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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.
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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.
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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.
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COVID-19 , Rigidez Vascular , Feminino , Humanos , Masculino , Lactente , Pré-Escolar , Barorreflexo , Análise de Onda de Pulso , Artérias Carótidas , Pressão Sanguínea , Frequência CardíacaRESUMO
OBJECTIVES: The aim of the present study was to evaluate the integrity of autonomic nervous system in spinocerebellar ataxia (SCA) type 1 and 2 patients using battery of autonomic function tests and their comprehensive scoring using composite autonomic severity score (CASS). MATERIAL AND METHODS: Battery of autonomic function test comprising of cardiovascular (baroreflex dependent and non-baroreflex dependent) and sudomotor functions were assessed in age and gender-matched SCA1 (n = 31), SCA2 (n = 40) patients along with healthy controls (n = 40). To assess the grade of autonomic abnormalities, the composite autonomic severity score (CASS) was computed using the results of the standard autonomic function tests. RESULTS: We found reduction in baroreflex dependent autonomic reactivity parameters predominantly a significant fall of systolic blood pressure (<0.001) and lower 30:15 ratio (<0.001) during head up tilt in both the SCA1 and SCA2 as compared to controls. On sudomotor assessment, distal leg latency of sweat response was prolonged in SCA1 than SCA2 patients. Moderate generalized autonomic failure was commonly found amongst SCA1 (80.65%) and SCA2 (85%) patients. Severe autonomic failure was found to be more in SCA1 (6.45%) than SCA2 (2.50%) patients. CONCLUSIONS: Cardiovascular autonomic function assessment in SCA1 and SCA2 patients revealed a significant impairment in the baroreflex loop integrity. Severity scoring using CASS suggests the existence of moderate autonomic failure in majority of both SCA1 and SCA2 patients.
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Ataxias Espinocerebelares , Humanos , Ataxias Espinocerebelares/diagnóstico , Sistema Nervoso Autônomo , Pressão SanguíneaRESUMO
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.
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Barorreflexo , Vasoconstrição , Humanos , Barorreflexo/fisiologia , Vasoconstrição/fisiologia , Hipovolemia , Pressão Sanguínea/fisiologia , Resistência Vascular , Frequência Cardíaca/fisiologiaRESUMO
Retrograde flow in endothelial cell cultures has been shown to induce a pro-atherogenic phenotype. Despite its potential role as a pathophysiological link between cardiovascular risk factors and atherosclerotic disease, resting retrograde flows between patients with cardiovascular disease and healthy subjects have not been compared. Further, the vascular characteristics governing retrograde flow in human arteries have not been systematically investigated. Association of central and peripheral vascular characteristics with retrograde flow profile was investigated in 32 healthy subjects and 47 patients with ischemic heart disease. Endothelial dysfunction was assessed by brachial ultrasound-based calculation of flow-mediated dilation (FMD) and sub-clinical atherosclerosis was estimated from carotid-intima media thickness (CIMT). Retrograde blood flow velocity (RBFV) and shear rate were comparable between the two groups (RBFV 1.82(0.97-3.32) vs 1.78(1.24-2.65) cm/s p = 0.79). Augmentation index was a significant determinant of retrograde flow in both patients and healthy subjects. Carotid artery incremental elastic modulus was an independent determinant of retrograde flow patterns in healthy subjects while ejection fraction, cf/cr PWV ratio and forearm vascular conductance emerged as independent determinants in patients. Retrograde flow patterns were also associated with FMD (RBFV r = -0.43, p = 0.004) and CIMT (r = 0.30, p = 0.041) in patients. The results of the study suggest a difference in the determinants of retrograde flow in patients and healthy subjects, with central arterial stiffness being a major contributor in healthy subjects while interaction between central, peripheral, and cardio-arterial factors influence retrograde flow in patients with ischemic heart disease.
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Aterosclerose , Isquemia Miocárdica , Rigidez Vascular , Humanos , Artéria Braquial , Espessura Intima-Media Carotídea , Voluntários Saudáveis , Isquemia Miocárdica/diagnóstico , Endotélio Vascular , VasodilataçãoRESUMO
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).
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Reabilitação Cardíaca , Infarto do Miocárdio , Yoga , Humanos , Pressão Sanguínea/fisiologia , Barorreflexo/fisiologia , Infarto do Miocárdio/reabilitação , Frequência CardíacaRESUMO
Background: Parkinson's disease (PD) is a neurodegenerative disease perceived as a motor disorder. It is most commonly associated with autonomic dysfunction, affecting multiple systems. This altered autonomic control might be reflected by a parallel change in the airway caliber of these patients. Aim: To correlate the pulmonary impairment in patients with Parkinson's disease with the underlying dysautonomia. Materials and Methods: A total of 30 patients with Parkinson's disease participated in the study. Heart rate (HR) variability was recorded for 5 min to assess the autonomic dysfunction, followed by impulse oscillometry (IOS) and spirometry. IOS being an effort independent technique uses sound waves at different frequencies (5-25 Hz) to measure the airway impedance. Results: There was a significant decrease in SDSD (6.60 (10.18-6.01) vs. 12.22 (13.95-11.30); P = 0.04), RMSSD (6.59 (10.17-5.50) vs. 12.20 (13.93-11.28); P = 0.04), and total power (315.8 (506.3-120.7) vs. 771.3 (799.0-643.6); P = 0.04) in stage II as compared to stage I. Resistance at 20 Hz (R20) was found to be positively correlated with SDSD (r = 0.40, P = 0.04), RMSSD (r = 0.40, P = 0.04), and HF (r = 0.41, P = 0.03). Conclusion: Amongst the PD population, any changes in the parasympathetic component (responsible for bronchoconstriction) due to the underlying dysautonomia might be reflected as increased airway resistance in the pulmonary system.
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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.
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Sistema Nervoso Autônomo , Hipovolemia , Eletrocardiografia , Frequência Cardíaca , Hemorragia , Humanos , Hipovolemia/diagnóstico , MasculinoRESUMO
Craniopagus conjoined twins are extremely rare, reported 1 in 2.5 million live births. To date, 62 separation attempts in 69 well-documented cases of craniopagus twins have been made. Of these, 34 were performed in a single-stage approach, and 28 were attempted in a multistage approach. One or both twins died of massive intraoperative blood loss and cardiac arrest in 14 cases. We report our surgical experience with conjoined craniopagus twins (JB) with type III total vertical joining and shared circumferential/circular sinus with left-sided dominance. A brief review of the literature is also provided. In our twins, the meticulous preoperative study and planning by the multidisciplinary team consisting of 125-member, first-staged surgical separation consisted of creation of venous conduit to bypass part of shared circumferential sinus and partial hemispheric disconnection. Six weeks later, twin J manifested acute cardiac overload because of one-way fistula development from blocked venous bypass graft necessitating emergency final separation surgery. Unique perioperative issues were abnormal anatomy, hemodynamic sequelae from one-way fistula development after venous bypass graft thrombosis, cardiac arrest after massive venous air embolism requiring prolonged cardiopulmonary resuscitation, and return of spontaneous circulation at 15 minutes immediately after separation. This is the first Indian craniopagus separation surgery in a complex total vertical craniopagus twin reported by a single-center multidisciplinary team. Both twins could be sent home, but one remained severely handicapped. Adequate perioperative planning and multidisciplinary team approach are vital in craniopagus twin separation surgeries.
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Fístula , Parada Cardíaca , Procedimentos de Cirurgia Plástica , Gêmeos Unidos , Cavidades Cranianas/cirurgia , Parada Cardíaca/cirurgia , Humanos , Gêmeos Unidos/cirurgiaRESUMO
INTRODUCTION: Genetically defined spinocerebellar ataxia (SCA) type 1 and 2 patients have differential clinical profile along with probable distinctive cortical and subcortical neurodegeneration. We compared the degree of brain atrophy in the two subtypes with their phenotypic and genotypic parameters. METHODS: MRI was performed using a 3T scanner (Philips, Achieva) to obtain 3D T1-weighted scans of the whole brain and analyzed by FreeSurfer (version 5.3 and 6 dev.) software. Genetically proven SCA1 (n = 18) and SCA2 (n = 25) patients with age-matched healthy controls (n = 8) were recruited. Clinical severity was assessed by the International Cooperative Ataxia Rating Scale (ICARS). To know the differential pattern of atrophy, the groups were compared using ANOVA/Kruskal-Wallis test and followed by correlation analysis with multiple corrections. Further, machine learning-based classification of SCA subtypes was carried out. RESULT: We found (i) bilateral frontal, parietal, temporal, and occipital atrophy in SCA1 and SCA2 patients; (ii) reduced volume of cerebellum, regions of brain stem, basal ganglia along with the certain subcortical areas such as hippocampus, amygdala, thalamus, diencephalon, and corpus callosum in SCA1 and SCA2 subtypes; (iii) higher subcortical atrophy SCA2 than SCA1 (iv) correlation between brain atrophy and disease attributes; (v) differential predictive pattern of two SCA subtypes using machine learning approach. CONCLUSION: The present study suggests that SCA1 and SCA2 do not differ in cortical thinning while a characteristic pattern of subcortical atrophy SCA2 > SCA1 is observed along with correlation of brain atrophy and disease attributes. This may provide the diagnostic guidance of MRI to SCA subtypes and differential therapies.
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Ataxias Espinocerebelares , Atrofia/patologia , Encéfalo/diagnóstico por imagem , Cerebelo/patologia , Humanos , Imageamento por Ressonância Magnética , Ataxias Espinocerebelares/diagnóstico por imagemRESUMO
OBJECTIVE: Spinocerebellar ataxia (SCA) is a neurodegenerative disorder in which, autonomic dysfunction is a common manifestation. Brain area atrophy also involves the areas comprising central autonomic network (CAN) in SCA. Structural atrophy of CAN and autonomic dysfunction should go hand in hand. But this important relationship has not been studied to date. Therefore, using SCA as a disease model, the present study has been designed to explore the plausible correlations between the brain areas of CAN and clinical autonomic function modalities in SCA patients. MATERIALS AND METHODS: 3D T1-weighted scans were acquired on 3T MRI, analyzed by FreeSurfer software in genetically confirmed forty-nine SCA patients (SCA1 = 18, SCA2 = 25 and SCA3 = 6). Heart rate variability (HRV), blood pressure variability (BPV), baroreflex sensitivity (BRS), and autonomic reactivity tests were used for evaluation of autonomic nervous system. Additionally, autonomic dysfunction scoring was done using composite autonomic severity score (CASS). RESULTS: On correlation analysis, the study showed the association of atrophic cortical and subcortical brain areas (predominantly prefrontal cortex, bilateral middle temporal, left cuneus, left lingual and left caudate) with altered clinical autonomic function parameters in SCA patients. These areas were primarily comprised of sympathetic and parasympathetic brain areas of CAN. One of the key brain areas of CAN - left cuneus was found to be associated with both HRV (r = 0.295, p = 0.040) and BRS (r = 0.326, p = 0.022). CONCLUSION: A characteristic pattern of association between particular brain areas of CAN and clinical autonomic function parameters was observed in SCA patients.
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Ataxias Espinocerebelares , Atrofia/patologia , Sistema Nervoso Autônomo , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Humanos , Imageamento por Ressonância Magnética , Ataxias Espinocerebelares/diagnóstico por imagem , Ataxias Espinocerebelares/patologiaRESUMO
Yoga has been shown to improve autonomic conditioning in humans, as evidenced by the enhancement of parasym-pathetic activity and baroreflex sensitivity. Therefore, we hypothesized that the experience of yoga may result in adaptation to acute hemodynamic changes. To decipher the long-term effects of yoga on cardiovascular variability, yoga practitioners were compared to yoga-naïve subjects during exposure to -40 mm Hg lower-body negative pressure (LBNP). A comparative study was conducted on 40 yoganaïve subjects and 40 yoga practitioners with an average age of 31.08 ± 7.31 years and 29.93 ± 7.57 years, respectively. Heart rate variability, blood pressure variability, baroreflex sensitivity, and correlation between systolic blood pressure and RR interval were evaluated at rest and during LBNP. In yoga practitioners, the heart rate was lower in supine rest (p = 0.011) and during LBNP (p = 0.043); the pNN50 measure of heart rate variability was higher in supine rest (p = 0.011) and during LBNP (p = 0.034). The yoga practitioners' standard deviation of successive beat-to-beat blood pressure intervals of systolic blood pressure variability was lower in supine rest (p = 0.034) and during LBNP (p = 0.007), with higher sequence baroreflex sensitivity (p = 0.019) and ~ high-frequency baroreflex sensitivity. Mean systolic blood pressure and RR interval were inversely correlated in the yoga group (r = -0.317, p = 0.049). The yoga practitioners exhibited higher parasympathetic activity and baroreflex sensitivity with lower systolic blood pressure variability, indicating better adaptability to LBNP compared to the yoga-naïve group. Our findings indicate that the yoga module was helpful in conditions of hypovolemia in healthy subjects; it is proposed to be beneficial in clinical conditions associated with sympathetic dominance, impaired barore-flex sensitivity, and orthostatic intolerance.
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Barorreflexo , Yoga , Adulto , Pressão Sanguínea , Frequência Cardíaca , Humanos , Pressão Negativa da Região Corporal Inferior , Adulto JovemRESUMO
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.
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INTRODUCTION: The relationship between low flow-mediated constriction (LFMC), a new proposed measure of endothelial function, with cardiovascular disease severity and its hypothesized stimulus, that is, low flow, has not been comprehensively evaluated. The study evaluated association between change in brachial artery diameter during constriction with severity of myocardial perfusion defect (PD) and alterations in different components of flow profile. METHODS: Brachial artery responses to occlusion were assessed in 91 patients and 30 healthy subjects. Change in anterograde and retrograde blood flow velocities (delta anterograde blood flow velocity and retrograde blood flow velocity), anterograde shear rate and retrograde shear rate (delta ASR and RSR, respectively), and oscillatory shear index (delta) during forearm occlusion at 50 mm Hg above systolic pressure, from baseline was calculated. Myocardial perfusion was evaluated in patients using exercise single positron emission computed tomography and % myocardial PD was calculated from summed stress score. RESULTS: LFMC emerged as independent predictor of defect severity after correcting for age and gender (p = 0.014). Sixty-seven patients (73.6%) and 15 healthy subjects (50%) showed constriction during occlusion. In stepwise backward regression analysis, RSR contributed 35.5% and ASR contributed 20.1% of the total 63.9% variability in artery diameter during occlusion. CONCLUSION: The results suggest that LFMC is independently associated with myocardial perfusion severity and is "mediated" by an altered flow profile during occlusion.
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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.
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The most common cause of mortality in chronic kidney disease patients is cardiovascular events. Cardiovascular autonomic dysfunction is likely to contribute high incidence of cardiovascular mortality, and in addition to adrenergic overdrive in these patients, there is the presence of impaired reflex control of both sympathetic and parasympathetic outflow to the heart and vasculature. Very few studies are available which show that renal transplantation (RT) improves the baroreflex function along with improvement in cardiovascular variability parameters. This prospective study was designed for the assessment of the autonomic function, i.e., heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity (BRS) in end-stage renal disease (ESRD) patients before RT and three and six months after RT and to study the effects of RT on cardiac and vascular autonomic tone and on BRS. We studied 81 ESRD patients prospectively slated for RT but only 64 patients (mean age: 33 years) completed both three and six months visits after RT for autonomic function study. Patients were evaluated in detail clinically as well as routine biochemical parameters were done on every three visits. Baroreflex function was quantified by the sequence method. Assessment of short-term HRV and BPV were done using power spectrum analysis of RR intervals and systolic BP by frequency domain analysis. The parameters of HRV after RT showed significant changes in high-frequency domain measures six months post-RT but not in low frequency. HRV in total power was also statistically significant as early as three months postrenal transplant and remained at six months. The favorable effect of RT on decreasing BPV and improving BRS is seen by as early as three months.
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Barorreflexo/fisiologia , Frequência Cardíaca/fisiologia , Falência Renal Crônica/cirurgia , Transplante de Rim , Adulto , Feminino , Humanos , Período Pós-Operatório , Gravidez , Estudos ProspectivosRESUMO
Cardiovascular diseases are an important cause of mortality in end-stage renal disease (ESRD) and increased arterial stiffness and autonomic dysfunction have been proposed to explain part of this excess cardiovascular risk. This prospective study was designed with the aim of noninvasive assessment of the vascular function, i.e., arterial stiffness in the form of pulse wave velocity (PWV) and autonomic function in the form of baroreflex sensitivity (BRS) in ESRD patients before renal transplantation (RT) and three and six months after RT. The study was conducted in 64 patients of ESRD slated for RT in the Department of Nephrology and was being followed up during all three visits (pretransplant, three-, and six-month posttransplant). The period of patient recruitment and data collection lasted for approximately 1½ years. Although PWV did not show a significant change, the change in PWV was negatively correlated with baseline PWV, and it was statistically significant. The BRS after RT had a significant improvement as early as three months. The correlation between change in PWV and change in BRS postrenal transplant was not seen. RT improves BRS, but it is still unknown that it is through amelioration of arterial properties or neural components or/and a relative contribution of both. We suggest that the improvement in BRS postrenal transplant is probably because of the improvement in autonomic neural functions rather than the improvement in compliance of barosensitive regions of large arteries.
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Barorreflexo/fisiologia , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Análise de Onda de Pulso , Rigidez Vascular/fisiologia , Adulto , Feminino , Humanos , Índia , Falência Renal Crônica/diagnóstico , Testes de Função Renal , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Estudos ProspectivosRESUMO
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.
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Temperatura Corporal/fisiologia , Encéfalo/fisiopatologia , Polissonografia/métodos , Privação do Sono/fisiopatologia , Doença Aguda , Animais , Masculino , Ratos , Ratos Wistar , SonoRESUMO
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.