Autonomic failure is a condition that develops when the nerves that control the heart and circulation become damaged. It is most often found in adults with neurodegenerative diseases that affect the brainstem or peripheral nerves, like Parkinson disease, Lewy body dementia, and multiple system atrophy. As a result, these patients have problems with blood pressure control, which is why they are followed in autonomic clinics.
One of the most challenging aspects for any doctor encountering a patient with autonomic failure is how to manage their blood pressure. When a patient with Parkinsonism stands up, their blood pressure can plummet to very low levels. But, when they lie down it often enters the hypertensive range. Treating the lows, often worsens the highs, – and vice versa, which means you have to be vigilant about both. More recently, there has been a shift in the attention to high blood pressure in Parkinson’s and multiple system atrophy. We recently took part in writing new international guidelines for the diagnosis and management of supine hypertension. But until now, it wasn’t quite clear what were the consequences of high blood pressure in patients with autonomic failure on the organs.
In the general population, high blood pressure (hypertension) is known as the silent killer and accelerates hardening of the arteries (arteriosclerosis). This can lead to stroke, coronary thrombosis and kidney failure. Blood pumped from the heart flows through increasingly narrowing arteries and arterioles, into the capillaries which have the smallest diameter. The capillaries have very delicate walls, which allows the oxygen and nutrients to diffuse across the membranes and into the tissues, but means they are very fragile. If the arterial pressure builds up, it’s the job of the small muscular arterioles to constrict and hold back the blood flow to prevent the pressure from the capillaries from rising and the vessels from bursting. Overtime, this causes the heart muscle to become thicker (hypertrophic) in order for the heart to pump harder against the resistance. It also destroys the white matter insulating the nerve cells in the brain and damages the kidney.
A new study led by Dr. Alberto Palma has led to some important new insights. Over many years, the team followed kidney function, thickness of the heart muscle, and the intensity of white matter lesion in a total of 57 patients with autonomic failure – the vast majority of which had multiple system atrophy. They divided the patients into those with and without high blood pressure and assessed their organ function over 2-years. Not only was high blood pressure when lying down associated with a higher incidence of organ damage to the heart, kidney and brain, it was also found to have a higher all-cause mortality. It’s something we have long suspected, but now can prove.
For the autonomic specialists, this raises some very important questions. The next steps are to define ways to prevent or manage high blood pressure in patients with autonomic failure. The paper underscores the importance of measuring blood pressure in different positions. In addition to taking readings while the patient is sitting, it’s also important to take measures lying flat and standing up. It’s really this range of blood pressures that can help guide treatment. It’s important to make sure we are detecting and managing supine hypertension as this has clear consequences for the organs.
Read more here:
Learn more about how to measure your blood pressure at home: here
Learn the non-pharmacological remedies that can help lower supine blood pressure in patients with autonomic failure: here.