Case histories - Orthostatic hypotension

Orthostatic hypotension and autonomic neuropathy

History

A 60 year old gentleman presents to you with a 1 month history of dizziness when standing. He has also previously experienced 2 episodes of witnessed syncope lasting between 15 and 30 seconds with rapid recovery. There was no associated tongue biting, incontinence or limb jerking. He reports constipation, dry eyes and a dry mouth. He has no significant past medical history and is not taking any regular medications.

Examination

Cardiovascular examination is normal, and his lying blood pressure is 128/64 dropping to 84/44 on standing.

Which investigations should be performed in primary care?

Blood tests including U+E, FBC and random cortisol are useful in investigating orthostatic hypotension. An ECG performed in the surgery is normal.

What would you do next?

These features suggest orthostatic hypotension. You advise him of lifestyle measures to prevent postural hypotension including increased fluids, compression garments, postural counterpressure manouevres and sleeping with the head end of his bed raised. His symptoms continue and you prescribe fludrocortisone. You review him 4 weeks, but he reports no improvement in his symptoms, so you refer him to the local syncope clinic for further assessment.

Outcome

He undergoes autonomic testing which confirms autonomic dysfunction and after further assessment by a neurologist, he is diagnosed with an autoimmune autonomic neuropathy. He is treated with a combination of fludrocortisone and midodrine, and his symptoms improve.

Learning Points

Most causes of orthostatic hypotension are due to side effects of medication or intravascular volume depletion; however, a small proportion are due to impairment of autonomic reflexes.
Autonomic failure may be due to a primary cause (pure autonomic failure, multiple system atrophy, Parkinson's Disease) or secondary to other diseases (e.g. diabetes, amyloidosis).
Consider these rarer causes if there are no obvious culprit drugs and a lack of response to treatments in primary care.

Orthostatic hypotension after squatting case history

History

A 32 year old lady presents to her GP after experiencing an episode of syncope whilst exercising. She has recently started an aerobics class and after squatting then standing, she reports having felt light headed. She developed loss of consciousness for approximately 15 seconds and was not confused on recovery. The episode was witnessed by the other members of her class. She has no significant medical history and does not take any regular medications.

Examination

Cardiovascular examination is normal, with no postural difference in blood pressures.

Which investigations should be performed in primary care?

An ECG should be performed and this is normal.

What happened next?

Due to the association of syncope with exercise, the GP refers her to a cardiologist. for further assessment.

Outcome

The cardiologist monitors her blood pressure and heart rate with beat to beat monitoring whilst squatting and standing and her blood pressure is noted to drop when she stands up from squatting and she again reports feeling dizzy. She is diagnosed with initial or immediate orthostatic hypotension and advised to use physical counter-manoeuvres by tensing the muscles in her legs when standing from sitting or lying with no further syncopal episodes.

Learning points

A detailed history is key when assessing syncope to determine triggers which may provide a clue to the underlying diagnosis.
Standing from squatting may lead to a significant fall in blood pressure that can precipitate syncope due to sudden reduction of venous return.
Physical counter-manoeuvres can counteract this effect by antagonising the blood pressure fall and increasing venous return from muscles. They are easily taught to patients.