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PubMed2006

Systematic review: sphincter of Oddi dysfunction--non-invasive diagnostic methods and long-term outcome after endoscopic sphincterotomy.

BACKGROUND: Sphincter of Oddi dysfunction is a benign, functional gastrointestinal disorder for which invasive endoscopic therapy with potential complications is often recommended. AIMS: To review the available evidence regarding the diagnostic accuracy of non-invasive methods that have been used to establish the diagnosis and to estimate the long-term outcome after endoscopic sphincterotomy. METHODS: A systematic review of English language articles and abstracts containing relevant terms was performed. RESULTS: Non-invasive diagnostic methods are limited by their low sensitivity and specificity, especially in patients with Type III sphincter of Oddi dysfunction. Secretin-stimulated magnetic resonance cholangiopancreatography appears to be useful in excluding other potential causes of symptoms, and morphine-provocated hepatobiliary scintigraphy also warrants further study. Approximately 85%, 69% and 37%, of patients with biliary Types I, II and III sphincter of Oddi dysfunction, respectively, experience sustained benefit after endoscopic sphincterotomy. In pancreatic sphincter of Oddi dysfunction, approximately 75% of patients report symptomatic improvement after pancreatic sphincterotomy, but the studies have been non-controlled and heterogeneous. CONCLUSIONS: Patients with suspected sphincter of Oddi dysfunction, particularly those with biliary Type III, should be carefully evaluated before considering sphincter of Oddi manometry and endoscopic sphincterotomy. Further controlled trials are needed to justify the invasive management of patients with biliary Type III and pancreatic sphincter of Oddi dysfunction.

Common Bile Duct Diseases↗

PubMed1987

[Autonomic symptoms in diabetic polyneuropathies].

200 years have gone by since the autonomic disturbance in diabetes mellitus has been described for the first time ever. There is a great deal of information on the close relationship between somatic and visceral symptoms in diabetic polyneuropathy (PNP), so that there should be talked about only of one form of manifestations within the meaning of a distal symmetric somatovisceral PNP. The longer fibres such as the vagal fibres of the viscus, sympathetic fibres of the eye are affected at first and more intensively in the autonomic region same as in the sensory and motor region. Due to the fact that for reasons of fragmentary knowledge pathogenetically substantiated classification of the autonomic disturbances in diabetic PNP is not at hand, such a classification is being made from organotopic and phenomenologic aspects. Frequently, afferent denervation of an organ results in enhancing the effects of an autonomic innervation dysfunction, as for instance in unnoticed hypoglycaemia, in order to modify the symptoms, as for instance in rectal incontinence with unnoticed defecation, or rather to let new symptoms appear, for instance loss of testicular pain. In recent years, appropriate methods of examinations were tested for the clinical routine, permitting to give evidence of autonomic dysfunctions before clinical manifestation. It is still unclear to what extent such subclinical abnormalities are reversible with a more favourable regulation of the metabolic process, for instance with the aid of continuous subcutaneous insulin injections. An impressive symptom of innervation dysfunctions of the cardiovascular system is orthostatic hypertension that may, in exceptional cases, even lead to confinement to bed. The most important pathogenic factor seems to be vascular denervation. A pronounced tachycardia at rest, frequently found in diabetics, is the result of the failure of the vagal autonomic system, and, after additional destruction of the sympathetic fibres, it adjusts itself to a lower level that cannot be changed by reflex mechanisms. Cardialgia absent in the case of myocardial ischemia is a factor of an increased mortality of long-term diabetics. The correlation between vascular denervation and arteriosclerosis or mediasclerosis, respectively, is being under discussion. Denervation on the gastrointestinal tract has an effect on the motility and excretory functions. The innvervation dysfunctions lead to sialadenosis by changing the composition of saliva. In most cases esophageal dysfunction is not perceived by the patient.(ABSTRACT TRUNCATED AT 400 WORDS)

Autonomic Nervous System Diseases↗

PubMed2001

Early volume expansion for prevention of morbidity and mortality in very preterm infants.

BACKGROUND: Reduced perfusion of organs such as the brain, heart, kidneys and the gastrointestinal tract may lead to acute dysfunction and be associated with permanent injury. Various strategies have been used to provide cardiovascular support to preterm infants including inotropes, corticosteroids and volume expansion. OBJECTIVES: In very preterm infants, does early volume expansion reduce morbidity and mortality. If volume expansion is effective, what type of volume expansion is most effective. SEARCH STRATEGY: The standard search strategy of the Neonatal Review Group was used. Searches were conducted of the Oxford Database of Perinatal Trials, Cochrane Controlled Trials Register, MEDLINE, previous reviews including cross references, abstracts and conference proceedings. SELECTION CRITERIA: Randomised trials of early volume expansion with normal saline, fresh frozen plasma, albumin, plasma substitutes or blood compared to no treatment or another form of volume expansion in preterm infants < 32 weeks gestation or < 1500g were included. Volume expansion was defined as at least 10 mls/kg given in the first 72 hours of life. DATA COLLECTION AND ANALYSIS: Standard methods of the Neonatal Review Group with use of relative risk (RR), risk difference (RD) and weighted mean difference (WMD). The fixed effects model using RevMan 4.1 was used for meta-analysis. Data from individual studies were only eligible for inclusion if a least 80% of infants were reported for that outcome. MAIN RESULTS: Seven studies were included. Five studies, four with data for mortality, compared volume to no treatment. Most studies enrolled very preterm infants on the basis of gestation or birthweight. Two studies comparing different types of volume expansion enrolled very preterm infants with hypotension. No study enrolled infants on the basis of low blood flow. One study examined the effect of volume expansion on blood flow but in normotensive very preterm infants. Comparing volume and no treatment, 4 studies with a total of 940 very preterm infants reported no significant difference in mortality (RR 1.11, 95% CI 0.88, 1.40). The large NNNI 1996 study reported no significant difference in severe disability (RR 0.80, 95% CI 0.52, 1.23), cerebral palsy (RR 0.76, 95% CI 0.48, 1.20) and combined death or severe disability (RR 1.00, 95% CI 0.80, 1.24). Although one small study (Beverley 1985) reported reduced P/IVH with volume expansion, this was not supported by any other study. No significant difference was reported in grade 3-4 P/IVH and combined death or grade 3-4 P/IVH. One study (NNNI 1996) reported no significant difference in the incidence of hypotension. The finding of decreased necrotising enterocolitis and increased sepsis in infants who received fresh frozen plasma compared to a gelatin-based plasma substitute or no treatment in one study should be treated with caution. No significant differences in mortality or disability were found in this study. In one small study, there were no significant differences in outcomes between hypotensive infants who received colloid (albumin) or crystalloid (saline). REVIEWER'S CONCLUSIONS: There is no evidence from randomised trials to support the routine use of early volume expansion in very preterm infants without cardiovascular compromise. There is insufficient evidence to determine whether infants with cardiovascular compromise would benefit from volume expansion. There is insufficient evidence to determine what type of volume expansion should be used in preterm infants (if at all) or for the use of early red cell transfusions. The trial comparing colloid (albumin) and crystalloid (saline) in hypotensive preterm infants found no benefit in using a more expensive blood product compared to saline, but is insufficiently powered to detect an important clinical difference.

Blood Volume↗

PubMed2002

Autism and gastrointestinal symptoms.

Autism is a collection of behavioral symptoms characterized by dysfunction in social interaction and communication in affected children. It is typically associated with restrictive, repetitive, and stereotypic behavior and manifests within the first 3 years of life. The cause of this disorder is not known. Over the past decade, a significant upswing in research has occurred to examine the biologic basis of autism. Recent clinical studies have revealed a high prevalence of gastrointestinal symptoms, inflammation, and dysfunction in children with autism. Mild to moderate degrees of inflammation were found in both the upper and lower intestinal tract. In addition, decreased sulfation capacity of the liver, pathologic intestinal permeability, increased secretory response to intravenous secretin injection, and decreased digestive enzyme activities were reported in many children with autism. Treatment of digestive problems appears to have positive effects on autistic behavior. These new observations represent only a piece of the unsolved autism "puzzle" and should stimulate more research into the brain-gut connection.

Acetaminophen↗

PubMed2004

Central nervous system involvement in functional gastrointestinal disorders.

Although functional gastrointestinal disorders (FGID) are common, their pathophysiology remains incompletely understood. It is generally accepted that dysfunction of the bidirectional pathways between the gastrointestinal tract and the central nervous system (the 'brain-gut axis') at any level can cause FGID symptoms. In this review article, we focus on the role of the central nervous system in the brain-gut axis. First, we describe the functional anatomy of the brain-gut axis. Second, we focus on the results from brain-imaging studies both in healthy volunteers and in FGID patients. These new investigational techniques made identification of brain regions critically involved in processing of visceral afferent information possible. Differences in central nervous system response to visceral stimuli between controls and FGID patients will be highlighted. Third, we will address the issue of high comorbidity with psychiatric disorders. Some hypotheses about common pathophysiological substrates will be discussed.

Brain↗

PubMed2003

Increased prevalence of irritable bowel syndrome in patients with bronchial asthma.

Irritable bowel syndrome (IBS) is one of the most common diseases of the gastrointestinal tract. IBS may represent a primary disorder of gastrointestinal motility accompanied with motor dysfunction in various extraintestinal sites. Recent studies suggest that IBS is associated with bronchial hyper-responsiveness and bronchial asthma might be more prevalent in IBS patients than in control subjects. The aim of our study was to assess the prevalence of IBS in a cohort of asthmatic patients. We evaluated 150 patients with bronchial asthma (71 males and 79 females, aged 45.1+/-14.9 years) and two control groups including 130 patients with other pulmonary disorder and 120 healthy subjects. All subjects enrolled (asthmatic and controls) completed the Greek version of the Bowel Disease Questionnaire (BDQ). BDQ is a, previously validated, self-report instrument to measure gastrointestinal symptoms. Diagnosis of IBS was based on Rome II criteria. The IBS prevalence was significantly higher in asthmatics (62/150, 41.3%) than in subjects with other pulmonary disorders (29/130, 22.3%, P<0.001) and healthy ones (25/120, 20.8%, P<0.001). For all subjects studied, the prevalence of IBS was significantly higher in females (78/214, 36.4%) than in males (38/186, 20.4%, P<0.001). The IBS prevalence in asthmatic males was 29.5% vs. 15.2% in male patients with other pulmonary disorders (P=0.002) and 14.2% in male healthy subjects (P=0.002). The IBS prevalence in asthmatic females was 51.8% vs. 28.1% in females patients with other pulmonary disorders (P<0.001) and 26.5% in females healthy subjects (P<0.001). None of the asthma medications were associated with increased or decreased likelihood of IBS. We conclude that patients with bronchial asthma have an increased prevalence of IBS. Further studies are needed to clarify the potential pathogenetic mechanisms underlying the association between IBS and asthma.

Anti-Asthmatic Agents↗

PubMed2003

Autonomic dysfunction in Parkinson's disease.

Autonomic dysfunction in patients with Parkinson's disease (PD) has been recognized since the original description by James Parkinson in 1817. Autonomic failure can be the clinical presentation of other diseases like pure autonomic failure (PAF) and multiple system atrophy (MSA). Both the central and peripheral autonomic nervous systems can be affected in PD. Rajput and Rozdilsky described cell loss and Lewy bodies within the sympathetic ganglia and antibodies to sympathetic neurons have been detected in PD patients. Lewy bodies can be seen in autonomic regulatory regions, including the hypothalamus, sympathetic (intermediolateral nucleus of the thoracic cord and sympathetic ganglia), and parasympathetic system (dorsal, vagal, and sacral parasympathetic nuclei). Lewy bodies were also found in the adrenal medulla and in the neural plexi innervating the gut, heart and pelvis. Symptoms of dysautonomia are variable, and include cardiovascular symptoms, gastrointestinal, urogenital, sudomotor and thermoregulatory dysfunction, pupillary abnormalities and sleep and respiratory disorders. They may represent a useful tool in the differential diagnosis of "atypical" or "complicated" parkinsonisms.

Autonomic Nervous System Diseases↗

PubMed1999

Principles of applied neurogastroenterology: physiology/motility-sensation.

Many of the symptoms characteristic of the functional gastrointestinal disorders (FGID) are consistent with dysfunction of the motor and/or sensory apparatus of the digestive tract. Those aspects of sensorimotor dysfunction most relevant to the FGID include alterations in: gut contractile activity; myoelectrical activity; tone and compliance; and transit, as well as an enhanced sensitivity to distension, in each region of the gastrointestinal tract. Assessment of these phenomena involves a number of techniques, some well established and others requiring further validation. Using such techniques, researchers have reported a wide range of alterations in sensory and in motor function in the FGID. Importantly, however, relationships between such dysfunction and symptoms have been relatively weak, and so the clinical relevance of the former remains unclear. Moreover, the proportions of patients in the various symptom subgroups who display dysfunction, and the extent and severity of their symptoms, require better characterization. On a positive note, progress is occurring on several fronts, especially in relation to functional dyspepsia and irritable bowel syndrome, and based on the data gathered to date, a number of areas where further advances are required can be highlighted.

Colonic Diseases, Functional↗

PubMed1984

[Several functional psychosomatic diseases of the gastrointestinal tract].

Using a clinico-psychological method, 170 patients with functional psychosomatic pathology of the alimentary apparatus (functional dysphagia, neurogenic vomiting, gastralgias, the syndrome of the irritable large intestine) were examined. The study showed that these diseases manifested themselves after a considerable psychotraumatic situation. In women, the role of the stressor was played by disruptions in familial relations while in men, job-related stresses were usually involved. Particular vulnerability of the gastrointestinal tract expressed in episodic dysfunction from early childhood was a predisposing factor in all observations. The personality characteristics of the patients (as judged from the data obtained by techniques of Taylor, Aizenk, M.H.Q., "incompleted sentences" and the index of the stability-instability of marriage) are characterized by high anxiety, neurotism, depression, and liability to obsessive-phobic reactions. Comparison of the research findings with the relevant results obtained in an organic psychosomatic disease (duodenal ulcer) demonstrated that with further somatization of the affect, the above personality features tend to decrease. According to the data obtained functional psychosomatic disturbances progress to organicones only in 7.4% of cases.

Adult↗

PubMed2006

Characterization of intestinal absorption and enterohepatic circulation of mycophenolic Acid and its 7-O-glucuronide in rats.

To assess the mechanism of gastrointestinal disorders by mycophenolate mofetil (MMF), the intestinal absorption and enterohepatic circulation of mycophenolic acid (MPA), an active metabolite of MMF, and its 7-O-glucuronide (MPAG) were investigated using rat intestinal loops and a linked-rat model. The stability of MPAG in the intestinal fluids, the toxicity of MPA and MPAG to intestinal mucosa, and biliary excretion of MPAG in rats with acute renal failure (ARF) were also characterized. MPA was rapidly and extensively absorbed from the rat intestine whereas MPAG was much less absorbable. When MPA was administered intravenously to bile-donor rats, 1.2% of dose was excreted in bile of receiver rats exclusively as MPAG during 4 h. MPAG was minimally deconjugated in the intestinal fluids. MPAG, but not MPA, significantly enhanced the release of lactate dehydrogenase from intestinal mucosa. When MPA was intravenously administered to ARF rats, the biliary excretion of MPAG significantly increased, compared with that in normal rats. These results demonstrated that MPAG accumulated in the intestinal lumen following biliary excretion and exerted some toxic effect on the intestinal mucosa. It was also suggested that enterohepatic circulation of MPAG under renal dysfunction increased the risk of gastrointestinal disorders due to MPAG.

Acute Kidney Injury↗

PubMed1997

Causes and management of recurrent biliary pain after successful nonoperative gallstone treatment.

OBJECTIVE: To evaluate the frequency and causes of recurrent biliary colic after successful extracorporeal shock wave lithotripsy of gallstones. METHODS: Follow-up of 77 patients for 2 yr (median) after complete gallstone clearance by lithotripsy and adjuvant oral litholysis. All patients with recurrent biliary colic were examined thoroughly (laboratory data, ultrasonography, gastroscopy); the examination included gallbladder motility testing. If the patients suffered from additional gastrointestinal complaints, further symptom-guided investigations (pH-metry, lactose absorption study, enteroclysis, colonic transit time, colonoscopy) were performed. Patients without documented gallstone recurrence underwent ERCP and sphincter of Oddi manometry. Cholecystectomy was advised for patients in whom gallstones recurred, and patients with sphincter of Oddi dysfunction underwent endoscopic sphincterotomy. If other gastrointestinal disorders were diagnosed, appropriate treatment was initiated. RESULTS: Twenty-seven patients (35%) experienced biliary colic during follow-up. Gallstone recurrence was documented in 17 patients, and 16 of the patients who underwent cholecystectomy became symptom-free again (follow-up: 12 months). Gallbladder hypomotility was revealed in seven of the 17 patients with gallstone recurrence compared to none of the 10 patients without gallstone recurrence (p < 0.05). Microlithiasis was not detected in bile samples from the patients whose gallstones did not recur. Sphincter of Oddi dysfunction was found in four patients, and sphincterotomy cured all of them (follow-up: 9 months). Two of the remaining six patients had functional gastrointestinal disorders (reflux, constipation) and became asymptomatic after specific treatment. CONCLUSIONS: Biliary colic often recurs after successful gallstone lithotripsy. Recurrent gallbladder stones are the main cause, but another cause is sphincter of Oddi dysfunction. Neither gallbladder hypomotility nor microlithiasis seems to cause biliary symptoms in patients without recurrence of gallstones.

Adult↗

PubMed1996

SIRS, MODS and tertiary peritonitis.

Some patients with peritonitis develop a septic response without a detectable infective focus. It is suggested that an immunological dysfunction is responsible for this so called tertiary peritonitis. The role of the gastrointestinal tract in the development of multiple organ dysfunction syndrome (MODS) is discussed. In patients with tertiary peritonitis treatment should be directed towards restoration of the immunological balance, which is probably more important than the elimination of microorganisms with antibiotics.

Anti-Bacterial Agents↗

PubMed1998

Impairment of phagocytic and T-cell-mediated antibacterial activity and plasma endotoxins in patients with untreated gastrointestinal cancer.

BACKGROUND: Cancer patients have multiple immune deficits, and mediators, such as prostaglandins, transforming growth factor-beta, and interleukin (IL)-10, may play a role in the pathogenesis of these immune dysfunctions. METHODS: Fifty-six patients with gastrointestinal cancer (11 gastric cancer, 7 papilla of Vater cancer, and 38 colorectal cancer) were enrolled for this study, before starting conventional treatments. Phagocytosis and killing exerted by polymorphonuclear cells and monocytes, peripheral blood mononuclear cell absolute numbers, T-cell-mediated antibacterial activity, serum levels of IL-10 and interferon (IFN)-gamma, and plasma bacterial endotoxin concentration were evaluated. RESULTS: Data show an impaired phagocytic and T-cell-mediated antibacterial activity in all cancer patients, whereas only in subjects with gastric cancer were IFN-gamma serum levels reduced. Circulating endotoxins were detected in 17 patients. CONCLUSIONS: In untreated gastrointestinal cancer patients the capacity of phagocytes and T-cells to clear pathogens is reduced. This dysfunction may increase the risk of becoming infected and may account for the presence of endotoxin in 30% of patients.

Adult↗

PubMed1989

Gastric and oesophageal emptying in patients with type 2 (non-insulin-dependent) diabetes mellitus.

Gastric emptying of a digestible solid and liquid meal and oesophageal emptying of a solid bolus were measured with scintigraphic techniques in 20 randomly selected Type 2 (non-insulin-dependent) diabetic patients receiving oral hypoglycaemic therapy and 20 control subjects. In the diabetic patients, the relationships between oesophageal emptying, gastric emptying, gastrointestinal symptoms, autonomic nerve function and glycaemic control were examined. The percentage of the solid meal remaining in the stomach at 100 min (p less than 0.001), the 50% gastric emptying time for the liquid meal (p less than 0.05) and oesophageal emptying (p less than 0.05) were slower in the diabetic patients compared to the control subjects. Scores for upper gastrointestinal symptoms and autonomic nerve dysfunction did not correlate significantly (p greater than 0.05) with oesophageal, or gastric emptying. The 50% gastric emptying time for the liquid meal was positively related (r = 0.58, p less than 0.01) to the plasma glucose concentration at the time of the performance of the gastric emptying test and the lag period, before any solid food emptied from the stomach, was longer (p less than 0.05) in subjects with plasma glucose concentrations during the gastric emptying measurement greater than the median, compared to those with glucose concentrations below the median. These results indicate that delayed gastric and oesophageal emptying occur frequently in Type 2 diabetes mellitus and that delayed gastric emptying relates, at least in part, to plasma glucose concentrations.

Aged↗

PubMed1991

Cirrhosis and portal hypertension in a patient with adult Niemann-Pick disease.

A woman with known Niemann-Pick disease, type B, presented at age 33 with upper gastrointestinal bleeding, ascites, and peripheral edema. Evaluation showed massive hepatosplenomegaly, infiltration of the liver with Niemann-Pick cells, cirrhosis, and evidence of portal hypertension. Chronic gastrointestinal bleeding, thrombocyctopenia, and platelet dysfunction were treated successfully by splenectomy. Cirrhosis and portal hypertension have not been reported previously in adult Niemann-Pick disease in the absence of some other cause.

Adult↗

PubMed1999

Heparin-coated cardiopulmonary bypass equipment. I. Biocompatibility markers and development of complications in a high-risk population.

OBJECTIVES: 1. To study possible clinical benefits of heparin-coated cardiopulmonary bypass in patients with a broad range of preoperative risk factors. 2. To evaluate the correlation between the terminal complement complex and clinical outcome. 3. To identify clinical predictors of complement activation and correlates of granulocyte activation during cardiac surgery. METHODS: Blood samples from adults undergoing elective cardiac surgery with Duraflo II heparin-coated (n = 81) or uncoated (n = 75) cardiopulmonary bypass sets (Duraflo coating surface; Baxter International, Inc, Deerfield, Ill) were analyzed for activation of complement (C3 activation products, terminal complement complex), granulocytes (myeloperoxidase, lactoferrin), and platelets (beta-thromboglobulin) by enzyme immunoassays. Preoperative risk was assessed by means of the "Higgins' score." Complications (cardiac, renal, pulmonary, gastrointestinal, and central nervous system dysfunction, infections, death) were registered prospectively. Data were analyzed by analysis of variance, logistic regression, and linear regression. RESULTS AND CONCLUSIONS: Sixty-seven percent of the patients had predefined risk factors. Complications developed in 53 patients (34%), equivalently with and without heparin-coated bypass sets (P =. 44-.82), despite a significant reduction in complement and granulocyte activation by heparin coating. No clear-cut relationship between the terminal complement complex and outcome was found, even if it was significant in the models for renal and central nervous system dysfunction and infections (P =.006). The Higgins' score was significantly related to complement activation (P <.05). Approximately 50% of the variation in granulocyte activation was explained by complement (P </=.01) and platelet activation (P <.05), heparin/protamine dose ratio (P =.02), duration of cardiopulmonary bypass (P <.01), and gender (P <.05). Therefore measures reducing complement activation alone will not necessarily reduce granulocyte activation sufficiently for clinical significance.

Aged↗

PubMed2003

Prenatal management of gastroschisis: the place of the amnioexchange procedure.

Gastroschisis is a malformation of the anterior abdominal wall that consists of a right paraumbilical defect with bowel loops bathed in the amniotic fluid. The survival rate is now greater than 90% and the prognosis relies mainly on morbidity attributable to bowel dysfunction. Recent research has examined gastrointestinal waste present in amniotic fluid that induces bowel toxicity and an inflammatory process. The amnioexchange procedure (changing the amniotic fluid regularly) involves a new therapeutic approach: reducing bowel injuries in the fetuses. This article shows that there is an inflammatory reaction in human gastroschisis and in the authors' model, and that the clinical and biological data plead for the practice of amnioexchange in human beings. A randomized, controlled study is now needed.

Amniotic Fluid↗

PubMed1996

Postural tachycardia syndrome: time frequency mapping.

Orthostatic tachycardia is common but its specificity remains uncertain. Our preliminary work suggested that using autonomic function testing in conjunction with time-frequency mapping (TFM), it might be possible to characterize a subset of the postural tachycardia syndrome (POTS), that is due to a restricted autonomic neuropathy. We describe 20 patients (17 women and 3 men, aged 14-43 years) with florid POTS and 20 controls (14 women and 6 men, aged 20-41 years). Autonomic failure was quantified by its distribution (cardiovagal, adrenergic and sudomotor) and severity, a symptom profile was generated, and spectral indices, based on modified Wigner distribution during rest and head-up tilt (80 degrees) were evaluated. During tilt-up POTS patients differed from controls by an excessive heart rate (> 130 bpm) (P < 0.001), and higher diastolic pressure (P < 0.01). During rest, cardiovagal oscillations (at respiratory frequencies [RF]) and slow rhythms at nonrespiratory frequencies (NONRF) (from 0.01 to 0.07 Hz) in R-R intervals (RRI) (P < 0.01) were reduced. Both RF and NONRF rhythms in RRI were further blunted with tilt-up (P < 0.001). Slow adrenergic vasomotor rhythms in blood pressure (BP) (approximately 0.07 Hz) surged with tilt-up and returned to normal levels afterwards. The index of sympatho-vagal balance (NONRF-Systolic BP (SBP)/RF-RRI) was dramatically increased in POTS (P < 0.001). Distal postganglionic sudomotor failure was observed, and impairment of the BP responses to the Valsalva maneuver (phase II) suggested peripheral adrenergic dysfunction. Persistent orthostatic dizziness, tiredness, gastrointestinal symptoms and palpitations were common in POTS patients. It is possible to identify a subset of POTS patients who have a length-dependent autonomic neuropathy, affecting the peripheral adrenergic and cardiovagal fibers, with relative preservation of cardiac adrenergic fibers.

Adolescent↗