Resting Heart Rate Variability Is Associated With Subsequent Orthostatic Hypotension: Comparison Between Healthy Older People and Patients With Rapid Eye Movement Sleep Behavior Disorder

Abstract

Background: Orthostatic hypotension (OH) caused by autonomic dysfunction is a common symptom in older people and patients with idiopathic rapid eye movement sleep behavior disorder (iRBD). The orthostatic challenge test is a standard autonomic function test that measures a decrease of blood pressure during a postural change from supine to standing positions. Although previous studies have reported that changes in heart rate variability (HRV) are associated with autonomic dysfunction, no study has investigated the relationship between HRV before standing and the occurrence of OH in an orthostatic challenge test. This study aims to examine the connection between HRV in the supine position and the occurrence of OH in an orthostatic challenge test.Methods: We measured the electrocardiograms of patients with iRBD and healthy older people during an orthostatic challenge test, in which the supine and standing positions were held for 15 min, respectively. The subjects were divided into three groups: healthy controls (HC), OH-negative iRBD [OH (–) iRBD], and OH-positive iRBD [OH (+) iRBD]. HRV measured in the supine position during the test were calculated by time-domain analysis and Poincaré plots to evaluate the autonomic dysfunction.Results: Forty-two HC, 12 OH (–) iRBD, and nine OH (+) iRBD subjects were included. HRV indices in the OH (–) and the OH (+) iRBD groups were significantly smaller than those in the HC group. The multivariate logistic regression analysis for OH identification for the iRBD groups showed the model whose inputs were the HRV indices, i.e., standard deviation 2 (SD2) and the percentage of adjacent intervals that varied by more than 50 ms (pNN50), had a receiver operating characteristic curve with area under the curve of 0.840, the sensitivity to OH (+) of 1.000, and the specificity to OH (–) of 0.583 (p = 0.023).Conclusions: This study showed the possibility that short-term HRV indices in the supine position would predict subsequent OH in iRBD patients. Our results are of clinical importance in terms of showing the possibility that OH can be predicted using only HRV in the supine position without an orthostatic challenge test, which would improve the efficiency and safety of testing.

Heart Rate Variability in evaluation of autonomic dysfunction in idiopathic REM-sleep behaviour disorder

“…The explanation for this could be that HRV is closely related to cardiac autonomic function, while the CVS domain in the NMSS questionnaire mostly concerns orthostasis, which more accurately represents peripheral vascular autonomic function, or it could be that the subjective nature of questionnaire--assessed dysautonomia in NMSS does not reflect all of the aspects of CVS function. However, Sumi et al demonstrated that the decrease in HRV indices during the supine position can predict orthostatic hypotension, providing an alternative to the orthostatic challenge test [32]. While using the headup tilt test, Rocchi et al [33] described LF and LF/HF ratio as significantly higher in controls compared to iRBD, while we did not find statistically significant differences between both groups.…”

Autonomic modulation and the risk of dementia in a middle-aged cohort: A 17-year follow-up study

“…Although vascular dementia and neurodegeneration differs somewhat in their disease characteristics, they may share similar risk factors in their pathophysiology [ 2 , 63 ]. For example, reduced parasympathetic tone and sympathetic-vagal imbalance are related to orthostatic hypotension [ [64] , [65] , [66] , [67] ], which might be a culprit for transient cerebral hypo-perfusion and subsequent brain damage and subsequent development of both vascular dementia and Alzheimer's disease [ 61 , 63 ]. In addition, accumulated evidence has indicated that impaired autonomic activity is related to elevated blood pressure, including both pre-hypertension and hypertensive status [ [68] , [69] , [70] , [71] ], which has been shown to have a dose–response effect on risk of both vascular dementia and neurodegeneration at midlife [ 72 , 73 ].…”

Predicting patient decompensation from continuous physiologic monitoring in the emergency department

“…This discrepancy may derive from correlations among embedding dimensions and other features. In the fully featured hypotension model, which performs similarly to the more restrictive, best-performing model, blood pressure trends are supplemented by perfusion index and an HRV metric, which has previously been associated with incipient hemodynamic collapse 52 , 53 . Overall, our feature analysis suggests that the assessment period is highly valuable for the prediction of hypotension, as the best-performing model is able to correctly reclassify visits that would otherwise be erroneously flagged as high-risk by a simpler model solely relying on lower blood pressures at triage.…”