Cardiac autonomic dysfunction in obese subjects

1989 ◽  
Vol 76 (6) ◽  
pp. 567-572 ◽  
Author(s):  
Marco ROSSI ◽  
Giuliano Marti ◽  
Luigi Ricordi ◽  
Gabriele Fornasari ◽  
Giorgio Finardi ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Body Mass Index ◽  
Heart Rate ◽  
Autonomic Dysfunction ◽  
Cross Correlation ◽  
Heart Rate Response ◽  
Valsalva Manoeuvre ◽  
Deep Breathing ◽  
Cardiac Autonomic Dysfunction ◽  
Obese Subjects

1. The prevalence of cardiac autonomic alterations was evaluated in 23 obese subjects with body mass index 37.2 ± 3.03 kg/m2 (mean ± sd), compared with 78 controls with body mass index 22.5 ± 2.6 kg/m2 (P < 0.001). 2. Cardiac autonomic function was assessed by four standard tests (heart rate response to deep breathing and to the Valsalva manoeuvre, systolic blood pressure fall after standing and diastolic pressure rise during handgrip) and by the cross-correlation test, a new method of computerized analysis of respiratory sinus arrhythmia based on spectral analysis of electrocardiographic and respiratory signals. 3. Considering tests indicative of parasympathetic function, only the heart rate response to the deep breathing and the cross-correlation test were significantly lower in the obese than in the control group [deep breathing = 13.95 ± 8.65 beats/min (mean ± sd) vs 24.5 ± 7.65, P < 0.001; cross-correlation 4.28 ± 0.74 units vs 5.14 ± 0.63, P < 0.001]. Deep breathing and/or cross-correlation were abnormal in 10 (43.5%) obese subjects (deep breathing: seven subjects, cross-correlation: eight subjects). No significant difference between groups was found for the response to the Valsalva manoeuvre: the Valsalva ratio was 1.69 ± 0.45 in obese subjects and 1.88 ± 0.33 in controls (P = NS). The Valsalva ratio was abnormal in three obese subjects. 4. No significant differences were found between groups for tests indicative of sympathetic function. The rise in diastolic blood pressure after handgrip was 12.6 ± 6.2 mmHg (1.67 ± 0.82 kPa) in obese subjects and 18.2 ± 4.9 mmHg (2.42 ± 0.65 kPa) in controls (P = NS), and the fall in systolic blood pressure after standing was −6.8 ± 8.6 mmHg (−0.90 ± 1.14 kPa) in obese subjects and −6.9 ± 10.4 mmHg (−0.91 ± 1.38 kPa) in controls (P = NS). The handgrip test was abnormal in four obese subjects, while no obese subject had an abnormal blood pressure response to standing. 5. Our findings suggest a high incidence of cardiac autonomic dysfunction in obese subjects. Since cardiac autonomic alterations have been shown to be involved in the mechanisms of cardiac sudden death, our data suggest a possible role of autonomic dysfunction in the increased risk for sudden death in obesity.

Antidiuretic hormone response to volume depletion in diabetic patients with cardiac autonomic dysfunction

1985 ◽  
Vol 68 (5) ◽  
pp. 545-552 ◽  
Author(s):  
André Grimaldi ◽  
Wojciech Pruszczynski ◽  
Francis Thervet ◽  
Raymond Ardaillou
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Antidiuretic Hormone ◽  
Autonomic Dysfunction ◽  
Heart Rate Response ◽  
Plasma Aldosterone ◽  
Valsalva Manoeuvre ◽  
Diabetic Patients ◽  
Volume Depletion ◽  
Cardiac Autonomic Dysfunction

1. Thirty-three insulin-dependent diabetic patients were separated into two groups from the results of three different tests for cardiac vagal neuropathy: heart rate response to deep breathing, Valsalva manoeuvre and heart rate response to postural change. Seventeen patients were considered as without ('intact’ patients) and 16 as with ('denervated’ patients) cardiac autonomic dysfunction. One patient with a transplanted heart was also studied. 2. Plasma antidiuretic hormone (ADH), plasma aldosterone and plasma renin activity (PRA) were measured immediately before and 60 min after intravenous administration of frusemide and passage from lying to standing. The kinetics of hormonal responses were analysed more precisely (five blood collections) in six patients of each group who were studied again. Heart rate and blood pressure were recorded before each blood collection. 3. Volume depletion estimated from the rise in plasma protein (+ 11.9 and + 12.2% in ‘denervated’ and ‘intact’ patients respectively) and heart rate response (+ 10.6 and + 14.7%) were similar in both groups. Mean blood pressure was unchanged in the ‘intact’ patients whereas it fell in the ‘denervated’ patients (−13.5%). PRA (+ 161.5 and + 231.2% in ‘denervated’ and ‘intact’ patients respectively) and plasma aldosterone (+ 318.2 and 279%) increased in both groups whereas plasma ADH was stimulated only in ‘intact’ patients (+ 55.3%). The failure of ADH to respond significantly to the volume stimulus in ‘denervated’ patients was confirmed by the results of the time-course study. Plasma ADH remained at the same levels in ‘denervated’ patients whereas it increased significantly (+ 82.4%) in ‘intact’ patients. There was no ADH response in the transplanted patient. 4. These results suggest that, in humans, cardiac receptors and vagal pathways play a role in ADH response to volume depletion.

Short- and long-term reproducibility of autonomic measures in supine and standing positions

2004 ◽  
Vol 106 (1) ◽  
pp. 61-66 ◽  
Author(s):  
M. A. KOWALEWSKI ◽  
M. URBAN
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Response ◽  
Blood Pressure Response ◽  
Body Position ◽  
Valsalva Manoeuvre ◽  
Deep Breathing ◽  
Autonomic Nervous ◽  
Short And Long Term

Autonomic nervous tests and heart rate variability (HRV) have been used to assess cardiac autonomic function and to evaluate long-term prognosis. The aim of this study was to evaluate the short- and long-term reproducibility of HRV parameters and autonomic nervous tests according to body position (supine or standing). The study group consisted of 26 healthy subjects. Autonomic nervous tests and HRV were performed twice during the day and the results were averaged. The protocol was then repeated 3 days after each examination and also after 6 and 24 months. Autonomic nervous tests included deep breathing, Valsalva manoeuvre and isometric muscle exercise (handgrip), as well as blood pressure and heart rate in response to standing. ECG recordings were taken for 10 min during spontaneous breathing for HRV analysis. We found that the reproducibility of some parameters of the autonomic nervous test were independent of body position [E/I ratio (heart rate response to deep breathing)], whereas other parameters were dependent on body position (Valsalva manoeuvre and blood pressure response to sustained handgrip). In addition, within-day measurements of those parameters varied from non-reproducible (Valsalva ratio, handgrip and blood pressure response to standing) to moderately reproducible [E/I ratio and 30/15 ratio (heart rate response to standing)]. Among the HRV parameters, we found that total power (TP), low (LF)- and high (HF)-frequency were reproducible not only for measurements made within the same day, but also during short- and long-term observations, and only the LF/HF ratio was dependent on body position. We conclude that only a few autonomic nervous tests are reproducible in the short- and long-term. Because HRV parameters obtained during spontaneous respiration showed high reproducibility for measurements made within the same day as well as in the short- and long-term, they should be used instead of autonomic nervous tests when long-term observations are carried out in a healthy population.

Cardiovascular reflex responses in Bangladeshi and European subjects

1991 ◽  
Vol 80 (1) ◽  
pp. 39-45 ◽  
Author(s):  
M. A. Rahman ◽  
I. Farquhar ◽  
T. Bennett
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Vascular Resistance ◽  
Cardiovascular Responses ◽  
Mean Blood Pressure ◽  
Valsalva Manoeuvre ◽  
Deep Breathing ◽  
Reflex Responses ◽  
Forearm Vascular Resistance

1. Cardiovascular responses to three different interventions, namely the Valsalva manoeuvre, deep breathing and a cold stimulus on the face, were studied in two ethnic groups (European and Bangladeshi) that have been shown to differ in the prevalence of hypertensive-vascular disease. The data obtained consisted of systolic blood pressure, diastolic blood pressure, mean blood pressure, heart rate measured by using a beat-by-beat non-invasive blood pressure monitor (the Finapres), forearm blood flow determined by venous occlusion plethysmography, and calculated forearm vascular resistance. 2. The resting haemodynamic status was similar in European and Bangladeshi subjects. However, Bangladeshi subjects showed a greater increase in heart rate, but only after 20 s into the Valsalva manoeuvre, and greater overshoots in mean blood pressure after the manoeuvre than the European subjects. Furthermore, after cold face stimulation the fall in forearm vascular resistance to baseline levels was delayed in Bangladeshi subjects relative to that in the European subjects. 3. There were no inter-group differences in the reflex bradycardia relative to mean blood pressure or in the cardiac baroreflex sensitivity estimated from systolic blood pressure and pulse interval after the Valsalva manoeuvre. In addition, values for the mean difference between maximum and minimum pulse intervals during deep breathing did not differ in Bangladeshi and European subjects. 4. These findings together suggest that, although cardiac vagal reflex responses appear similar in the two groups, sympatho-adrenal influences on the heart and vasculature may be greater in Bangladeshi subjects than in European subjects.

scholarly journals Chemical Sympathectomy Restores Baroreceptor-Heart Rate Reflex and Heart Rate Variability in Rats With Chronic Nitric Oxide Deficiency

2015 ◽  
pp. 459-466 ◽  
Author(s):  
M. CHASWAL ◽  
S. DAS ◽  
J. PRASAD ◽  
A. KATYAL ◽  
M. FAHIM
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Frequency Domain ◽  
Autonomic Dysfunction ◽  
Sympathetic Innervation ◽  
Chemical Sympathectomy ◽  
Principal Mechanism ◽  
Cardiac Autonomic Dysfunction

Nitric oxide (NO) plays a crucial role not only in regulation of blood pressure but also in maintenance of cardiac autonomic tone and its deficiency induced hypertension is accompanied by cardiac autonomic dysfunction. However, underlying mechanisms are not clearly defined. We hypothesized that sympathetic activation mediates hemodynamic and cardiac autonomic changes consequent to deficient NO synthesis. We used chemical sympathectomy by 6-hydroxydopamine to examine the influence of sympathetic innervation on baroreflex sensitivity (BRS) and heart rate variability (HRV) of chronic NG-nitro-L-arginine methyl ester (L-NAME) treated adult Wistar rats. BRS was determined from heart rate responses to changes in systolic arterial pressure achieved by intravenous administration of phenylephrine and sodium nitroprusside. Time and frequency domain measures of HRV were calculated from 5-min electrocardiogram recordings. Chronic L-NAME administration (50 mg/kg per day for 7 days orally through gavage) in control rats produced significant elevation of blood pressure, tachycardia, attenuation of BRS for bradycardia and tachycardia reflex and fall in time as well as frequency domain parameters of HRV. Sympathectomy completely abolished the pressor as well as tachycardic effect of chronic L-NAME. In addition, BRS and HRV improved after removal of sympathetic influence in chronic L-NAME treated rats. These results support the concept that an exaggerated sympathetic activity is the principal mechanism of chronic L NAME hypertension and associated autonomic dysfunction.

Juvenile fibromyalgia syndrome: Blunted heart rate response and cardiac autonomic dysfunction at diagnosis

2016 ◽  
Vol 46 (3) ◽  
pp. 338-343 ◽  
Author(s):  
Magda M. Maia ◽  
Bruno Gualano ◽  
Ana L. Sá-Pinto ◽  
Adriana M.E. Sallum ◽  
Rosa M.R. Pereira ◽  
...  
Keyword(s):  
Heart Rate ◽  
Autonomic Dysfunction ◽  
Fibromyalgia Syndrome ◽  
Heart Rate Response ◽  
Juvenile Fibromyalgia ◽  
Cardiac Autonomic Dysfunction

Cardiovascular Reflexes in Patients With Vascular Headache

Cephalalgia ◽  
1992 ◽  
Vol 12 (6) ◽  
pp. 360-364 ◽  
Author(s):  
Rosario Martín ◽  
Cristina Ribera ◽  
Jose Manuel Moltó ◽  
Carolina Ruiz ◽  
Luz Galiano ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Healthy Volunteers ◽  
Migraine Without Aura ◽  
Autonomic Function ◽  
Heart Rate Response ◽  
Cardiovascular Reflexes ◽  
Deep Breathing ◽  
Vascular Headache ◽  
Cardiovascular Reflex

We have investigated the autonomic function of 75 patients with migraine by examining cardiovascular reflex function. The results were compared with those of 78 healthy volunteers. Measurements were made between attacks. Patients with migraine showed a smaller heart-rate response to deep breathing but a greater heart-rate response and higher blood pressure to standing when compared to controls. Migraine patients had a higher percentage of established sympathetic lesions (51% vs 17%) and severe (25% vs 5%) or atypical (24% vs 11.5%) global autonomic dysfunction. No significant differences were found among patients with migraine with aura, migraine without aura, and migraine with prolonged aura. Our findings indicate that patients with migraine have sympathetic hypofunction.

scholarly journals Relationship Between Obesity And Parasympathetic Nerve Function

1970 ◽  
Vol 3 ◽  
pp. 50-54
Author(s):  
Shahin Akhtar ◽  
Noorzahan Begum ◽  
Sultana Ferdousi ◽  
Shelina Begum ◽  
Taskina Ali
Keyword(s):  
Heart Rate ◽  
Heart Rate Response ◽  
Autonomic Nerve ◽  
Nerve Function ◽  
Deep Breathing ◽  
Parasympathetic Nerve ◽  
Autonomic Nerve Function ◽  
Obese Subjects ◽  
Healthy Obese ◽  
Apparently Healthy

Back ground: Obesity is a potential risk factor for cardiovascular morbidity and mortality. As certain cardiovascular disorders associated with autonomic nerve which dysfunction often coexist in obese persons, investigations of autonomic nerve function especially parasympathetic nerve function in obese, for detection of early autonomic impairment can be potentially important to prevent complications. Objective: The present study was done to observe the parasympathetic nerve function status in obese persons in order to investigate the relationship of autonomic nerve function with obesity. Study design: This study was conducted in the department of Physiology of Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh during July 2006-June 2007. For these 40 apparently healthy obese subjects of both sexes with BMI ≥ 25 kg/sqm. were included in study group. Age and sex matched 40 apparently healthy non obese subjects with BMI range 18.5-22.9 kg/sqm. were taken as control for comparison. Methods: To assess parasympathetic nerve function status, heart rate response to valsalva(valsalva ratio), heart rate response to deep breathing and heart rate response to standing (30th:15th ratio) were determined by 3 noninvasive cardiovascular reflex tests. Data were collected by recording ECG of all subjects under test condition. The correlations of these parasympathetic nerve function parameters with BMI were also studied. Unpaired Student ‘t' test and Pearson correlation coefficient test were used for statistical analysis. Results: Valsalva ratio (1.47±0.24 vs 1.67±0.31), HR response to deep breathing (19.62±5.55 vs 27.59±6.51) and HR response to standing (1.07±0.07 vs 1.13±0.018) were significantly decreased in obese subjects than those of non obese control. All these parameters were negatively correlated with BMI. and these relatioship were statistically significant. Conclusion: The results of this study indicate that parasympathetic nerve function may be reduced in apparently healthy obese subjects. Key words: Obesity; valsalva; parasympathetic; deep breathing.   doi: 10.3329/jbsp.v3i0.1797 J Bangladesh Soc Physiol.2008 Dec;(3):50-54.

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