Comparison of catecholamine response during tilt-table–induced vasovagal syncope in patients &lt;35 to those &gt;65 years of age

Ermis, Cengiz; Samniah, Nemer; Sakaguchi, Scott; Lurie, Keith G.; Pham, Scott; Lü, Fei; Benditt, David G.

doi:10.1016/j.amjcard.2003.09.047

Cited by 20 publications

(15 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…28,29 Notably, older patients are also less likely to have a positive isoproterenol tilt-table test, have a slower progression of symptoms during the test, and are more likely to develop presyncope than syncope. [30][31][32] This alone does not explain the clinically observed effect.…”

Section: Physiological Insightsmentioning

confidence: 86%

Age-Dependent Effect of β-Blockers in Preventing Vasovagal Syncope

Sheldon

Morillo

Klingenheben

et al. 2012

Circ: Arrhythmia and Electrophysiology

View full text Add to dashboard Cite

Background-β-blockers have little effectiveness in preventing vasovagal syncope in unselected populations, but they might be effective in older patients. We determined whether β-blockers prevent vasovagal syncope in an age-related fashion. Methods and Results-Two populations were studied. A proportional hazards analysis was performed on an observational cohort study of 153 patients with vasovagal syncope, 52 of whom received β-blockers. A multivariable proportional hazards model stratified by center was performed on 208 participants in the randomized Prevention of Syncope Trial (POST), examining the interaction between age group and treatment with metoprolol. Age-specific hazard ratios were estimated for both studies and combined using the inverse variance meta-analytic method. In the cohort study, the hazard ratio for syncope if treated with β-blockers was 1.54 (95% CI, 0.78-3.05) for patients aged <42 years and 0.48 (95% CI, 0.12-1.92) for patients aged ≥42 years. In POST, the proportional hazards model showed interactions between age and treatment effect (P=0.026). The hazard ratio for patients aged ≥42 years who received metoprolol was 0.53 (95% CI, 0.25-1.10); in patients aged <42 years, the hazard ratio was 1.62 (95% CI, 0.85-3.10). A pooled analysis of both studies yielded an estimate of the hazard ratio of 1.58 (CI, 1.00-2.31) for patients aged <42 years, and the hazard ratio was 0.52 (CI, 0.27-1.01) for patients aged ≥42 years. The 2 age groups differed significantly in response to β-blockers (P=0.007). Conclusions-β-blocker

show abstract

Section: Physiological Insightsmentioning

confidence: 86%

Age-Dependent Effect of β-Blockers in Preventing Vasovagal Syncope

Sheldon

Morillo

Klingenheben

et al. 2012

Circ: Arrhythmia and Electrophysiology

View full text Add to dashboard Cite

show abstract

“…This is, however, incompatible with the known effects of these changes in posture. Head-up tilting is well known to be accompanied by an increase in muscle sympathetic nerve activity (Cooke et al, 1999;Furlan et al, 2000;Saito et al, 1997;Shoemaker, Hogeman, Khan, Kimmerly, & Sinoway, 2001), noradrenergic spillover (Ermis et al, 2004;Esler et al, 1988;Furlan et al, 2000;Laszlo, Rossler, & Hinghofer-Szalkay, 2001), and cardiac contractility (Vijayalakshmi, Mohan, & Babu, 2002). Physiologically, this increase in sympathetic activity makes good sense.…”

Section: Discussionmentioning

confidence: 99%

Effects of variation in posture and respiration on RSA and pre‐ejection period

2005

View full text Add to dashboard Cite

The extent to which variation in posture and respiration can confound pre-ejection period and respiratory sinus arrhythmia (RSA) as indices of cardiac sympatho-vagal activity was examined. Within-subjects changes in these measures were assessed in 36 subjects during different postures and (paced) respiratory frequencies. Changes from supine to sitting to standing led to reduced RSA values and longer pre-ejection periods, reflecting the known decrease in vagal but not the increase of sympathetic activity. Multilevel path analysis showed that within-subjects changes in sympatho-vagal balance were faithfully reflected by changes in interbeat interval, but imperfectly by changes in RSA and pre-ejection period. It was concluded that pre-ejection period should be stratified for posture and RSA for respiratory frequency to reliably index changes in sympatho-vagal balance when these factors are prone to change (e.g., during 24-h ambulatory recording)

show abstract

“…27 However, measurement of arterial catecholamines in older adults (age >65 years) shows a tendency toward higher baseline adrenaline concentration, with less adrenaline surge before onset of syncope compared with younger adults (age <35 years), but with comparable noradrenaline responses. 28 Several other hormonal factors have been hypothesized to play a role in VVS; however, a clear pathophysiologic cause has yet to be shown. 29 Dynamic cerebral autoregulation is not affected by aging alone 30,31 and is preserved in older people, although disease states which do affect cerebral autoregulation, such as hypertension, are more common in the elderly.…”

Section: Neurally Mediated Syncopementioning

confidence: 99%