Self-diagnosis of orthostatic hypotension in a patient with autonomic failure

M.C. Boer, N. van Dijk, W. Wieling
Department of Medicine, Academic Medical Centre. University of Amsterdam, Amsterdam (The Netherlands)

The patient is a 56-year old teacher, who has experienced spells of “dizziness” (lightheadedness), visual black-outs and periods of syncope for twenty years. In twelve years’ time he has been examined by 11 different medical specialists. After being diagnosed as having a ‘burn-out’, he was declared unfit for work. A low standing blood pressure was identified on one occasion, but this finding has never been explored any further[1].

Over the years his symptoms aggravated. They occurred on changing from a supine or sitting to a standing position, after the transition from moderate to strenuous physical exercise and after straining. During these provocations he experienced blurring of vision and sometimes visual black-out, aching pain in his neck- and shoulder muscles and sometimes loss of consciousness.

Since 3-4 years he has had complaints of erectile dysfunction and loss of perspiration. There were no urinary tract complaints. The orthostatic symptoms aggravated on warm days and resolved on sitting down, squatting or bending over. He discovered that his symptoms also decreased by placing one leg on a chair during prolonged standing [see case 6 in this section]. Despite these impediments he led an active life; he played badminton, though he needed to squat (see case 7 in this section) every three hits to prevent syncope from occurring.

Figure 1. Finger arterial pressure and heart rate changes before (left panel) and after (right panel) extracellular fluid volume expansion.

For the patient and his relatives these symptoms were hard to understand, especially since the patient was perfectly healthy in every other aspect. He believed that his complaints could be related to a low upright blood pressure and therefore performed an internet search for ‘hypotension’. He ended up at the site of John Hopkins University (www.jhu.edu). On this site he found, among others, the name of our group and contacted us by e-mail.

Orthostatic hypotension was obvious during cardiovascular reflex testing. Finger blood pressure was 125 / 60 mmHg in supine position and dropped within one minute to 45 / 30 mmHg after standing, forcing the patient to sit down. On standing heart rate increased from 58 to 80 per minute.

Plasma levels of noradrenaline, adrenaline and dopamine were low and did not increase on standing. Medical history, cardiovascular reflex testing and lab results are characteristic for ‘pure autonomic failure’, a condition of unknown origin with postganglionic deficits of the autonomic nervous system[2].

The patient received extensive information and explanation of his condition; he was advised to apply the manoeuvres he had discovered to improve orthostatic tolerance (see case 7 in this section), to increase his daily fluid intake (above 2 L / day), to utilise amply dietary salt (10 g / day) and to sleep in head-up position[3]. In addition the patient received a prescription for fludrocortison 0,1 mg / day. As a result of these measures the patient’s orthostatic complaints have diminished considerably. On repeated cardiovascular testing finger blood pressure dropped from 120 / 55 mmHg to “only” 60 / 40 mmHg 1 minute after standing up (Fig. 1).

Editor's comments

Orthostatic faints are most readily identified by a careful medical history in which the association with posture is documented (i.e. syncope occurring shortly after changing from a lying or sitting to a standing position or prolonged orthostatic stress). It is of particular importance for patients to identify reversible causes of orthostatic hypotension like volume depletion and the effect of medication[2][3]. The drugs most frequently associated with orthostatic syncope are vasodilators and diuretics[4]. Alcohol can also be associated with orthostatic syncope, by causing orthostatic intolerance (vasodilation and volume depletion) as well as inducing autonomic and somatic neuropathy. Elimination of the responsible drug or offending agent usually is enough to improve symptoms.

In a small minority of cases orthostatic hypotension is caused by impairment of autonomic reflexes required for maintaining blood pressure in the upright position[5]. This disorder is called autonomic failure[2]. Autonomic failure can be due to a primary disease (pure autonomic failure, multiple system atrophy), secondary to other diseases (diabetes, amyloidosis) affecting the autonomic nervous system or due to drugs[2]. Orthostatic hypotension due to primary autonomic failure typically occurs in older male adults. Almost without exception, they have a history of erectile and urinary tract dysfunction[2][3].

With a significant and persistent decrease in arterial pressure characteristic features occur. Symptoms include lightheadedness and blurring of vision. A neck ache radiating to the occipital region of the skull and to the shoulders (coat hanger distribution) often precedes actual loss of consciousness. The postulated mechanism of this virtually unique symptom of postural hypotension is ischemia in continuously contracting postural muscles. Other symptoms suggesting impaired perfusion of muscle tissue are lower back and buttock ache or angina pectoris. Typically symptoms develop in minutes on standing or walking and resolve on lying down [2][6]. Patients with autonomic failure quickly learn to use these symptoms as a warning signal that they must lie down to restore an adequate perfusion pressure. If the patient remains upright a gradual fading of consciousness occurs and the patient slowly falls to his knees. Sudden postural attacks and true syncope may, however, also occur. Symptoms and signs of autonomic activation like sweating or a vagally induced bradycardia are absent in patients with autonomic failure. Orthostatic syncope can be diagnosed when there is documentation of orthostatic hypotension associated with syncope or presyncope. Carefully measuring blood pressure with a sphygmomanometer supine and after standing suffices for the routine assessment of orthostatic blood pressure control in the office or at the bedside. For the diagnosis of orthostatic hypotension, arterial blood pressure must be measured when the patient adopts the standing position after 5 minutes in supine position. Orthostatic hypotension is defined as a decline in blood pressure of at least 20 mmHg systolic and / or 10 mmHg diastolic within 3 minutes of standing, regardless whether or not symptoms occur[2]. If the patient does not tolerate standing for this period, the lowest systolic blood pressure during the upright position should be recorded. Measurements should be continued after 3 minutes of standing if blood pressure is still falling at 3 minutes. In some patients with syncope and a history suggestive of impaired orthostatic blood pressure control blood pressure measurements in upright position may be normal. In these patients additional tests, using provocative stimuli as food ingestion and exercise, may be needed to unmask orthostatic hypotension. A useful alternative is a 24 hour or longer ambulatory blood pressure recording under daily circumstances, similar to those associated with symptoms in the individual patient.

References

1. Parts of this case were published earlier: Van Dijk N, Harms MPM, Wieling W. Three patients with unrecognized orthostatic intolerance. Ned Tijdschr Geneesk. 2000;144:249-54. We thank the Nederlands Tijdschrift voor Geneeskunde for permitting this reproduction.

2. Bannister R, Mathias CJ. Management of postural hypotension. In: Mathias CJ, Bannister R. Autonomic Failure. A Textbook of clinical Disorders of the Autonomic Nervous system. Oxford, Oxford University Press 1999 pp 342-356

3. Wieling W, Cortelli P, Mathias CJ. Treating neurogenic orthostatic hypotension. In: The Autonomic Nervous System, Part II. Dysfunctions. Handbook of Clinical Neurology Vol 75 (31), O Appenzeller (Ed). 2000 pp: 713-729

4. Hanlon JT, Linzer M, MacMillan JP, Lewis IK, and Felder AA. Syncope and presyncope associated with probable adverse drug reactions. Arch Intern Med. 1990 Nov;150(11):2309-12.
5. Smit AA, Halliwill JR, Low PA, and Wieling W. Pathophysiological basis of orthostatic hypotension in autonomic failure. J Physiol. 1999 Aug 15;519 Pt 1(Pt 1):1-10. DOI:10.1111/j.1469-7793.1999.0001o.x |
6. Bleasdale-Barr KM and Mathias CJ. Neck and other muscle pains in autonomic failure: their association with orthostatic hypotension. J R Soc Med. 1998 Jul;91(7):355-9. DOI:10.1177/014107689809100704 |