Challenges in the Older Patient
Frailty
As people are living longer, frailty and pre-frailty are more commonly encountered in clinical practice. Frailty is a reduction in the ability to respond to stressors and an increased vulnerability to adverse outcomes.103 There is no consensus on how best to operationalise or define frailty but two types of definitions have emerged as the most commonly used constructs: the Cumulative Burden Index as proposed where frailty is defined as an accumulation of health conditions and deficits, and the ‘Biological Syndrome Model’ as proposed by Fried:103 a person is deemed to be frail if they present with three or more of: poor grip strength, slow walking speed, low levels of physical activity, exhaustion and unintentional weight loss. Frailty is a predictor of falls, hospitalisation, disability and death.103
Unwitnessed Events in the Older Person
In the older adult a witness account may not be available for falls or syncopal events in up to 40 % of patients.16
Medications, Polypharmacy and Syncope
Polypharmacy is more common with advancing age. Some of the most frequently prescribed syncope-related medications used in combination are anti-hypertensives, anti-anginals, anti-histamines, anti-psychotics, tricyclic anti-depressants and diuretics. These cause bradycardia, QT interval prolongation, OH and VVS. Drug interactions can also cause syncope particularly in the older patient with multi-morbidity and polypharmacy.104 A temporal association between onset or change of medication and symptoms may be evident although progression of age-related physiological changes may cause syncope even with longstanding established medication use.24
TILDA reported an increased risk and frequency of syncope with use of tricyclic anti-depressants.105 The side effect most frequently reported is hypotension, but bradycardia and tachycardia have also been reported.106,107
Cognition
Cognitive impairment rises with age: 20 % of people over 80 years have established dementia,108 rising to 40 % over 90 years.109 Cognitive impairment is characterised by memory problems, attention difficulties and executive dysfunction – hence compliance with cardiac monitoring systems may be compromised.
Cognitive impairment is particularly high in older patients with CSH.55 Likewise, patients with some subtypes of dementia such as Lewy Body dementia55 and Alzheimer’s dementia have a higher prevalence of syncope, OH and CSH.108 Establishing a causal relationship between symptoms and arrhythmia or hypotension is particularly difficult in these patients given that the history is not reliable and events are often unwitnessed.3,6,110
There is emerging evidence that low BP may cause or exaggerate cognitive dysfunction,111 possibly because cerebral hypoperfusion is associated with cerebral damage via small vessel arteriosclerosis and cerebral amyloid angiopathy, as well as exaggerated white matter disease.112
Dual Diagnosis
In the older patient multiple causes of syncope may be present including cardiac (bradyarrhythmia, SVT tachyarrhythmias, ventricular tachyarrhythmias, long QT) and reflex syncope or autonomic impairment Table 3.22 Attribution of cause in the context of multiple abnormalities is not always possible, and treatment of all possible causes is recommended.
In one series of patients with syncope, mean age 66.5 years ± 18 years; 23 % had a dual diagnosis. The principal predictors of dual diagnosis were advanced age, treatment with alpha-receptor blockers and benzodiazepines. The most frequent dual diagnoses were OH and VVS: 2.8 % had a triple diagnosis, and these were the oldest old.28
Focal Neurology with Syncope
Transient ischaemic attacks or stroke and syncope are considered mutually exclusive presentations. However, one recent series reported that 5.7 % of syncope patients experienced focal neurological events at the time of syncope or pre-syncope. Awareness of this phenomenon is important to prevent misdiagnosis of stroke and inappropriate increase of anti-hypertensive medications, which would further exacerbate hypotensive symptoms.113,114