Various non-electrocardiogram (ECG) based methods are considered reliable sources of heart rate variability (HRV) measurement. However, the ultra-short recording of a femoral arterial waveform has never been validated against the gold-standard ECG-based 300s HRV and was the aim of this study.A validity study was conducted using a sample from the first follow-up of the longitudinal ADVANCE study UK. The participants were adult servicemen (n = 100); similar in age, rank, and deployment period (Afghanistan 2003-2014). The femoral arterial waveforms (14s) from the pulse wave velocity (PWV) assessment, and ECG (300s) were recorded at rest in the supine position using the Vicorder™ and Bittium Faros™ devices, respectively, in the same session. HRV analysis was performed using Kubios Premium. Resting heart rate (HR) and root mean square of successive differences (RMSSD) were reported. The Bland-Altman %plots were constructed to explore the PWV-ECG agreement in HRV measurement. A further exploratory analysis was conducted across methods and durations.The participants\' mean age was 38.0 ± 5.3 years. Both PWV-derived HR (r = 0.85) and RMSSD (rs=0.84) showed strong correlations with their 300s-ECG counterparts (p < 0.001). Mean HR was significantly higher with ECG than PWV (mean bias: -12.71 ± 7.73%, 95%CI: -14.25%, -11.18%). In contrast, the difference in RMSSD between the two methods was non-significant [mean bias: -2.90 ± 37.82% (95%CI: -10.40%, 4.60%)] indicating good agreement. An exploratory analysis of 14s ECG-vs-300s ECG measurement revealed strong agreement in both RMSSD and HR.The 14s PWV-derived RMSSD strongly agrees with the gold-standard (300s-ECG-based) RMSSD at rest. Conversely, HR appears method sensitive.

This study was designed to evaluate the effects on hand catalepsy on parasympathetic tone assessed using Analgesia/Nociception Index (ANI) and on subjective rating of absorption, dissociation, and time perception among healthy volunteers. This was a randomized controlled trial including participants to a medical hypnosis congress in France. Ninety volunteers were randomized in two arms, all receiving a fifteen-minute positive hypnotic trance, with or without hand catalepsy. The relative parasympathetic tone assessed by ANI (Analgesia/Nociception Index), heart rate and respiratory rate were recorded at different times of the study protocol. The actual duration of the hypnotic session, calculated from eye closing to eye opening, was also recorded. At the end of the hypnotic trance, participants subjectively rated their level of absorption and dissociation on a 0-10 scale. They were also asked to estimate the duration of the hypnotic session from eye closing to eye opening. In total, ninety subjects were included in the study. One subject was excluded because of deviation in the protocol standard, leaving eighty-nine subjects for analysis. Subject characteristics were similar between groups. There was a statistically different increase in ANI and decrease in both heart rate and respiratory rate over time with no difference with or without hand catalepsy. There was no statistically significant difference in absorption and dissociation subjective scales between groups. The median [Q1-Q3] actual duration of hypnotic sessions was similar between the catalepsy and the control groups (9 [8-10] min vs. 8 [7-10] min, respectively). However, subjects in the catalepsy group estimated a longer duration of the hypnotic session (12 [10-15] min) than in the control group (10 [5-10] min) with a mean ± SD overestimation of 3 ± 4 min (p < 0.001). Parasympathetic comfort increased during the hypnotic trance with no difference between groups. However, adding hand catalepsy to a pleasant hypnotic trance did not appear to increase feelings of absorption or dissociation but created time distortion on the longer side that could be useful in some clinical settings. Nevertheless, further study is still needed to determine more precisely the physiological and psychological effects on hand catalepsy during the hypnotic trance.

Chronic treatment with acetylcholinesterase inhibitors may be a promising therapeutic strategy for treatment of cardiovascular diseases. The aim of our study was to analyze the changes in blood pressure (BP) and heart rate (HR) during 14 days of treatment with two different acetylcholinesterase inhibitors - pyridostigmine (PYR) having only peripheral effects or donepezil (DON) with both peripheral and central effects. In addition, we studied their effects on the cardiovascular response to restraint stress and on sympathovagal control of HR in normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). SHR were characterized by elevated BP and increased low-frequency component of systolic BP variability (LF-SBPV), but their cardiac vagal tone and HR variability (HRV) were reduced compared with WKY. Chronic treatment with either acetylcholinesterase inhibitor decreased HR and increased HRV in both strains. PYR treatment slightly decreased BP and LF-SBPV in the dark phase of the day. Neither drug significantly altered BP response to stress, but PYR attenuated HR increase during restraint stress. Regarding sympathovagal balance, acute methylatropine administration caused a greater increase of HR in WKY than in SHR. Chronic PYR or DON treatment enhanced HRV and HR response to methylatropine (vagal tone) in WKY, whereas PYR but not DON treatment potentiated HRV and vagal tone in SHR. In conclusion, vagal tone was lower in SHR compared with WKY, but was enhanced by chronic PYR treatment in both strains. Thus, chronic peripheral, but not central, acetylcholinesterase inhibition has major effects on HR and its variability in both normotensive and hypertensive rats.

BACKGROUND: A considerable link between personality types and cardiovascular diseases (CVDs) has been seen. Autonomic responses in both type A and type B personality individuals were found to be influenced by their personality traits. The study suggests further research on cardiac autonomic functions in larger sample sizes and the use of non-invasive screening techniques like cardiovascular reflex tests to stratify participants\' risk of future illness.
OBJECTIVE: This study aimed to assess autonomic stress reactivity tests in type A and type B personalities using cardiovascular reflex tests.
METHODS: This study was conducted at the Department of Physiology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi. The Hunter-Wolf Personality Questionnaire Scale was used to identify 60 adults, 30 of whom were classified to have type A personality and 30 have type B personality, from the psychiatry department. Autonomic function tests, such as the handgrip tests, cold pressor test, deep breathing test (DBT), lying-to-standing test (LST), and Valsalva maneuver, were performed and recorded for each subject. IBM SPSS Statistics for Windows, version 21 (released 2012; IBM Corp., Armonk, New York, United States) was used for the compilation and analysis of data.
RESULTS:  The E:I (expiration-to-inspiration) ratio and delta heart rate of the type A personality patients both significantly decreased (p = 0.000*) as compared to the type B personality patients (1.18 ± 0.03 versus 1.25 ± 0.77 and 1.18 ± 0.03 versus 1.25 ± 0.77). The Valsalva ratio of the type A personality patients decreased (1.38 ± 0.10) as compared to the type B personality patients (1.48 ± 0.18), which was statistically significant (p = 0.001*). The 30:15 ratio in the type A personality patients was significantly decreased (p = 0.03*) compared to the type B personality patients (1.12 ± 0.05 versus 1.15 ± 0.10). The handgrip test and cold pressor test results were statistically insignificant.
CONCLUSIONS: Compared to the type B personality patients, which exhibited an increase in both parasympathetic and sympathetic reactivity, the type A personality patients exhibited a reduction in resting cardiovascular parameters and resting autonomic tone. Consequently, in order to stratify the participants\' risk of future illness, we recommend employing non-invasive procedures, such as cardiovascular reflex tests, as a screening technique.

Atrioventricular (AV) block in pregnancy is rare, but it is a serious arrhythmia that needs to be carefully managed in pregnancy. However, as of now, there are no clear guidelines or consensus for intrapartum management. Most of the time, an intrapartum AV block is secondary to hypervagatonic sinus node dysfunction and is treated conservatively. Hypervagatonic sinus node dysfunction has a heterogeneous presentation of AV block, and pseudo-Mobitz type II in labor is rarely reported. We report a case of pseudo-Mobitz type II AV block during pregnancy due to labor pain, which is successfully managed conservatively.

This study investigates the potential impact of cholinesterase inhibitors (ChEIs) on patients with heart failure (HF) and dementia. ChEIs are known to boost acetylcholine levels and benefit cognition in patients with dementia; however, their effect on patients with HF is uncertain. This study aimed to assess whether cardiovascular events and mortality among patients with HF and dementia are altered by ChEI therapy.
Data from the National Health Insurance Research Database in Taiwan were retrospectively analyzed. Dementia patients diagnosed with HF were followed for 5 years until all-cause mortality, cardiovascular mortality, hospitalization for worsening HF, or the end of the study. Multivariable Cox models and inverse probability of treatment weighting (IPTW) were employed.
Out of 20,848 patients with dementia, 5138 had HF. Among them, 726 were ChEI users and 4412 were non-users. Based on IPTW, the ChEI users had significantly lower estimated risks of all-cause mortality [hazard ratio (HR) 0.43; 95% confidence interval (CI) 0.38-0.49, p < 0.001] and cardiovascular mortality (HR 0.41; 95% CI 0.33-0.53, p < 0.001) compared with the non-users, but there was no significant difference in hospitalization for worsening HF (HR 0.73; 95% CI 0.51-1.05, p = 0.091) after 5 years. The survival benefits of ChEIs were consistent across subgroups.
The results of this retrospective cohort study suggest that ChEIs may be beneficial in reducing all-cause and cardiovascular mortality in patients with dementia with HF. Further research is needed to validate these findings and explore the potential benefits of ChEIs in all patients with HF, including those without dementia.

Habitual physical activity improves heart functions and parasympathetic tone; Karate training is considered as a moderate physical activity with rhythmical breathing patternology. Heart rate variability (HRV) is an electrophysiological tool which measures cardio autonomic homeostasis; is used in the present study as an indirect marker to measure neurocognitive development with karate training. The aim of the present study was to find out the impact of regular karate training on cardiac autonomic responses through Heart Rate Variability (HRV) between karate players and age-sex matched active controls. A total of 30 male school-going children were evaluated; fifteen were experienced male karate practitioners (9.5±1.26 years) and fifteen controls (10.6±1.57 years). The time and frequency domain measures of HRV were taken into account after check for normality distribution, followed by t-test for comparison of Mean±SD. Frequency domain measures; low frequency normalized unit (LF nu) and low frequency is to high frequency ratio (LF/HF ratio) both showed significant reduction in the karate group which quantified sympathetic disposition while High frequency normalized units (HF nu) reflected a significant rise and it predicted increase in parasympathetic tone. Karate practitioners show higher HRV measures and more involvement of the parasympathetic nervous system which help in stress resilience and improved recovery time. This training if performed regularly from an early age can improve cardiac health which is very pertinent in the present times.

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The autonomic profile of mice submitted to sustained hypoxia (SH) was not yet fully evaluated. Herein, we characterized the cardiovascular and autonomic profile of conscious freely moving mice submitted to SH using two sequential experimental protocols to evaluate the parasympathetic and sympathetic tone to the heart and the sympathetic tone to the vascular resistance. In the first protocol the sequence of antagonists was methyl-atropine followed by propranolol and then by prazosin, while in the second protocol the sequence was propranolol followed by methyl-atropine and then by prazosin. In SH the baseline heart rate was significantly lower than in control mice and the antagonism of the parasympathetic and sympathetic tone to the heart in both experimental protocols indicated an increased parasympathetic tone in SH mice and no changes in the sympathetic tone. Antagonism of the sympathetic tone to the vascular resistance with prazosin produced similar changes in arterial pressure in control and SH mice. Altogether these findings support the concept that mice submitted to SH present a significant increase in the parasympathetic but not in the sympathetic tone, which may explain why the baseline arterial pressure was not increased in SH mice.

BACKGROUND: Pranayama, a yogic breathing practice, produces several physiological responses in healthy individuals. Hypertension is a critical and booming public health challenge all over the world. Yoga is one of the effective methods to reduce blood pressure (BP) and pulse rate (PR).
OBJECTIVE: To evaluate the effect of left nostril breathing (LNB) exercise on cardiorespiratory parameters and reaction time (RT) in young healthy individuals.
METHODS: In this study, 106 young healthy individuals between 18 and 25 years of age were included. The systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse rate (PR), respiratory rate (RR), vital capacity (VC), peak expiratory flow rate (PEFR), and reaction time (RT) of volunteers were recorded at baseline (before exercise) and after two weeks of left nostril breathing exercise performed 45 minutes daily.
RESULTS:  There was a significant reduction in SBP (126.64 ± 15.51 mmHg versus 116.29 ± 11.91 mmHg; Cohen\'s d (effect size): 0.87; p < 0.0001)), DBP (76.57 ± 14.87 mmHg versus 71.07 ± 11.39 mmHg; Cohen\'s d: 0.48; p < 0.0001), PR (85.32 ± 15.44/minute versus 81.77 ± 13.02/minute; Cohen\'s d: 0.27; p < 0.0001), and RR (14.26 ± 2.15/minute to 13.17 ± 2.03/minute; Cohen\'s d: 0.54; p < 0.0001). A significant increase was observed in VC (3.42 ± 0.62 versus 3.67 ± 0.65; Cohen\'s d: 0.39; p < 0.0001) and PEFR (467.81 ± 46.66 versus 498.29 ± 51.50; Cohen\'s d: 0.59; p < 0.0001). There was a significant decrement in auditory reaction time (ART) (164.36 ± 27.20 ms versus 143.84 ± 20.32 ms; Cohen\'s d: 0.85; p < 0.0001) and visual reaction time (VRT) (190.25 ± 31.48 ms versus 163.75 ± 21.72 ms; Cohen\'s d: 0.98; p < 0.0001). There was no significant change in maximum heart rate (MHR) after cardiorespiratory activity (CRA) (p > 0.434).
CONCLUSIONS: Left nostril breathing is associated with a decrease in cardiovascular parameters and an increase in VC and PEFR. This technique may be useful for putting up a fight against the stress and strain of daily life. This simple exercise may also be a beneficial adjuvant to pharmacological therapy in hypertensive patients.