension, postural orthostatic tachycardia syndrome (POTS), chronic fatigue syndrome, and neurogenic orthostatic hypotension (nOH) 2. Other symptoms may include dizziness, weakness, pre-syncope, palpitations, and systemic symptoms such as nausea, vomiting, and abdominal pain.
Diagnosis
The diagnosis of cardiovascular and multisystem dysautonomia typically involves a combination of clinical evaluation, laboratory tests, and autonomic function tests. The gold standard methods for diagnosing cardiovascular autonomic neuropathy (CAN) include the Valsalva, Respiratory, and Orthostatic tests (30:15), which can be associated with RR Variability tests in the time domain and frequency domain to increase sensitivity 2.
Treatment
The treatment of cardiovascular and multisystem dysautonomia depends on the underlying cause and the severity of symptoms. In general, treatment is focused on managing symptoms and preventing complications. This may include:
- Medications such as fludrocortisone, midodrine, and droxidopa to manage orthostatic hypotension
- Lifestyle modifications, such as:
- Postural care
- Good hydration
- Higher salt intake
- Use of compression stockings and abdominal straps
- Portioned meals
- Supervised physical activity, mainly sitting, lying down, or exercising in water
- Avoiding triggers that can exacerbate symptoms, such as certain medications or activities
Caveats and Considerations
It is essential to note that the treatment of cardiovascular and multisystem dysautonomia can be complex and often requires specialized and multidisciplinary evaluation. There is no cure for most types of dysautonomia, and treatment is typically focused on managing symptoms and preventing complications. Additionally, the risk of exacerbation or triggering supine hypertension should be considered when treating patients with nOH 2.
Differential Diagnosis
The differential diagnosis of cardiovascular and multisystem dysautonomia includes a range of conditions that can cause similar symptoms, such as:
- Hypovolemia
- Medication-induced hypotension
- Cardiac conditions, such as heart failure or arrhythmias
- Neurological conditions, such as Parkinson's disease or multiple system atrophy
- Other autonomic disorders, such as POTS or chronic fatigue syndrome
Conclusion
Cardiovascular and multisystem dysautonomia is a complex and heterogeneous group of disorders that can cause significant morbidity and mortality. A thorough understanding of the causes, classification, clinical presentation, diagnosis, and treatment of these conditions is essential for healthcare providers to provide optimal care for patients with dysautonomia 3, 4, 5.