Antonio Roberto Zamunér

Driving and working with syncope.

Syncope is usually addressed in the Emergency Department (ED) by the doctor in charge of the clinical picture, i.e. the patients risk is stratified, a diagnostic work-up is done and a prognosis is set. Patients are ultimately admitted to hospital or discharged. However, other aspects related to syncope may deeply affect their daily lives. These include how and when to return to work and to driving, the feelings about a recent loss of consciousness, and the potential relapse of syncope. This is particularly significant if the work setting is intrinsically hazardous. These patients need adequate clinical and psychological support. For patients with syncope, two main parameters should be considered regarding returning to work and to driving. The first is to evaluate the risk of syncope recurrence and the second is to consider the expected harm if syncope does indeed occur during these activities. In the present paper we detail the problem of driving (including professional driving) and work after syncope. We propose a new quantitative model that will guide the physician in stratifying the risk for patients who have had a previous syncope event. The new model considers the syncope recurrence risk, the job task duration, and features that facilitate a syncope during work. On the basis of these variables, the global risk index for a worker is calculated. Following appropriate validation, this method might help ED and occupational physicians in their decision-making process with the goal of safely readmitting syncope patients to the workplace.

Cardiovascular parameters and neural sympathetic discharge variability before orthostatic syncope: role of sympathetic baroreflex control to the vessels

We tested the hypothesis that altered sympathetic baroreceptor control to the vessels (svBRS) and disrupted coupling between blood pressure (BP) fluctuations and muscle sympathetic activity (MSNA) discharge pattern in the low frequency band (LF, around 0.1 Hz) precede vasovagal syncope. Seven healthy males underwent ECG, BP, respiratory, and MSNA recordings at baseline (REST) and during a 15 min 80° head-up tilt, followed by a -10 mmHg step wise increase of lower body negative pressure up to presyncope. Spectral and coherence analyses of systolic arterial pressure (SAP) and MSNA variability provided the indexes of vascular sympathetic modulation, LFSAP, and of the linear coupling between MSNA and SAP in the low frequency band (around 0.1 Hz), K(2)MSNA-SAP(LF). svBRS was assessed as the slope of the regression line between MSNA and diastolic arterial pressure (DAP). Data were analyzed at REST, during asymptomatic and presyncope periods of tilt. svBRS declined during presyncope period compared to REST and asymptomatic tilt. The presyncope period was characterized by a decrease of RR interval, LFMSNA, LFSAP, and K(2)MSNA-SAP(LF) values compared to the asymptomatic one, whereas MSNA burst rate was unchanged. The reduction of svBRS producing an altered coupling between MSNA and SAP variability at 0.1 Hz, may provoke circulatory changes leading to presyncope.

Effects of wheelchair sports on respiratory muscle strength and thoracic mobility of individuals with spinal cord injury.

Objective The aim of this study was to evaluate the effects of wheelchair sports on respiratory muscle strength and the thoracic mobility of individuals with spinal cord injury. Design Thirty male subjects with chronic spinal cord injury (American Spinal Injury Association Impairment Scale grade A) took part in the study and were divided into four groups: sedentary subjects with quadriplegia (S-QUAD, n = 7), wheelchair rugby athletes with quadriplegia (A-QUAD, n = 8), sedentary subjects with paraplegia (S-PARA, n = 6), and wheelchair basketball athletes with paraplegia (A-PARA, n = 9). The main outcome measures were maximal inspiratory and expiratory pressure and the respiratory coefficients at the axillary and xiphoid levels. Results A-QUAD group presented values significantly higher for all respiratory variables studied compared with the S-QUAD group. No significant differences in any of the respiratory variables were observed between S-PARA and A-PARA groups. There was a negative correlation between spinal cord injury level and respiratory variables for the S-QUAD and S-PARA groups. There were positive correlations in the A-QUAD group between time of training and maximal inspiratory pressure (adjusted R2 = 0.84; P = 0.001) and respiratory coefficients at the axillary level (adjusted R2 = 0.80; P = 0.002). Conclusions Physical training seems to have a positive influence on respiratory muscle strength and thoracic mobility, especially in subjects with quadriplegia.

Cardiovascular control in women with fibromyalgia syndrome: do causal methods provide nonredundant information compared with more traditional approaches?

The cardiovascular autonomic control and the baroreflex sensitivity (BRS) have been widely studied in fibromyalgia syndrome (FMS) patients through the computation of linear indices of spontaneous heart period (HP) and systolic arterial pressure (SAP) variabilities. However, there are many methodological difficulties regarding the quantification of BRS by the traditional indices especially in relation to the issue of causality. This difficulty has been directly tackled via a model-based approach describing the closed-loop HP-SAP interactions and the exogenous influences of respiration. Therefore, we aimed to assess whether the BRS assessed by the model-based causal closed-loop approach during supine and active standing in patients with FMS could provide complementary information to those obtained by traditional indices based on time and frequency domains. The findings of this study revealed that, at difference with the traditional methods to quantify BRS, the causality analysis applied to the HP, SAP, and respiratory series, through the model-based closed-loop approach, detected lower BRS in supine position, as well as a blunted response to the orthostatic stimulus in patients with FMS compared with healthy control subjects. Also, the strength of the causal relation from SAP to HP (i.e., along the cardiac baroreflex) increased during the active standing only in the control subjects. The model-based closed-loop approach proved to provide important complementary information about the cardiovascular autonomic control in patients with FMS.

Autonomic modulation of heart rate in paraplegic wheelchair basketball players: Linear and nonlinear analysis

Abstract This study aimed to evaluate the autonomic modulation of heart rate in sedentary paraplegics and paraplegic wheelchair basketball players with thoracic spinal cord injury below T6. Seven paraplegic wheelchair basketball players (active paraplegic group), five paraplegics who were not involved in regular exercise (sedentary paraplegic group) and 10 able-bodied participants (control group) took part in the study. The heart rate variability was evaluated by linear (low frequency and high frequency band in normalised units and low frequency/high frequency ratio) and nonlinear methods (Shannon entropy, corrected conditional entropy, and symbolic analysis). The sedentary group presented significantly higher values for low frequency, low frequency/high frequency ratio and symbolic index with no significant variations (0V%), and also lower values for the high frequency and symbolic index with two significant unlike variation (2ULV%) compared to active paraplegic group. Shannon entropy and corrected conditional entropy analyses revealed significantly lower values in the sedentary group than in the control or active paraplegic groups. Paraplegic individuals who regularly undertake physical exercise have higher complexity of R-R interval time series, lower sympathetic modulation, and higher parasympathetic modulation than sedentary paraplegic participants.

Three-dimensional scapular motion during arm elevation is altered in women with fibromyalgia.

BACKGROUND The core feature of fibromyalgia is pain, which may play a role in various mechanisms that might lead to alterations in shoulder kinematics. Alterations in muscle activity and presence of tender points in the shoulder girdle have already been described in this population; however there is lack of evidence on three-dimensional scapular motion in women with fibromyalgia. METHODS Forty women with fibromyalgia and 25 healthy women (control group) matched in terms of age, weight and height, took part in this study. Three-dimensional scapular kinematics of the dominant arm were collected during elevation and lowering of the arm in the sagittal and scapular planes. Pain was evaluated by the Visual Analogue Scale and the Numerical Pain Rating Scale. Group comparisons were performed with one-way ANOVA for pain and two-way ANOVA for the kinematic variables (scapular internal/external rotation, upward/downward rotation and anterior/posterior tilt), with group and humeral elevation angle as categorical factors. Significance level was set at P<0.05. FINDINGS Fibromyalgia women presented higher pain scores (P<0.001) than the control group. Fibromyalgia women also presented greater scapular upward rotation (P<0.001, both planes) and greater scapular posterior tilt (P<0.001, both planes) than the control group. INTERPRETATION Women with fibromyalgia present greater scapular upward rotation and posterior tilt in the resting position and during arm elevation and lowering of the arm in sagittal and scapular planes. These alterations may be a compensatory mechanism to reduce pain during arm movement.

Respiratory Sinus Arrhythmia and its Association with Pain in Women with Fibromyalgia Syndrome.

To assess the cardiac autonomic control at rest and during the deep breathing test (DBT) and its association with pain in women with fibromyalgia syndrome (FMS).

Lung Function, Respiratory Muscle Strength, and Thoracoabdominal Mobility in Women With Fibromyalgia Syndrome

BACKGROUND: Fibromyalgia syndrome (FMS) is associated with a variety of symptoms, such as fatigue and dyspnea, which may be related to changes in the respiratory system. The objective of this work was to evaluate pulmonary function, respiratory muscle strength, and thoracoabdominal mobility in women with FMS and its association with clinical manifestations. METHODS: The study included 23 women with FMS and 23 healthy women (control group). Pulmonary function, respiratory muscle strength, and thoracoabdominal mobility were assessed in all participants. Clinical manifestations such as number of active tender points, pain, fatigue, well-being, and general pressure pain threshold and pressure pain threshold in regions involved in respiratory function were also assessed. For data analysis, the Mann-Whitney test and Spearman correlation coefficient were used. RESULTS: The FMS group showed lower values of maximum voluntary ventilation (P = .030), maximal inspiratory pressure (P = .003), and cirtometry at the axillary and xiphoid levels (P < .001 and P < .001, respectively) as well as higher cirtometry at the abdominal level (P = .005) compared with the control group. However, there was no significant difference between groups for maximum expiratory pressure. In predicted percentage, maximal inspiratory pressure showed significant positive correlation with axillary cirtometry (r = 0.41, P = .049) and negative correlation with the number of active tender points (r = −0.44, P = .031) and fatigue (r = −0.41, P = .049). CONCLUSIONS: Subjects with FMS had lower respiratory muscle endurance, inspiratory muscle strength, and thoracic mobility than healthy subjects. In addition, inspiratory muscle strength was associated with the number of active tender points, fatigue, and axillary mobility.

Linear and Nonlinear Analyses of the Cardiac Autonomic Control in Children With Developmental Coordination Disorder: A Case-Control Study

Children with Developmental Coordination Disorder (DCD) and children at risk for DCD (r-DCD) present motor impairments interfering in their school, leisure and daily activities. In addition, these children may have abnormalities in their cardiac autonomic control, which together with their motor impairments, restrict their health and functionality. Therefore, this study aimed to assess the cardiac autonomic control, by linear and nonlinear analysis, at supine and during an orthostatic stimulus in DCD, r-DCD and typically developed children. Thirteen DCD children (11 boys and 2 girls, aged 8.08 ± 0.79 years), 19 children at risk for DCD (13 boys and 6 girls, aged 8.10 ± 0.96 years) and 18 typically developed children, who constituted the control group (CG) (10 boys and 8 girls, aged 8.50 ± 0.96 years) underwent a heart rate variability (HRV) examination. R-R intervals were recorded in order to assess the cardiac autonomic control using a validated HR monitor. HRV was analyzed by linear and nonlinear methods and compared between r-DCD, DCD, and CG. The DCD group presented blunted cardiac autonomic adjustment to the orthostatic stimulus, which was not observed in r-DCD and CG. Regarding nonlinear analysis of HRV, the DCD group presented lower parasympathetic modulation in the supine position compared to the r-DCD and CG groups. In the within group analysis, only the DCD group did not increase HR from supine to standing posture. Symbolic analysis revealed a significant decrease in 2LV (p < 0.0001) and 2UV (p < 0.0001) indices from supine to orthostatic posture only in the CG. In conclusion, r-DCD and DCD children present cardiac autonomic dysfunction characterized by higher sympathetic, lower parasympathetic and lower complexity of cardiac autonomic control in the supine position, as well as a blunted autonomic adjustment to the orthostatic stimulus. Therefore, cardiovascular health improvement should be part of DCD childrens management, even in cases of less severe motor impairment.

Ratings of perceived exertion at anaerobic threshold in patients with coronary artery disease

O objetivo do estudo foi identificar e comparar a percepcao subjetiva do esforco (PSE) no limiar anaerobio ventilatorio (LAV) em individuos saudaveis e com doenca arterial coronariana (DAC). Foram estudados 30 homens, sendo 10 saudaveis que constituiram o grupo controle (GC) e 20 diagnosticados com DAC, dos quais 10 faziam uso de medicamento betabloqueador (G-DACb) e 10 nao faziam uso (G-DAC). Os voluntarios foram submetidos a um teste de exercicio cardiopulmonar (TECP) com protocolo continuo tipo rampa para determinacao do LAV, atraves da analise visual grafica (perda do paralelismo entre o consumo de oxigenio e a producao de dioxido de carbono). Durante a realizacao do TECP, foi solicitado aos voluntarios que relatassem ao final de cada minuto a percepcao subjetiva do esforco de membros inferiores (PSE-M) e a percepcao subjetiva do esforco respiratorio (PSE-R), atraves da escala CR-10 de Borg. O GC apresentou maiores valores de potencia, consumo de oxigenio, producao de dioxido de carbono, ventilacao e frequencia cardiaca no LAV comparado aos grupos G-DAC e G-DACb (p ;0,05). Valores entre cinco e seis na escala CR-10 de Borg correspondeu ao LAV na amostra estudada. Entretanto, outros parâmetros devem ser utilizados concomitantemente para a prescricao da intensidade de exercicio nos protocolos de treinamento fisico, em niveis proximos ao LAV para pacientes com DAC.