BACKGROUND: Cardioinhibition may diminish with age, but the changing balance of cardioinhibition and vasodepression with age has not been quantified, leaving the mechanism of vasovagal syncope (VVS) in old age unclear.
OBJECTIVES: This study sought to quantify age-related changes of vasodepression and cardioinhibition in tilt-induced VVS.
METHODS: We studied 163 cases of tilt-induced VVS, evoked using the Italian protocol with blood pressure, heart rate, and video-electroencephalographic monitoring. Presyncope was excluded. Cardioinhibition was defined as the heart rate decrease before syncope; asystolic pauses (≥3 seconds) were divided into early and late asystole, ie, beginning early enough to or too late to be the major cause of loss of consciousness. The log-ratio method was used to quantify contributions of cardioinhibition and vasodepression, assessed in 2 10-second periods before the onset of cardioinhibition and before syncope.
RESULTS: With increasing age, cardioinhibition decreased, ie, heart rate decreased less and more slowly near syncope (P < 0.0001), while vasodepression increased. Asystolic pauses were less frequent in the older one-half of the group than the younger one-half (26% vs 57%; P < 0.00001), but when it did, late asystole occurred more often (58% vs 15%; P < 0.001).
CONCLUSIONS: The shift toward less cardioinhibition and more vasodepression with increased age probably reflects a physiological shift in circulatory control. The weakening of cardioinhibition with age may detract from the efficacy of pacing in older patients with VVS. Cardioinhibition-vasodepression balance should be considered in pacing decisions in older subjects with VVS.
Bibliographical noteFunding Information:
Dr de Lange has received consulting fees from Medtronic Inc, Abbott, and Daiichi-Sankyo. Dr Thijs has received consulting and speaker fees from Union Chimique Belge, GlaxoSmithKline, Theravarance, Arvelle, Novartis, and Zogenix; and has received grants from Dutch National Epilepsy Fund, Michael J. Fox Foundation for Parkinson's Research (MJFF-020200), Christelijke Vereniging voor de Verpleging van Lijders aan Epilepsie, Medtronic Inc, New Life Wearables, and the Netherlands Organisation for Health Research and Development (114025101). Dr Sutton has served as a consultant to Medtronic Inc; has been a member of the Speakers Bureau of Abbott Corp (St. Jude Medical); and is a stockholder of Edwards Lifesciences Corp and Boston Scientific Corp. Dr Benditt has served as a consultant to Medtronic Inc; and is a stockholder of Advanced Circulatory Systems. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
© 2022 American College of Cardiology Foundation
- autonomic nervous system
- Blood Pressure
- Heart Rate
- Syncope, Vasovagal/etiology
- Heart Arrest
- Tilt-Table Test/methods
PubMed: MeSH publication types
- Research Support, Non-U.S. Gov't
- Journal Article