Syncope In Older People
Investigating and managing older people in any clinical situation requires an understanding of their special circumstances. Older people however represent a very heterogeneous group. Some age early, some have multiple diseases and some maintain great health into great old age. Therefore it is important to assess each one individually.
In managing syncope in older people, there are changes in the cardiovascular, renal and autonomic nervous systems which play an important role.
As body systems deteriorate with age, compensatory mechanisms are employed to maintain homeostasis at rest. So when an additional demand is made on the system eg during standing, hot weather or illness, there is less reserve remaining to respond to that demand. Also the compensatory mechanisms often act more slowly and may only reach lower peak levels. Therefore the response may be too slow or insufficient.
Older people’s systems are affected by 3 major influences:
- age-related changes (such as a slower, reduced response to standing),
- the consequences of diseases (such as ischaemic heart disease or autonomic dysfunction)
- medication - both individual and interactions between drugs.
Collapse ? cause: fall or blackout?
It is common for older people to present with a ‘collapse’, which may have been either a fall or a blackout (with loss of consciousness). Many old people spend a lot of time alone, so a collapse is often unwitnessed and there is no observer to provide additional information. Also, older people may not remember events immediately preceding their collapse, including prodromal symptoms which would provide additional clues. This is probably related to amnesia caused by cerebral hypoperfusion, as systemic blood pressure falls. If the person has dementia or a delirium, this will also make the history unclear. In addition, if an older person is unsteady, they are more likely to lose their balance and fall if their blood pressure drops. So a small drop in blood pressure may cause a fall even if the blood pressure drop is not sufficiently large enough to cause loss of consciousness.
Therefore, unless there is a clear history of a trip, slip or an expected loss of balance, a fall or collapse in an older person should be investigated as syncope.
Determining the cause of syncope in the older person requires an understanding of the changes in physiology that occur with aging and an understading of the conditions more likely to occur in an older person.
The following pages detail the age related changes that presipose the elderly to syncope and detail the common causes of syncope in the elderly and an approach to investigation and priciples of management. In summary however when assesing and manageing older people with syncope it is important to be aware that:
- When older people are dehydrated, they feel less thirsty and cannot concentrate their urine as much, so they need to ensure they drink sufficient fluid, especially with hot weather, fever or diarrhoea.
- Older people do not concentrate their urine overnight as well, so they will be more prone to dehydration by morning
- Older people are more sensitive to volume changes than younger people. Their blood vessels are less compliant, so a decreased plasma volume eg dehydration, causes a decreased perfusion pressure. Therefore older people need to ensure they are well hydrated at all times.
- Older people have poorer cerebral autoregulation, so a drop in the systemic blood pressure is not as easily compensated for. Older people are therefore more likely to have symptoms due to cerebral hypoperfusion.
- Older people are more likely to have amnesia for a collapse due to cerebral hypoperfusion. They may also be confused due to dementia or a delirium.
- In older people, compensatory responses tend to be slower and reach a lower maximum response than in younger people eg on standing up.
- Age Related Changes That Predispose To Syncope
- Common Causes of Syncope in Older People
- Multifactorial Syncope in Older People
- Assessing the Older Person With Syncope
