Patterns of orthostatic hypotension and the evaluation of syncope

Nearly half of us experience a loss of consciousness at some point in our lives. However, passing out is still a powerful event for all involved. Whilst fainting is common, sometimes there are serious underlying causes.

For this thesis, investigations were done into the evaluation and treatment of patients who were referred to the emergency department after losing consciousness due to a large fall in blood pressure (syncope). When you lose consciousness this way, it can be divided into Vasovagal Syncope (fainting), Orthostatic Hypotension (blood pressure drop after standing up), and Cardiac Syncope (for example a heart rhythm disorder).

In order to detect Orthostatic Hypotension, blood pressure needs to be measured in both lying and standing positions. For this, we used a continuous non-invasive finger blood pressure measure. Three abnormal blood pressure recovery patterns have been defined, in addition to the normal pattern whereby blood pressure drops after standing up but recovers to normal levels within 30 seconds.

The first pattern, Initial Orthostatic Hypotension, is frequent among young adults. This is a deep blood pressure drop directly after standing up, with a quick recovery. In older adults, a Delayed Blood Pressure Recovery Pattern and Classic Orthostatic Hypotension is more frequent. In a Delayed Blood Pressure Recovery Pattern, for example caused by medication, older patients can become dizzy, fall, or lose consciousness shortly after standing up. Moreover, the Delayed Pattern is associated with depression and cognitive disorders.

This investigation also shows that a standardised evaluation at the emergency department leads to more correct diagnoses, and that referral to the syncope is beneficial to younger patients with frequent syncope. This results in less syncope and a better quality of life.