Effect of Yoga-Based Cardiac Rehabilitation Program on Endothelial Function, Oxidative Stress, and Inflammatory Markers in Acute Myocardial Infarction: A Randomized Controlled Trial.

Aims: The aim of this study was to evaluate the effects of yoga-based cardiac rehabilitation (Yoga-CaRe) on the endothelial system, oxidative stress, and inflammatory markers in patients with acute myocardial infarction (MI). Methods: A sub-study was conducted in two clinical sites of the Yoga-CaRe trial (a multicenter randomized controlled trial). Participants with acute MI were randomized and allocated to either the Yoga-CaRe program (13 sessions with encouragement to home practice) or enhanced standard care (three educational sessions). Endothelial function, oxidative stress, and inflammatory biomarkers were assessed using biomarkers such as asymmetric dimethylarginine (ADMA), endothelial nitric oxide synthase (eNOS), endothelin-1 (ET-1), E-selectin, P-selectin, vascular cell adhesion molecule (VCAM), intercellular cell-adhesion molecule-1, total nitric oxide concentration (NOx), oxidized low-density lipoprotein (Oxd-LDL), superoxide dismutase, total antioxidant capacity (TAOC), tumor necrosis factor-alpha (TNFα), and C-reactive protein (CRP) at baseline and 12 weeks. Laboratory and statistical analysis were done by staff blinded to group allocation. Results: Eighty-two patients (of the 110 patients recruited) completed the study. The mean age was 53.1 ± 10.6 and 51.9 ± 10.7 years in enhanced standard care and Yoga-CaRe group, respectively. At 12 weeks, Yoga-CaRe significantly reduced ADMA, ET-1, and ICMA-1 than the enhanced standard care group. Although E-selectin and VCAM at 12 weeks were reduced in both groups, enhanced standard care had a significantly higher reduction than the Yoga-CaRe group. Among markers of oxidative stress, TAOC increased in the Yoga-CaRe group. We found no difference in eNOS, NOx, P-selectin, TNFα, CRP, and Oxd-LDL between the two groups. Conclusion: Yoga-CaRe improved the endothelial function (through a reduction in ET-1 and modulating adhesion molecules) and enhanced antioxidant capacity.

Cardiovascular Autonomic Deficits in Different Types of Achalasia.

Background and objective Achalasia cardia is a primary esophageal motility disorder, and the etiopathology of this disease's progression is not known. Moreover, autonomic dysfunction has not been studied in different types of achalasia. In light of this, we aimed to address this lack of data in this study. Methods The diagnosis of achalasia was done using high-resolution esophageal manometry (HRM)-based Chicago classification v4.0. Autonomic function tests (AFT) such as the head-up tilt test, deep breathing test (DBT), Valsalva maneuver (VM), handgrip test (HGT), and cold pressor test (CPT), as well as the heart rate variability (HRV) test, were performed among the cohort and the results were compared with those of 39 age- and sex-matched healthy controls. Results AFT and HRV tests were done on 62 patients (30 achalasia type I, 28 type II, and 4 type III) and compared with 39 age- and sex-matched healthy controls. The mean duration of symptoms, high Eckardt score, and dysphagia were most common in type I achalasia, followed by type II and III. The results of AFT showed a generalized loss of parasympathetic and baroreflex-independent sympathetic reactivity in all types of achalasia. However, baroreflex-dependent cardiovascular adrenergic reactivity was normal. Regarding cardiac autonomic tone, there was a loss of parasympathetic and sympathetic influence, but sympathovagal balance was maintained. The severity of the loss of autonomic functions was higher in type I, followed by type II. Conclusions In all types of achalasia, parasympathetic reactivity, baroreflex-independent sympathetic reactivity, and cardiac autonomic tone were lower compared to healthy controls, and the severity of dysfunction increased during the progression of the disease from type II to type I.

Baroreflex sensitivity is impaired in survivors of mild COVID-19 at 3-6 months of clinical recovery; association with carotid artery stiffness.

The association between the stiffening of barosensitive regions of central arteries and the derangements in baroreflex functions remains unexplored in COVID-19 survivors. Fifty-seven survivors of mild COVID-19 (defined as presence of upper respiratory tract symptoms and/or fever without shortness of breath or hypoxia; SpO2 > 93%), with an age range of 22-66 years (27 females) participated at 3-6 months of recovering from the acute phase of RT-PCR positive COVID-19. Healthy volunteers whose baroreflex sensitivity (BRS) and arterial stiffness data were acquired prior to the onset of the pandemic constituted the control group. BRS was found to be significantly lower in the COVID survivor group for the systolic blood pressure-based sequences (BRSSBP ) [9.78 (7.16-17.74) ms/mmHg vs 16.5 (11.25-23.78) ms/mmHg; p = 0.0253]. The COVID survivor group showed significantly higher carotid ß stiffness index [7.16 (5.75-8.18) vs 5.64 (4.34-6.96); (p = 0.0004)], and pulse wave velocity ß (PWVß ) [5.67 (4.96-6.32) m/s vs 5.12 (4.37-5.41) m/s; p = 0.0002]. BRS quantified by both the sequence and spectral methods showed an inverse correlation with PWVß in the male survivors. Impairment of BRS in the male survivors of mild COVID-19 at 3-6 months of clinical recovery shows association with carotid artery stiffness.

Vasoconstriction during non-hypotensive hypovolemia is not associated with activation of baroreflex: A causality-based approach.

Non-hypotensive hypovolemia simulated with oscillatory lower body negative pressure in the range of -10 to -20 mmHg is associated with vasoconstriction {increase in total peripheral vascular resistance (TPVR)}. Due to the mechanical stiffening of vessels, there is a disjuncture of mechano-neural coupling at the level of arterial baroreceptors which has not been investigated. The study was designed to quantify both the cardiac and vascular arms of the baroreflex using an approach based on Wiener-Granger causality (WGC) - partial directed coherence (PDC). Thirty-three healthy human volunteers were recruited and continuous heart rate and blood pressure {systolic (SBP), diastolic (DBP), and mean (MBP)} were recorded. The measurements were taken in resting state, at -10 mmHg (level 1) and -15 mmHg (level 2). Spectral causality - PDC was estimated from the MVAR model in the low-frequency band using the GMAC MatLab toolbox. PDC from SBP and MBP to RR interval and TPVR was calculated. The PDC from MBP to RR interval showed no significant change at -10 mmHg and -15 mmHg. No significant change in PDC from MBP to TPVR at -10 mmHg and -15 mmHg was observed. Similar results were obtained for PDC estimation using SBP as input. However, a significant increase in TPVR from baseline at both levels of oscillatory LBNP (p-value <0.001). No statistically significant change in PDC from blood pressure to RR interval and blood pressure to TPVR implies that vasoconstriction is not associated with activation of the arterial baroreflex in ≤-15 mmHg LBNP. Thereby, indicating the role of cardiopulmonary reflexes during the low level of LBNP simulated non-hypotensive hypovolemia.

Effect of Yoga Based Cardiac Rehabilitation on Blood Pressure Variability and Baroreflex Sensitivity: RCT in Patients Post MI.

To assess the effects of 12 weeks Yoga based Cardiac Rehabilitation program on Blood Pressure Variability and Baroreflex Sensitivity in Eighty patients post myocardial infarction. Randomized controlled trial with two parallel groups. A tertiary care institution in India. The Yoga group received 13 hospital-based structured yoga sessions in adjunct to the standard care. Control Group participants received enhanced standard care involving three brief educational sessions on importance of diet and physical activity. Beat to beat arterial pressure variability and baroreflex sensitivity was determined non-invasively. Baseline measurement was done at 3 weeks post Myocardial Infarction. The measurements were repeated at 13th week and at 26th week post MI. There was no significant difference between the groups in time domain indices of SBP variability. At 26th week post MI, after normalization the Low Frequency power increased in the yoga group as compared to the decrease in the standard care group (p = 0.02). Though the High Frequency power increased in both the groups, the magnitude of increase was higher in the standard care group (p = 0.005). However, the total power increased significantly in yoga group with a concurrent decrease in standard care group (p = < 0.001). The SBP All BRS was significantly different between the groups with an increase in the yoga group and a decline in standard care group (p = 0.003) at 13th week. A short-term Yoga based cardiac rehabilitation has additive effects in improving baroreflex sensitivity and dampening blood pressure variability post myocardial infarction in patients under optimal medication.The main trial is registered in Clinical Trials Registry-India (CTRI) (Ref. No: CTRI/2012/02/002408). In addition, CTRI has also been registered for the sub-study. (Ref. No: CTRI/2017/09/009925).

Temporal Analysis of Sequential Changes in Heart Rate Variability During Non-hypotensive Hypovolemia.

INTRODUCTION: Haemorrhage is associated with changes in the cardiac autonomic drive which begins during early stages of mild haemorrhage. The knowledge of chronology of the autonomic changes at smaller timescale during the period of haemorrhage can help identify the primary autonomic parameter which signals the institution of cardiovascular reflex mechanisms. AIM: To evaluate the heart rate variability in 2-min sequential segments with one minute overlap during and after the period of mild haemorrhage (450 ml) using blood donation as a model of acute blood loss. METHODS: 47 male blood donors who had volunteered for blood donation were recruited for the study. Continuous lead II ECG was recorded before the start of the blood donation (5 min), during the period of the blood donation (~ 5-7 min) and after blood donation (5 min). The parasympathetic and sympathetic drive to heart was estimated by measures of heart rate variability in time and frequency domain. RESULTS: A significant decrease in the parameters assessing parasympathetic drive i.e., normalised High frequency (HFn) and NN50 (Number of pairs of adjacent NN intervals differing by more than 50 ms) and pNN50 (NN50 divided by the total number of all NN Intervals) was observed during blood donation at 3-5 min, as compared to baseline. An increase in parameters associated with sympathetic drive i.e., normalised low frequency (LFn) was observed only in the post donation period at 2-3 min. A significant rise in LF/HF ratio which is a marker of sympatho vagal balance was observed at 4-5 min during blood donation when compared to baseline. CONCLUSION: The initial cardiac autonomic change during mild haemorrhage is withdrawal of parasympathetic drive, followed by an increase in sympathetic tone which occurs much later.

Predictive value of intraoperative D-wave and m-MEP neurophysiological monitoring in patients with preoperative motor deficits in immediate and late postoperative period.

BACKGROUND: Presence of preoperative motor deficits in patients poses a distinct challenge in monitoring the integrity of corticospinal tracts during spinal surgeries. The inconsistency of the motor-evoked potentials is such patients, limits its clinical utility. D-wave is a robust but less utilized technique for corticospinal tract monitoring. The comparative clinical value of these two techniques has not been evaluated in the patients with preoperative deficits. OBJECTIVES: The objective of the study was to compare the predictive utility of myogenic Motor Evoked Potentials (m-MEP) and D-wave in terms of recordability and their sensitivity and specificity in predicting transient and permanent new motor deficits. MATERIALS AND METHODS: Thirty-one patients with preoperative motor deficit scheduled to undergo spinal surgery were included in the study. Intraoperative m-MEP and D-wave changes were identified and correlated with postoperative neurology in the immediate postoperative period and at the time of discharge. RESULTS: The mean preoperative motor power of the patient pool in left and right lower limb was 2.97 ± 1.56 and 3.32 ± 1.49, respectively. The recordability of m-MEPs and D-wave was observed to be 79.4% and 100%, respectively. The m-MEP predicted the motor deterioration in immediate postoperative period with 100% sensitivity and 80% specificity, while D-wave had 14% sensitivity and 100% specificity. At the time of discharge, m-MEPs' specificity reduced to 61%, while D-wave demonstrated 100% specificity. CONCLUSIONS: D-wave has a better recordability than m-MEPs in neurologically compromised patients. D-wave predicts development of long-term deficits with 100% specificity, while m-MEPs have a high sensitivity for transient neurological deficit. A combination of D-wave and m-MEP is recommended for monitoring the integrity of the corticospinal tract in patients with preoperative motor deficits.

The Cardiovascular Variability during Transient 6° Head Down Tilt and Slow Breathing in Yoga Experienced Healthy Individuals.

OBJECTIVE: The intervention of yoga has been shown to improve autonomic conditioning in humans and better adaptability to orthostatic challenges. Similarly, slow breathing at 0.1 Hz akin to pranayama also increases baroreflex sensitivity (BRS). Hence, we intended to investigate whether yoga practitioners have different autonomic responses at rest,during slow deep breathingas well as during 6° head down tilt (HDT) compared to naive group individuals. AIM: The aim of the study was to evaluate the acute effects of slow breathing on cardiovascular variability during HDT in yoga practitioners compared to yoga-naïve individuals. SETTINGS AND DESIGN: This was a comparative study with repeated measures design conducted in Autonomic Function Test lab of the Department of Physiology, All India Institute of Medical Sciences, New Delhi, India. MATERIALS AND METHODS: Time domain and frequency domain parameters of heart rate variability, blood pressure variability (BPV), and BRS were evaluated during 6° HDT and slow breathing at 0.1 Hz on forty yoga-naïve individuals and forty yoga practitioners with an average age of 31.08 ± 7.31 years and 29.93 ± 7.57 years, respectively. All of the participants were healthy. STATISTICAL ANALYSIS USED: General Linear Mixed Model ANOVA was applied with yoga experience as a between-group factor in repeated measures. Independent sample t-test was applied for between group comparison of respiratory rate, demographic, and anthropometric data. P <0.05 is considered statistically significant. RESULTS: Between-group comparison during HDT with spontaneous breathing has shown a significantly lower heart rate (P = 0.004) with higher RR interval (RRI) (P = 0.002) and pNN50% (P = 0.019) in yoga practitioners. The sequence BRS (P < 0.0001) and α low frequency (LF) of spectral BRS (P = 0.035) were also significantly higher in the yoga group compared to the naïve group. Similarly, during HDT with slow breathing, the heart rate was lower (P = 0.01); with higher RRI (P = 0.009); pNN50% (P = 0.048). Standard deviation of successive RR interval difference of systolic BPV was lower (P = 0.024) with higher sequence BRS (P = 0.001) and α LF of spectral BRS (P = 0.002) in yoga group than naïve group. CONCLUSION: The yoga experienced individuals exhibit higher resting parasympathetic activity, lower systolic BPV, and higher BRS than naïve to yoga individuals. It is inferred from the findings that yoga practitioners were better adapted to transient cephalad fluid shift that happens during 6° HDT. Furthermore, acute slow breathing during 6° HDT reduced the systolic blood pressure in all the participants suggesting the beneficial role of slow breathing during exposure to extreme conditions such as microgravity which might help in the prevention of adverse effects of cephalad fluid shift during long-term weightlessness and maintain the astronaut health. Future mechanistic studies with active yoga intervention are necessary to understand the adaptive mechanisms involving central and vascular modulations contributing to either attenuation or accentuation of the cardiovagal baroreflex during HDT and slow breathing in healthy individuals.

Effect of structured training in improving the ergonomic stress in laparoscopic surgery among general surgery residents.

BACKGROUND: Minimal access surgery has fast become the standard of care for many operative procedures, but is associated with lot of ergonomic stress to the surgeons performing these procedures, which may result in reduction in surgeon's performance and work capacity. In this study, we evaluated the impact of structured training program in improving the ergonomic stress in trainee laparoscopic surgeons. METHODS: Laparoscopic surgeons were divided in 2 groups: trainee surgeons (ten) and expert surgeons (three). Baseline surface electromyography (sEMG) data were collected from bilateral deltoid, biceps brachii, forearm extensors, and pronator teres during a predefined suturing task on Tuebingen trainer with integrated porcine organs in both the groups. Trainee surgeons underwent 20 h of laparoscopic intra-corporeal suturing training and surface electromyography data were recorded at the end of training again and compared with baseline. RESULTS: Experts were found to have lower muscle activation (p < 0.05) and muscle work (p < 0.05) and better bimanual dexterity than the trainee surgeons at baseline. After training, the trainee surgeons showed significant improvement (p = 0.01), but still did not reach the values of the expert surgeons (p = 0.01). Right deltoid and pronator teres muscles were found to have maximal activity while performing intra-corporeal suturing. CONCLUSION: Structured and focused training outside operation theater can significantly reduce unnecessary muscle activation of trainee laparoscopic surgeons and better dexterity leading on to lesser ergonomic stress and thus possibly may reduce the risk of development of future musculo-skeletal disorders.

Longitudinal electromyographic changes in masseter and anterior temporalis muscle before and after temporomandibular joint arthroplasty in ankylosis patients.

PURPOSE: The literature lacks evidence about activity of masseter and anterior temporalis muscles in temporomandibular joint ankylosis (TMJA) patients. The purpose of this study was to evaluate longitudinal electromyography (EMG) changes in masseter and anterior temporalis muscle before and after gap arthroplasty in unilateral TMJA patients. Specific aim was to investigate the EMG activity restoration to the level of non-ankylosed side after arthroplasty. METHODS: The investigator implemented a prospective longitudinal study amongst TMJA patients treated with gap arthroplasty. EMG of masseter and anterior temporalis were recorded bilaterally on ankylosed and non-ankylosed side. EMG signals of masseter and anterior temporalis were recorded preoperatively and 1 week, 3 month and 6 month postoperatively at rest and at maximum voluntary clench (MVC). RESULTS: The study sample was composed of 16 (male:female = 1:1.28) unilateral TMJA patients. The mean duration of ankylosis was 3.25 ± 1.18 years. The difference in EMG root-mean-square (RMS) values of ankylosed side when compared to the preoperative values of non-ankylosed side was found to be statistically significant (p < 0.001) preoperatively, 1 week and 3 month postoperatively, while it was statistically not significant (p > 0.99) at 6-month postoperatively. CONCLUSION: The present study concludes that the TMJA patients have hyperactivity of masseter and anterior temporalis muscle. Restoring the function causes the muscle activity to progress to the values of normal side. EMG activity as measured on follow-up may be one of the predicting factor for re-ankylosis.

Acute sleep deprivation elevates brain and body temperature in rats.

Available sleep deprivation studies lack data on simultaneous changes in hypothalamic, cortical and body temperature during sleep deprivation and recovery. Ten adult male Wistar rats chronically implanted with electroencephalogram, electro-oculogram and electromyogram electrodes for recording sleep were used in this study. Hypothalamic and cortical temperatures were measured by pre-implanted thermocouples. A radio transmitter (TA10TAF-40, DSI USA) was implanted intraperitoneally to measure body temperature. All the temperatures were measured simultaneously at 15-s intervals during baseline conditions, sleep deprivation and recovery sleep. Sleep deprivation was carried out for 24 hr by the gentle handling method; however, sleep and temperature were only recorded during the first 12 hr of deprivation. During sleep deprivation the body, hypothalamic and cortical temperatures increased significantly as compared to baseline. During recovery sleep, body and cortical temperature recovered earlier than the hypothalamic temperature. Hypothalamic temperature remained higher than the baseline values throughout 12 hr of recovery sleep. In the recovery sleep, cortical temperature decreased immediately and reached near baseline by 4 hr. We observed a quicker return of cortical temperature towards control temperature during recovery sleep compared with hypothalamic and body temperature. The results of the present study show that acute sleep deprivation results in a rise in both cortical and hypothalamic temperature, along with body temperature. A rise in cortical temperature may be a contributing factor for cognitive dysfunction resulting from sleep deprivation.

Effect of Disease Severity on Respiratory Impedance in Parkinson's Disease.

BACKGROUND: Parkinson's disease (PD) is a progressive neurodegenerative disorder. PD has been traditionally perceived as a motor disorder. However, it is frequently associated with pulmonary dysfunction which has been assessed by Spirometry, an effort-dependent technique. PURPOSE: To evaluate in patients with PD the effect of disease severity on respiratory impedance using Impulse Oscillometry (IOS) and to correlate with Spirometry. METHODS: The study was conducted on 30 patients diagnosed with PD. Pulmonary function was assessed by IOS and spirometer. IOS is an effort-independent technique that uses sound waves of different frequencies to measure airway resistance. Spirometer measures the lung volume and generates flow-volume and volume-time relationship. RESULTS: The mean age of patients was 60.1±9.45. Resistance at 5 Hz (R5) was found to be negatively correlated with forced expiratory volume in the first second of the FVC manoeuver (FEV1) (r = -0.628, P = .002), FEV1/FVC (forced vital capacity) (r = -0.487, P = .025), and PEF (r = -0.599, P = .004), and resistance at 20 Hz (R20) with FEV1 (r = -0.474,P = .029) and PEF (r = -0.522, P = .015). There was significant increase in R5 (0.32(0.36-0.28) vs 0.47(0.60-0.36); P = .04) and R20 (0.25(0.28-0.20) vs 0.30(0.40-0.25); P = .04) in stage II as compared to stage I of Hoehn-Yahr scale. CONCLUSION: IOS might be a promising tool for diagnosis of respiratory dysfunction in addition to Spirometry, especially in cases where patients are not able to perform forced manoeuvers.

Improvement in Angiotensin 1-7 precedes and correlates with improvement in Arterial stiffness and endothelial function following Renin-Angiotensin system inhibition in type 2 diabetes with newly diagnosed hypertension.

BACKGROUND AND AIM: Studies in cell cultures and animal models have revealed the possible pathophysiological factors associated with vascular endothelial dysfunction. However, the same in human subjects has not been clearly established. The current study uses a novel approach to identify the factors associated with endothelial function and arterial function by altering these vascular parameters using Angiotensin-Converting-Enzyme (ACE) inhibition. METHODS: Diabetic patients with newly diagnosed hypertension (n = 60) were recruited for the study. Flow-mediated-dilation (FMD), carotid-femoral (cf), carotid-radial (cr) Pulse-wave-velocity (PWV), Augmentation-Index, Carotid-Intima-Media-Thickness (CIMT), serum levels of Renin, Angiotensin II (AngII), Angiotensin-Converting-Enzyme2 (ACE2), Angiotensin1-7 (Ang1-7), E-selectin, Vascular-Cell-Adhesion-Molecule-1 (VCAM-1), Highly-sensitive-C-Reactive-Protein (hsCRP) and Interleukin-10 were measured at baseline (V1), after 1 week (V2) and 3 months (V3) of ACE inhibition in patients of diabetes with newly diagnosed hypertension. The amplitude of change after 1 week (V2-V1) and 3 months (V3-V1) for the clinical and various parameters were correlated with the change in endothelial function and arterial stiffness. RESULTS: Carotid radial-PWVV2-V1 (p = 0.001) and Ang1-7V2-V1 (p = 0.01) emerged as independent predictors of FMDV2-V1. ReninV2-V1 and VCAM-1V2-V1 independently predicted E-selectinV2-V1 [(p = 0.01) and (p = 0.001), respectively]. ACE 2V2-V1 was the only independent predictor of cf-PWVV2-V1. The same parameters remained as independent predictors of the respective vascular factors after 3 months of ACE inhibition. CONCLUSION: The study highlights the role of AngII/Ang1-7 balance in alteration of endothelial function and central arterial stiffness in humans in addition to identifying the interrelationship between the renin-angiotensin-aldosterone-system components and clinically ascertainable parameters.

Cortex senses environmental temperature earlier than the hypothalamus in awake rats.

Simultaneous and direct recording of temperature from the body, hypothalamus, and cortex in animals exposed to acute thermal challenges lack evidence. This study was conducted to assess the usual concept, that brain temperature is rather stable when animals are exposed to different ambient temperatures. In this study, we report the characteristic changes in the body, hypothalamic, and cortical temperature, when the rats were acutely exposed to cold (6 °C) and hot (36 °C) ambient temperature. The results of our study show that the body temperature is robustly regulated while hypothalamic and cortical temperatures vary on challenges to ambient cold (6 °C) and warm (36 °C) exposure in awake rats. The onset of response was observed quickest in the cortex, indicating that the cortical thermal sensing may relay intracranial thermal input to the hypothalamus for the regulation of body temperature within narrow limits. The present findings contradict earlier evidence, which stated that the brain does not participate in thermal sensing.

Is There a Difference in Autonomic Dysfunction Between Multiple System Atrophy Subtypes?

BACKGROUND: Autonomic dysfunction forms the diagnostic cornerstone in MSA. Data are limited on autonomic dysfunction differences between the two subtypes, MSA-C and MSA-P. OBJECTIVES: To assess autonomic dysfunction in MSA subtypes and Parkinson's disease (PD) and compare it to healthy controls. METHODS: We conducted a cross-sectional study. A validated questionnaire (Scales for Outcomes in Parkinson's Disease-Autonomic Dysfunction; SCOPA-AUT) was used for symptom screening. Cardiovascular autonomic testing included deep breathing (change in heart rate, E: I ratio), Valsalva ratio, diastolic blood pressure (BP) rise (hand grip, cold pressor), and postural (tilt, 30:15 ratio) tests. Disease severity was assessed by the Unified MSA Rating Scale (UMSARS), H & Y stage, and International Parkinson and Movement Disorder Society Unified Parkinson's Disease Rating scale part III. RESULTS: MSA-P (48 subjects; age, 63.6 ± 9.7 years; UMSARS, 45.0 ± 16.5), MSA-C (52 subjects; age, 58.0 ± 8.1 years; UMSARS, 44.0 ± 12.8), PD (50 subjects; age, 57.6 ± 6.7 years), and healthy controls (50 subjects; age, 58.0 ± 8.0 years) were enrolled. MSA patients had higher SCOPA-AUT scores in gastrointestinal, urinary, cardiovascular, and sexual domains than controls and in gastrointestinal, urinary, and cardiovascular domains compared to PD. The two MSA subtypes did not differ in autonomic dysfunction. Heart-rate change on tilt and deep breathing, and diastolic BP rise on cold pressor test, differed significantly between MSA and PD patients. CONCLUSIONS: Autonomic dysfunction symptomatology and cardiovascular autonomic tests were similar between MSA-P and MSA-C patients. Autonomic symptoms were more prominent in MSA than PD. Emphasis on these domains may improve likelihood of accurate clinical diagnosis of MSA at earlier stages.

Severe Cardiac Dysautonomia and Sudden Death in a Patient Presenting with Anginal Symptoms in Absence of Cardiovascular and Other Diseases: A Case Report.

Angina is a type of chest pain, experienced by patients with ischemic heart diseases. Cardiac autonomic modulation as assessed by heart rate variability and baroreflex sensitivity is found reduced in ischemic heart disease patients. Marked reduction in heart rate variability and baroreflex sensitivity in ischemic heart disease patients is found associated with sudden cardiac death. We report a case of a 35-year-old man who presented with angina for the last few months. Thorough investigations showed no evidence of any cardiac or other systemic diseases. However, his cardiovascular autonomic modulation (as assessed by heart rate variability) and spontaneous baroreflex sensitivity were markedly reduced. The patient had sudden death within 6 months of follow-up. Reportedly, no other specific abnormalities were found before death. This case report suggests that patients presenting with typical chest pain as angina may have severe dysautonomia and risk of sudden death even in the absence of cardiovascular or any other known end-organ diseases.

Sequential analysis of heart rate variability, blood pressure variability and baroreflex sensitivity in healthy pregnancy.

OBJECTIVE: The aim of this study was to demonstrate the temporal profile of changes in heart rate variability (HRV), blood pressure variability (BPV), and cardiac baroreflex sensitivity (BRS) during the course of a healthy pregnancy. MATERIALS AND METHODS: This was a longitudinal study during which autonomic variability parameters (HRV, BPV, BRS) were assessed in 66 pregnant women at 11-13, 20-22 and 30-32 weeks of gestation. A lead II electrocardiogram tracing and beat-to-beat blood pressure were recorded with the subject breathing spontaneously in the supine position. Changes in the parameters were analyzed using repeated measures analysis of variance. RESULTS: Overall HRV (SDNN; standard deviation of all NN intervals) was found to decrease significantly over the course of pregnancy (p < 0.05). Similarly, indices which represent the parasympathetic component of these variables (SDSD [standard deviation of differences between adjacent NN intervals]; pNN50 [NN50 count {number of pairs of adjacent NN intervals differing by more than 50 ms} divided by the total number of all NN intervals]; high-frequency [HF] power) were also found to decrease significantly from the first to third trimester of pregnancy (p < 0.05). Low-frequency (LF) power increased over the course of pregnancy (p < 0.05). The LF/HF ratio increased significantly from first to third trimester of pregnancy (median: 0.66 [first trimester] vs.1.02 [second] vs. 0.91 [third]; p < 0.05) Overall BPV increased during the course of pregnancy, with a significant rise in the HF component of BPV and a significant fall in the LF component of BPV with advancing gestation (p < 0.05). BRS decreased over the course of pregnancy (median: 16.31, interquartile range [IQR] 11.04-23.13 [first trimester] vs. 11.42, IQR 8.54-19.52 [second] vs. 8.84, IQR 7.15-12.45 [third] ms/mmHg; p < 0.05). CONCLUSION: Pregnancy is associated with decreased vagal and increased sympathetic modulation of cardiac autonomic tone with advancing gestation, together with increased BPV. The reduction in cardiac BRS may play a role in increasing BPV and decreasing HRV over the course of pregnancy.

Effect of slow breathing on autonomic tone & baroreflex sensitivity in yoga practitioners.

BACKGROUND & OBJECTIVES: Slow breathing increases parasympathetic activity and baroreflex sensitivity (BRS) in healthy individuals, also similarly observed in yoga practitioners. Pranayama which is an important component of yoga when practiced at a slow pace was at a respiratory frequency of around 0.1 Hz (6 breaths/min). Therefore, it was hypothesized that yoga practitioners might have adapted to slow breathing. This study was aimed to decipher the role of yoga on cardiovascular variability during slow breathing (0.1 Hz) in yoga practitioners. METHODS: A cross-sectional study was undertaken in naïve-to-yoga individuals (n=40) and yoga practitioners (n=40) with an average age of 31.08 ± 7.31 and 29.93 ± 7.57 yr, respectively. The analysis of heart rate variability, blood pressure variability (BPV) and BRS during spontaneous and slow breathing was compared between the two groups. RESULTS: During slow breathing, the heart rate (P<0.01) was lower, respiratory rate interval (P<0.05) and pNN50 per cent (P=0.01) were higher, mean systolic BP (SBP) (P<0.05) and SDSD (Standard deviation of successive beat to beat systolic blood pressure differences) (P<0.01) of SBP variability were lower with sequence BRS (P<0.001) and α low frequency (P<0.01) and α high frequency (P<0.001) of spectral BRS were higher in yoga practitioners. INTERPRETATION & CONCLUSIONS: The present study indicated higher parasympathetic activity and BRS with lower SBP variability at rest and during slow breathing in yoga practitioners compared to naive group. Findings indicate that the short-term practice of slow breathing complements the augmented parasympathetic activity and BRS in the yoga group.

Sequential profile of endothelial functions and arterial stiffness in preeclampsia during the course of pregnancy.

OBJECTIVE: To evaluate the temporal profile of arterial functions during the course of pregnancy and also to determine the predictive accuracy of vascular function indices in development of preeclampsia (PE). STUDY DESIGN: Longitudinal study, two hundred and eight women participated in the study and vascular functions were assessed at 11-13, 20-22 and 30-32 weeks of gestation. MAIN OUTCOME MEASURES: Flow mediated dilatation (FMD), augmentation index (AIx), pulse wave velocity (PWV). RESULTS: Out of 208 women, 13 women developed PE while 70 remained healthy pregnant (HP). In HP women, normalized FMD decreased gradually from 11 to 13 weeks to 30-32 weeks of gestation (p < 0.05). While in PE, Normalized FMD decreased from 11 to 13 to 20-22 weeks of gestation (p < 0.05) and was significantly lower in PE than HP group at 20-22 weeks of gestation (p < 0.05). AIx showed a mid trimester drop in HP group (p < 0.05) while demonstrated a rising trend in PE. Both AIx and PWV were significantly higher in PE than HP group during the course of pregnancy (p < 0.05). AIx demonstrated good sensitivity and specificity at both 11-13 and 20-22 weeks of gestation. Carotid femoral PWV showed an area under curve (AUC) of 78.18% and 69.75% at 11-13 and 20-22 weeks of gestation respectively. Carotid radial PWV showed good accuracy at 20-22 weeks (AUC-77.58%) of gestation. CONCLUSIONS: Compromised arterial functions precede the onset of PE. AIx and carotid femoral PWV constitute potential predictive marker in early pregnancy for later development of PE.

Polyneuropathy in Critically Ill Mechanically Ventilated Children: Experience From a Tertiary Care Hospital in North India.

OBJECTIVES: To determine the prevalence of critical illness polyneuropathy and its risk factors in critically ill children mechanically ventilated for 7 days or more. DESIGN: Observational cohort study. SETTING: PICU of a tertiary care hospital from North India. PATIENTS: Children 1-15 years old admitted in PICU from June 2016 to September 2017, mechanically ventilated for 7 days or more, excluding those with diagnosed neuromuscular disease, stroke, or spinal pathology. INTERVENTION: Demographic details, diagnosis, treatment details, and anthropometry at admission and enrolment were recorded. Nerve conduction studies were performed after enrolment and repeated a week later, if the child was still in PICU. Medical Research Council scoring for muscle strength was performed in survivors. Risk factors including Pediatric Index of Mortality-2 score, sepsis, multiple organ dysfunction, hypoalbuminemia, use of steroids, neuromuscular-blocking agents, and vasopressors were recorded. Samples for the level of micronutrients (copper, zinc, folate, and vitamin B12) were collected at the time of enrolling the child and at the time of discharge. MEASUREMENTS AND MAIN RESULTS: Thirty-two children were enrolled, of whom 29 had features of critical illness polyneuropathy on evaluation at day 8 of mechanical ventilation (prevalence, 90.6% [95% CI, 80.5-100%]). The polyneuropathy was axonal in 26 (81.2%), mixed in one patient (3.1%), and uncharacterized in two (6.2%). Sepsis and multiple organ dysfunction were present in 31 subjects (96.9%). No risk factors for critical illness polyneuropathy could be identified although the study was not sufficiently powered to do so. The difference between serum micronutrient levels (copper, zinc, folate, and vitamin B12) between patients who developed polyneuropathy, and those who did not, was statistically insignificant. CONCLUSIONS: We observed a high prevalence of critical illness polyneuropathy in children in PICU, mechanically ventilated for 7 days or more; almost all of whom had underlying sepsis.