Search results for "Syncope"
showing 10 items of 35 documents
Cerebrovascular and cardiovascular variability interactions investigated through conditional joint transfer entropy in subjects prone to postural syn…
2017
Objective: A model-based conditional transfer entropy approach was exploited to quantify the information transfer in cerebrovascular (CBV) and cardiovascular (CV) systems in subjects prone to develop postural syncope. Approach: Spontaneous beat-to-beat variations of mean cerebral blood flow velocity (MCBFV) derived from a transcranial Doppler device, heart period (HP) derived from surface electrocardiogram, mean arterial pressure (MAP) and systolic arterial pressure (SAP) derived from finger plethysmographic arterial pressure device were monitored at rest in supine position (REST) and during 60° head-up tilt (TILT) in 13 individuals (age mean ± standard deviation: 28 ± 9 years, min-max r…
Side-effects of extracorporeal shock wave therapy (ESWT) in the treatment of tennis elbow
2002
Apart from a few observational reports, there are no studies on the side-effects of extracorporeal shock wave therapy (ESWT) in the treatment of insertion tendopathies. Within the framework of a randomised, placebo-controlled, single-blind, multicentre study to test the effectiveness of ESWT in the case of lateral epicondylitis (LE), side-effects were systematically recorded. A total of 272 patients from 15 centres was allocated at random to active ESWT (3 x 2000 pulses, energy flux density ED(+) 0.04 to 0.22 mJ/mm(2) under local anaesthesia) or placebo ESWT. In all, 399 ESWT and 402 placebo treatments were analysed. More side-effects were documented in the ESWT group (OR = 4.3, CI = [2.9; …
Syncope in the German Nationwide inpatient sample – Syncope in atrial fibrillation/flutter is related to pulmonary embolism and is accompanied by hig…
2019
Syncope is a common phenomenon in the general population. Although most of the causes are of benign origin, some comorbidities are accompanied by high mortality. We aimed to compare the in-hospital mortality of patients with syncope related to different comorbities and investigate the impact of syncope in patients with atrial fibrillation/flutter (AF).The nationwide inpatient sample of Germany of the years 2011-2014 was used for this analysis. Patients with syncope (ICD-code R55) were stratified by presence of selected comorbidities. Additionally, AF patients with and without syncope were compared. Incidence of syncope and in-hospital mortality were calculated. Syncope as a predictor of adv…
Causal cross-spectral analysis of heart rate and blood pressure variability for describing the impairment of the cardiovascular control in neurally m…
2006
A causal approach to the calculation of coherence and transfer function between systolic pressure (SP) and RR interval variability was applied in eight patients and eight control subjects during prolonged tilt test for investigating the impairment of cardiovascular control related to neurally mediated syncope. The causal analysis showed a depressed baroreflex regulation in resting patients, with reduced gain and increased latency from SP to RR, and a drop of the baroreflex coupling immediately before syncope. These findings, which were not elicited by traditional cross-spectral analysis, strongly suggest the use of the causal approach for the study of syncope mechanisms. © 2006 IEEE.
Strength and Latency of the HP-SAP Closed Loop Variability Interactions in Subjects Prone to Develop Postural Syncope
2019
The coupling and latency between heart period (HP) and systolic arterial pressure (SAP) variability can be investigated along the two arms of the HP-SAP closed loop, namely along the baroreflex feedback from SAP to HP, and along the feedforward pathway from HP to SAP. This study investigates the HP-SAP closed loop variability interactions through cross-correlation function (CCF). Coupling strength and delay between HP and SAP variability series were monitored in 13 subjects prone to develop orthostatic syncope (SYNC, 28±9 yrs, 5 males) and in 13 subjects with no history of postural syncope (noSYNC, age: 27±8 yrs, 5 males). Analysis was carried out at rest in supine position (REST) and durin…
Assessing Causality in normal and impaired short-term cardiovascular regulation via nonlinear prediction methods
2009
We investigated the ability of mutual nonlinear prediction methods to assess causal interactions in short-term cardiovascular variability during normal and impaired conditions. Directional interactions between heart period (RR interval of the ECG) and systolic arterial pressure (SAP) short-term variability series were quantified as the cross-predictability (CP) of one series given the other, and as the predictability improvement (PI) yielded by the inclusion of samples of one series into the prediction of the other series. Nonlinear prediction was performed through global approximation (GA), approximation with locally constant models (LA0) and approximation with locally linear models (LA1) …
Spectral decomposition of cerebrovascular and cardiovascular interactions in patients prone to postural syncope and healthy controls.
2022
We present a framework for the linear parametric analysis of pairwise interactions in bivariate time series in the time and frequency domains, which allows the evaluation of total, causal and instantaneous interactions and connects time- and frequency-domain measures. The framework is applied to physiological time series to investigate the cerebrovascular regulation from the variability of mean cerebral blood flow velocity (CBFV) and mean arterial pressure (MAP), and the cardiovascular regulation from the variability of heart period (HP) and systolic arterial pressure (SAP). We analyze time series acquired at rest and during the early and late phase of head-up tilt in subjects developing or…
Hipertensión arterial episódica asociada al síndrome de taquicardia postural ortostática
2006
Se presenta el caso clínico de una mujer de 17 años de edad que acude en reiteradas ocasiones a urgencias por palpitaciones, taquicardia, síncope, reacción vegetativa de escasa duración, con recuperación espontánea y completa y detección de cifras elevadas de presión arterial. Estudiada en diversas consultas de especialidades y tras múltiples exploraciones complementarias no se encontró patología que justificase el cuadro. Ante la sospecha de intolerancia ortostática o síndrome de taquicardia postural ortostática con hipertensión se realizó la prueba de estimulación con cama basculante a 60°, confirmándose el diagnóstico y comprobando la desaparición de los síntomas al iniciar tratamiento c…
Misdiagnosis and pitfalls in Panayiotopoulos syndrome
2019
Abstract Panayiotopoulos syndrome (PS) is a frequent (6% among children of 1–15 years) and benign epileptic syndrome, characterized by predominantly autonomic symptoms (emesis, pallor, flushing, cyanosis, mydriasis/miosis, cardiorespiratory and thermoregulatory alterations, incontinence of urine and/or feces, hypersalivation, and modifications of intestinal motility) associated with simple motor focal seizures, which can be followed by secondary generalization. Panayiotopoulos syndrome can be extremely insidious, because it can mimic several condition, such as gastroenteritis, gastroesophageal reflux disease, encephalitis, syncope, migraine, sleep disorders, or even metabolic diseases. This…
Investigating the mechanisms of cardiovascular and cerebrovascular regulation in orthostatic syncope through an information decomposition strategy
2012
Some previous evidence suggests that postural related syncope is associated with defective mechanisms of cerebrovascular (CB) and cardiovascular (CV) control. We characterized the information processing in short-term CB regulation, from the variability of mean cerebral blood flow velocity (CBFV) and mean arterial pressure (AP), and in CV regulation, from the variability of heart period (HP) and systolic AP (SAP), in ten young subjects developing orthostatic syncope in response to prolonged head-up tilt testing. We exploited a novel information-theoretic approach that decomposes the information associated with a variability series into three amounts: the information stored in the series, the…