Parkinson's disease is one of the most common neurodegenerative diseases and causes a lot of issues in terms of quality of life, morbidity, and survival. According to Dr Ajit Menon, Senior Interventional Cardiologist at Sir HN Reliance Foundation Hospital, certain medicines used to treat Parkinson's, such as levodopa and certain anticholinergic agents, are also responsible for certain cardiovascular adverse reactions.
The most common cardiovascular involvement in patients with Parkinson's is autonomic nervous system dysregulation. This is usually manifested by something called orthostatic or postprandial hypotension, which means that during a change of position, the patient can experience a sudden fall in blood pressure, especially when standing up from a lying down position or from a sitting position, and can also experience a fall in blood pressure after meals. The patient can develop a sudden fall in blood pressure. This is because the normal regulation of blood pressure, which occurs during changes in position, is dysfunctional in patients with Parkinson's disease.
Moreover, these patients can also have an increased thickness of the heart muscle, which causes what is called diastolic dysfunction, when the ability of the heart to relax becomes impaired, thereby leading to breathlessness in these patients. Certain medicines used for Parkinson's can also worsen orthostatic hypertension and cause a fall in blood pressure on changes of position.
Certain medicines used in the treatment of Parkinson's can also cause ventricular arrhythmias, where the heart starts beating irregularly and at a very fast rate, which can be reversible once the treatment is stopped.
Another issue that occurs in patients with Parkinson's is that those with high blood pressure do not experience a dip in blood pressure at night, which is what normally happens in most patients and normal individuals. When blood pressure does not dip at night, it worsens the side effects of hypertension and can prolong the complications arising from high blood pressure. Parkinson's disease is also characterised by a high degree of inflammation in the vessels. It causes insulin resistance, is associated with an altered cholesterol or lipid profile, and something called oxidative stress.
All of these factors together can cause ischemic heart disease or blockages in the arteries supplying the heart muscle. It can also lead to cardiomyopathies, arrhythmias, and in some cases, sudden cardiac death, although this incidence has not been definitively correlated.
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