Age and hemodynamic responses to tilt testing in those with syncope of unknown origin

Abstract

There appear to be distinct pathophysiologies underlying vasovagal syncope in different age groups. Young people appear to have excessive cardiac and autonomic responses to stress, whereas older patients appear to have a more generalized cardiovascular decline, with attenuated cardiac and autonomic responses to stress.

Usefulness of tilt-induced heart rate changes in the differential diagnosis of vasovagal syncope and chronic autonomic failure

“…Age is an important factor. Similar to others [11], and consistent with the age-related reduction in vagally mediated physiological phenomena, such as respiratory sinus arrhythmia [13], we found a trend of progressively less pronounced bradycardia during vasovagal syncope with advancing age: patients with type III vasodepressor syncope in the VASIS classification [16] were older than those with more pronounced bradycardia, classified as type IIA and IIB of the VASIS classification (30 ± 6 vs. 51 ± 5 years, P \ 0.05).…”

The pathophysiologic mechanisms associated with hypotensive susceptibility

“…Therefore, our results of a decrease in BRG with age could be explained by either the presence of a blunted efferent cardiovagal response of the reflex arc or intrinsic sinus node disease [21]. Our findings of the relationship between age and type of tilt response are aligned with the work of Kurbaan et al who showed that age was associated with greater prevalence of a vasodepressor response in older patients (>65 years; OR 29.5, p <0.0001) [24].…”

“…The authors found that patients with ages 31-50 years and >50 years old had a lower increase in HR during the first 20 minutes of tilt table testing when compared to patients younger than 30 years old. In another study by Kurbaan et al, the authors made a similar observation that age was associated with blunted HR response when compared to younger patients (OR 1.04, p<0.0002) [24]. Therefore, the observed blunted HR response might very well be related to age although its role in determining outcome remains unclear.…”

The Effect of Orthostatic Training in the Prevention of Vasovagal Syncope and Its Influencing Factors

“…17) Some previous studies regarded head-up tilt testing as the endpoint and thus obtained a distinctively different or even opposite conclusion. 18,19) This may be due to differences in the diagnostic tilt testing protocol. Some positive results can only be obtained by pharmacological stimulation, and thus the specificity of head-up tilt testing is greatly reduced.…”

“…Some positive results can only be obtained by pharmacological stimulation, and thus the specificity of head-up tilt testing is greatly reduced. 19) Moreover, repeat tilt testing for diagnostic purposes may have a limited role. Once patients have been tilted, their responses may change because they are aware of what to expect and attempt to respond.…”