Neuroautonomic evaluation of patients with unexplained syncope: incidence of complex neurally mediated diagnoses in the elderly

[Syncope in older patients : Who needs what and when?]

The aim of diagnostic procedures in the context of syncope is the exclusion of cardiac diseases. Cardiac diseases as the cause of syncope have a high influence on the rate of mortality.

Tilt table test today - state of the art

A tilt table test (TTT) is an inexpensive, noninvasive tool for the differential diagnosis of syncope and orthostatic intolerance and has good diagnostic yield. The autonomic system malfunction which underlines the reflex syncope is manifested as either hypotension or bradycardia, while an orthostatic challenge is applied. The timing of the response to the orthostatic challenge, as well as the predominant component of the response help to differentiate between various forms of neurocardiogenic syncope, orthostatic hypotension and non-cardiovascular conditions (e.g., pseudosyncope). Medications, such as isoproterenol and nitrates, may increase TTT sensitivity. Sublingual nitrates are easiest to administer without the need of venous access. TTT can be combined with carotid sinus massage to evaluate carotid sinus hypersensitivity, which may not be present in supine position. TTT is not useful to access the response to treatment. Recently, implantable loop recorders (ILR) have been used to document cardioinhibitory reflex syncope, because pacemakers are beneficial in many of these patients, especially those over 45 years of age. The stepwise use of both TTT and ILR is a promising approach in these patients. Recently, TTT has been used for indications other than syncope, such as assessment of autonomic function in Parkinson's disease and its differentiation from multiple system atrophy.

Syncope in the Elderly

A rapid change in ageing demographic is taking place worldwide such that healthcare professionals are increasingly treating old and very old patients. Syncope in the elderly is a challenging presentation that is under-recognised, particularly in the acute care setting. The reason for this is that presentation in the older person may be atypical: patients are less likely to have a prodrome, may have amnesia for loss of consciousness and events are frequently unwitnessed. The older patient thus may present with a fall rather than transient loss of consciousness. There is an increased susceptibility to syncope with advancing age attributed to age-related physiological impairments in heart rate and blood pressure, and alterations in cerebral blood flow. Multi-morbidity and polypharmacy in these complex patients increases susceptibility to syncope. Cardiac causes and more than one possible cause are also common. Syncope is a major cause of morbidity and mortality and is associated with enormous personal and wider health economic costs. In view of this, prompt assessment and early targeted intervention are recommended. The purpose of this article is to update the reader regarding the presentation and management of syncope in this rapidly changing demographic.