Vasovagal Syncope in the Older Patient

Maw Pin Tan, BMedSci, BMBS, MRCP; Steve Parry, M.B.B.S., F.R.C.P.

Disclosures

Cardiosource 

In This Article

Vasovagal Syncope in the Older Patient

Vasovagal syncope (VVS) is traditionally assumed to primarily affect younger patients and only seen rarely in the elderly. However, since tilt-table testing was first described as a diagnostic test in 1986,[15] VVS has been diagnosed with increasing frequency in older patients, with recent reports suggesting a bimodal incidence with peaks at ages of 20-29 years and over 70 years (Figure 2).[16]

Age of Onset Vasovagal Syncope

Complicating efforts to determine the prevalence of syncope is the fact that epidemiological data are likely to represent underestimates due to the lack of systematic approaches to the evaluation of syncope.[17] In our state-of-the-art paper published in the February 12 issue of the Journal of the American College of Cardiology,[14] we conducted a comprehensive review of the current literature surrounding epidemiology, pathophysiology, clinical features, and treatment of VVS in the older patient, outlining key areas for future research.

The study of syncope in older patients is more challenging than it is in younger patients given that prevalence data and clinical outcomes both are complicated by the multiple potential causes of VVS.[18] Moreover, there is an overlap among older subjects between VVS, orthostatic hypotension (OH), and carotid sinus hypersensitivity (CSH).[19] There is also an overall blunting in autonomic response with increasing age.[20] Finally, complicating matters even further, while younger patients with VVS are expected to have normal life expectancies, this may not necessarily be true in older patients.

Based on the patterns of hemodynamic responses to tilt-table testing, younger subjects are more likely to demonstrate a classical response: a sudden drop in blood pressure and heart rate (Figure 3).[21] Older subjects, on the other hand, tend to display a more gradual (and usually asymptomatic) reduction in hemodynamic parameters or a dysautonomic response, culminating in abrupt loss of consciousness (Figure 4). Furthermore, bradycardic responses are more common in younger subjects, while hypotensive responses are more common in older subjects.[22]

Classic Vasovagal Syncope

Dysautonomic Vasovagal Syncope

Another age-related difference: The classical prodromal symptoms of pallor, tachycardia, sweating, nausea, abdominal discomfort or light headedness described by patients with VVS can be of very short duration or even nonexistent in older individuals.[23] CSH, a related neurally-mediated disorder, has been associated with unexplained falls and transient amnesia due to loss of consciousness[24] and deep white matter hyperintensities on magnetic resonance imaging.[25] Vasovagal syncope in younger subjects is associated with a reduced quality of life,[26] while falls in the elderly are linked to adverse psychological effects[27] and increased institutionalization.[28] There are, however, no published data looking directly at the social and psychological consequences of VVS in the elderly.

History and clinical examination alone can be diagnostic in many patients with VVS, but older patients are more likely to require head up tilt-table (HUTT) testing to confirm the diagnosis due to the lack of prodromal symptoms. While passive drug-free HUTT tests are less sensitive in older subjects,[29] the sensitivity of glyceryl-trinitrate induced HUTT testing in older patients is comparable to younger subjects.[30]

Few treatments for VVS have been evaluated in older populations. The PC-Trial demonstrated that the physical counter (PC) maneuvers of arm tensing and leg crossing are effective in reducing the recurrence of syncope (Figure 5),[31] but no subject over the age of 70 was included. Despite promising results from earlier studies using beta-adrenoreceptor blockers, the recent Prevention of Syncope Trial (POST)[32] did not show any significant benefit. However, there was a weak trend towards benefit in subjects aged 42 years or older (Figure 6).

Counter Pressure Maneuvers vs. Conventional Treatment

POST: Syncope-Free Survival

Studies involving permanent cardiac pacing tend to involve older subjects than those involving drugs. The second Vasovagal Pacemaker Study (VPS-II)[33] and the Vasovagal Syncope and Pacing trial (SYNPACE)[34] both compared permanent cardiac pacing with placebo, but did not show any reduction in syncopal events with cardiac pacing (Figure 7). However, future studies using different patient selection criteria and alternative pacing methods or closed-loop stimulation and contractility-driven DDDR pacing are needed. Other interventions, including salt supplementation, fludrocortisone, midodrine, and tilt training, have been evaluated, too, but only in small studies involving mainly younger subjects.

Time to First Syncope

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