Surgical aortic valve replacement (SAVR) and transcatheter aortic valve implantation (TAVI) are options in severe aortic valve stenosis (AVS). Cardiovascular (CV) and cerebrovascular (CBV) control markers, derived from variability of heart period, systolic arterial pressure, mean cerebral blood velocity and mean arterial pressure, were acquired in 19 AVS patients (age: 76.8 ± 3.1 yrs, eight males) scheduled for SAVR and in 19 AVS patients (age: 79.9 + 6.5 yrs, 11 males) scheduled for TAVI before (PRE) and after intervention (POST, <7 days). Left ventricular function was preserved in both groups. Patients were studied at supine resting (REST) and during active standing (STAND). We found that: (i) both SAVR and TAVI groups featured a weak pre-procedure CV control; (ii) TAVI ensured better CV control; (iii) cerebral autoregulation was working in PRE in both SAVR and TAVI groups; (iv) SAVR and TAVI had no impact on the CBV control; (v) regardless of group, CV and CBV control markers were not influenced by STAND in POST. Even though the post-procedure preservation of both CV and CBV controls in TAVI group might lead to privilege this procedure in patients at higher risk, the missing response to STAND suggests that this advantage could be insignificant.

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BACKGROUND: Subarachnoid hemorrhage (SAH) patients with cerebral autoregulation (CA) impairment at an early post-SAH period are at high risk of unfavorable outcomes due to delayed cerebral ischemia (DCI) or other complications. Limited evidence exists for an association between early-stage CA impairments and SAH patient outcomes. The objective of this prospective study was to explore associations between CA impairments detected in early post-SAH snapshot examinations and patient outcomes.
METHODS: The pilot observational study included 29 SAH patients whose CA status was estimated 2-3 days after spontaneous aneurysm rupture and a control group of 15 healthy volunteers for comparison. Inflatable leg recovery boots (reboots.com, Germany) were used for the safe controlled generation of arterial blood pressure (ABP) changes necessary for reliable CA examination. At least 5 inflation‒deflation cycles of leg recovery boots with a 2-3 min period were used during examinations. CA status was assessed according to the delay time (∆TCBFV) measured between ABP(t) and cerebral blood flow velocity (CBFV(t)) signals during artificially induced ABP changes at boot deflation cycle. CBFV was measured in middle cerebral artery by using transcranial Doppler device.
RESULTS: Statistically significant differences in ∆TCBFV were found between SAH patients with unfavorable outcomes (∆TCBFV = 1.37 ± 1.23 s) and those with favorable outcomes (∆TCBFV = 2.86 ± 0.99 s) (p < 0.001). Early assessment of baroreflex sensitivity (BRS) during the deflation cycle showed statistically significant differences between the DCI and non-DCI patient groups (p = 0.039).
CONCLUSIONS: A relatively small delay of ∆TCBFV <1.6 s between CBFV(t) and ABP(t) waves could be an early warning sign associated with unfavorable outcomes in SAH patients. The BRS during boot deflation can be used as a biomarker for the prediction of DCI.
BACKGROUND: ClinicalTrials.gov Identifier: NCT06028906. Registered 31 August 2023 - Retrospectively registered, https://www.
RESULTS: gov/study/NCT06028906 .

We investigated the effect of levodopa on postural blood pressure changes in individuals with Parkinson disease (PD) with (PD+OH) and without neurogenic OH (PD-OH).
We performed a prospective randomized crossover study with autonomic testing performed ON and OFF levodopa. The primary outcome was the change in systolic blood pressure (SBP) from supine to 70° tilt at 3 min (ΔSBP-3\'). Secondary outcomes included indices of baroreflex function and blood pressure and heart rate during tilt.
We enrolled 40 individuals with PD (21 PD+OH, 19 PD-OH), mean age (SD) 73.2 years (7.9), 13 women (32.5%)). There was no difference in age, sex, disease duration, and severity between PD+OH and PD-OH. Mean difference in ΔSBP-3\' ON versus OFF levodopa in the whole study population was - 3.20 mmHg [- 7.36 to 0.96] (p = 0.14). Mean difference in ΔSBP-3\' was - 2.14 mmHg [- 7.55 to 3.28] (p = 0.45) in PD+OH and - 5.14 mmHg [- 11.63 to 1.35] (p = 0.14) in PD-OH. Mean difference in ΔSBP ON versus OFF levodopa was greater at 7 and 10 min (- 7.52 mmHg [- 11.89 to - 3.15], p = 0.002, and - 7.82 mmHg [- 14.02 to - 1.67], p = 0.02 respectively). Levodopa was associated with lower absolute values of blood pressure in both PD+OH and PD-OH and cardiovascular noradrenergic baroreflex impairment.
Levodopa decreases blood pressure in both PD with and without autonomic failure, but it does not cause a greater fall in blood pressure from supine to standing at 3 min. Levodopa-induced baroreflex sympathetic noradrenergic impairment may contribute to lower blood pressure. Lower standing blood pressure with levodopa may increase the risks of fall and syncope.

OBJECTIVE: The study aimed to explore risk stratification approaches for cardiovascular autonomic neuropathy (CAN) in individuals with prediabetes and type 2 diabetes (T2DM) over a three-year follow-up period.
METHODS: Participants underwent evaluations of autonomic function encompassing cardiovascular autonomic reflex tests (CARTs), baroreflex sensitivity (BRS), heart rate variability (HRV) in time domains (standard deviation of all normal RR intervals (SDNN)) and frequency domains (high frequency/low frequency ratio), and electrochemical skin conductance (ESC). The diagnosis of CAN relied on abnormal CART results. Subjects were categorized into 4 groups, based on their assessment of cardiac autonomic function at 3-year follow-up, relative to the presence or absence of CAN at baseline assessment: Persistent absence of CAN; Resolution of CAN; Progression to CAN; and Persistent CAN.
RESULTS: Participants with T2DM/prediabetes (n = 91/7) were categorized as: Persistent absence of CAN (n = 25), Resolution of CAN (n = 10), Progression to CAN (n = 18), and Persistent CAN (n = 45) groups. The Persistent absence of CAN group showed significant associations with SDNN. The Resolution of CAN group exhibited notable associations with mean HbA1C (follow-up), while the Progression to CAN group displayed a significant link with baseline estimated glomerular filtration rate. The Persistent CAN group demonstrated significant associations with SDNN and Sudoscan CAN risk score. Screening recommendations involve biennial to annual assessments based on risk levels, aiding in CAN detection and subsequent comprehensive and time-intensive autonomic function tests for confirmation. The study\'s findings offer improved risk categorization approaches for detecting CAN, which has relevance for shaping public health strategies.

Heart rate and vascular tension baroreflex exhibit resonance characteristics at approximately 0.1 and 0.03 Hz. In this study, we aimed to induce postural resonance (PR) through rhythmic postural adjustments. To assess the viability of this technique, we investigated the acute impacts of postural resonance on blood pressure, sympathetic nerve activity, and mood. Fifteen healthy study participants, consisting of 8 males and 7 females, were selected for this self-controlled study. Skin sympathetic nerve activity was continuously monitored during both the intervention and stress test on the experimental day. After PR intervention, the diastolic blood pressure and mean arterial pressure in the PR group exhibited significant reductions compared to the CON group (P = 0.032, CON = 71.67 ± 2.348, PR = 64.08 ± 2.35; P = 0.041, CON = 75.00 ± 2.17, PR = 81.67 ± 2.17). After PR intervention both left brachial ankle pulse wave velocity and right brachial ankle pulse wave velocity exhibited a significant reduction compared to pre-intervention levels (from 1115.86 ± 150.08 to 1048.43 ± 127.40 cm/s, p < 0.001; 1103.86 ± 144.35 to 1060.43 ± 121.35 cm/s, p = 0.018). PR intervention also led to a significant decrease in burst frequency and duration (P = 0.049; CON = 8.96 ± 1.17, PR = 5.51 ± 1.17) and a noteworthy decrease in burst amplitude and burst threshold during the cold-pressor test (P = 0.002; P = 0.002). Additionally, VAS scores exhibited a substantial increase following PR (P = 0.035, CON = 28.4 ± 4.49, PR = 42.17 ± 4.10). PR can induce resonance effects within the cardiovascular system, resulting in the effective reduction of blood pressure, skin sympathetic nerve activity and pulse wave velocity, and decreased burst amplitude and burst threshold of the sympathetic nerve during the cold-pressor test.

Habitual coffee drinking is ubiquitous and generally considered to be safe despite its transient hypertensive effect. Our purpose was to determine the role of the sympathetic nervous system in the hypertensive response.
In a single-centre crossover study, medical caregivers were studied after consumption of standard coffee (espresso), water and decaffeinated coffee (decaff) given in random order at least 1 month apart. Plasma caffeine levels, mean arterial pressure, heart rate, total peripheral resistance and muscle sympathetic activity were recorded. Baroreflex activity was assessed using burst incidence and RR interval changes to spontaneous blood pressure fluctuations.
A total of 16 subjects (mean [± standard error] age 34.4 ± 2 years; 44% female) were recruited to the study. Three agents were studied in ten subjects, and two agents were studied in six subjects. Over a 120-min period following the consumption of standard coffee, mean (± SE) plasma caffeine levels increased from 2.4 ± 0.8 to 21.0 ± 4 µmol/L and arterial pressure increased to 103 ± 1 mmHg compared to water (101 ± 1 mmHg; p = 0.066) and decaff (100 ± 1 mmHg; p = 0.016). Peripheral resistance in the same period following coffee increased to 120 ± 4% of the baseline level compared to water (107 ± 4; p = 0.01) and decaff (109 ± 4; p = 0.02). Heart rate was lower after both coffee and decaff consumption: 62 ± 1 bpm compared to water (64 bpm; p = 0.01 and p = 0.02, respectively). Cardio-vagal baroreflex activity remained stable after coffee, but sympathetic activity decreased, with burst frequency of 96 ± 3% versus water (106 ± 3%; p = 0.04) and decaff (112 ± 3%; p = 0.001) despite a fall in baroreflex activity from - 2.2 ± 0.1 to - 1.8 ± 0.1 bursts/100 beats/mmHg, compared to water (p = 0.009) and decaff (p = 0.004).
The hypertensive response to coffee is secondary to peripheral vasoconstriction but this is not mediated by increased sympathetic nerve activity. These results may explain why habitual coffee drinking is safe.

The aim of this study was to evaluate the differences in performance during a decisional conflict task between subjects with emotional/blood phobia and those with an orthostatic vasovagal syncope. A total of 332 young subjects were included, from which 99 were excluded because of their condition or treatment. The subjects were classified into four groups depending on their responses to a questionnaire: 98 in a control group, 10 in an emotional/blood phobia syncope group, 38 in an orthostatic syncope group, and 87 in an unclear status group. This former group was excluded. The subjects performed a decisional conflict task to quantify their conflict-management ability. The task was the computer version of the Simon Task. Emotional/blood phobia syncope subjects showed a delayed reaction time when faced with decisional conflict in comparison with the control and orthostatic syncope subjects (55.8 ± 17.7 ms, 20.5 ± 4.9 ms, and 13.4 ± 9.2 ms, respectively, p ≤ 0.05). Our result suggests that emotional/blood phobia and orthostatic syncope are two clinical entities. Decisions could be a target of management in patients with emotional/blood phobia syncope. The altered decision-making of subjects with emotion/blood phobia syncope emphasized the role of higher cerebral functions in blood pressure control.

During flight, G force compels blood to stay in leg muscles and reduces blood flow to the heart. Cardiovascular responses activated by the autonomic nerve system and strengthened by anti-G straining maneuvers can alleviate the challenges faced during G loading. To our knowledge, no definite cardiac information measured using a mobile health device exists for analyzing G tolerance. However, our previous study developed the cardiac force index (CFI) for analyzing the G tolerance of military aircrew.
This study used the CFI to verify participants\' cardiac performance when walking and obtained a formula for predicting an individual\'s G tolerance during centrifuge training.
Participants from an air force aircrew undertook high-G training from January 2020 to December 2022. Their heart rate (HR) in beats per minute and activity level per second were recorded using the wearable BioHarness 3.0 device. The CFI was computed using the following formula: weight × activity / HR during resting or walking. Relaxed G tolerance (RGT) and straining G tolerance (SGT) were assessed at a slowly increasing rate of G loading (0.1 G/s) during training. Other demographic factors were included in the multivariate regression to generate a model for predicting G tolerance from the CFI.
A total of 213 eligible trainees from a military aircrew were recruited. The average age was 25.61 (SD 3.66) years, and 13.1% (28/213) of the participants were women. The mean resting CFI and walking CFI (WCFI) were 0.016 (SD 0.001) and 0.141 (SD 0.037) kg × G/beats per minute, respectively. The models for predicting RGT and SGT were as follows: RGT = 0.066 × age + 0.043 × (WCFI × 100) - 0.037 × height + 0.015 × systolic blood pressure - 0.010 × HR + 7.724 and SGT = 0.103 × (WCFI × 100) - 0.069 × height + 0.018 × systolic blood pressure + 15.899. Thus, the WCFI is a positive factor for predicting the RGT and SGT before centrifuge training.
The WCFI is a vital component of the formula for estimating G tolerance prior to training. The WCFI can be used to monitor physiological conditions against G stress.

Sympathovagal balance is important in the pathogenesis of hypertension and independently associated with mortality. We evaluated the value of automated analysis of cross-correlation baroreflex sensitivity (xBRS) and heart rate variability (HRV) and its relationship with clinical covariates in 13,326 participants from the multi-ethnic HELIUS study. Finger blood pressure (BP) was continuously recorded, from which xBRS, standard deviation of normal-to-normal intervals (SDNN), and squared root of mean squared successive difference between normal-to-normal intervals (RMSDD) were determined. A subset of 3356 recordings > 300 s was used to derive the minimally required duration by comparing shortened to complete recordings, defined as intraclass correlation (ICC) > 0.90. For xBRS and SDNN, 120 s and 180 s were required (ICC 0.93); for RMSDD, 60 s (ICC 0.94) was sufficient. We included 10,252 participants (median age 46 years, 54% women) with a recording > 180 s for the regression. xBRS, SDNN, and RMSDD decreased linearly up to 50 years of age. For xBRS, there was a signification interaction with sex, with for every 10 years a decrease of 4.3 ms/mmHg (95%CI 4.0-4.6) for men and 5.9 ms/mmHg (95%CI 5.6-6.1) for women. Using splines, we observed sex-dependent nonlinearities in the relation with BP, waist-to-hip-ratio, and body mass index. Future studies can help unravel the dynamics of these relations and assess their predictive value. Panel 1 depicts automatic analysis and filtering of finger BP recordings, panel 2 depicts computation of xBRS from interpolated beat to beat data of systolic BP and interbeat interval, and (IBI) SDNN and RMSDD are computed directly from the filtered IBI dataset. Panel 3 depicts the results of large-scale analysis and relation of xBRS with age, sex, blood pressure and body mass index.