What Happens before Syncope? Study of the Time Frame Preceding Vasovagal Syncope

Objective. The events characterizing the very last part of the vasovagal crisis has not been determined. The aim of the study was to analyze the variations in respiratory pattern preceding the vaso-vagal syncope full-blown and the relationship between cardiovascular functions in order to assess the temporal sequence. Methods. Eleven consecutive patients were studied. Heart rate, arterial pressure, respiratory frequency, tidal volume, carbon dioxide, and oxygen saturation in time domain from supine and standing recordings were analyzed. Results. The respiratory activity is different in the time frame preceding syncope, both in VT and breathing rate, and that the increase of the lung ventilation does not influence the baroreflex control during the presyncopal period but may be cause of the baroreflex failure during the full-blown syncope

Optical scattering (TAOS) by tire debris particles: preliminary results

Tire debris particles from low severity laboratory wear tests have been investigated by the TAOS optical scattering facility at Yale University. The incident wavelength is 532 nm. After the TAOS event some particle samples have been imaged by a scanning electron microscope and microanalyzed. The TAOS intensity patterns recorded within a solid angle in the backward sector have been processed by cluster analysis and compared with the patterns computed by a T-matrix code. Preliminary agreement has been found between TAOS data and the particle models (size, shape, refractive index). The purpose of the investigation is to obtain signatures of the material, based on its TAOS pattern. © 2001 Optical Society of America

Management of transient loss of consciousness of suspected syncopal cause, after the initial evaluation in the Emergency Department

The recommendations enclosed in the present document have been developed by a group of experts appointed by the Gruppo Multidisciplinare per lo Studio della Sincope (Multidisciplinary Group for the Study of Syncope; GIMSI) and Academy of Emergency Medicine and Care (AcEMC). The aim is to define the diagnostic pathway and the management of patients referred to the Emergency Department (ED) for transient loss of consciousness of suspected syncopal cause, which is still unexplained after the initial evaluation. The risk stratification enables the physician to admit, discharge or monitor shortly the patient in the intensive short-stay Syncope Observation Unit (SOU). There are three risk levels of life-threatening events or serious complications (low, moderate, high). Low risk patients can be discharged, while high risk ones should be monitored and treated properly in case of worsening. Moderate risk patients should undergo clinical and instrumental monitoring in SOU, inside the ED. In all these three cases, patients can be subsequently referred to the Syncope Unit for further diagnostic investigations

Comparison of two methodologies for occupational accidents pre-cursors data collection

Unsafe acts (UA) and unsafe conditions (UC) are commonly considered as accidents pre-cursors. Several methods can be applied to collect accident pre-cursors in different working environment. Re-porting results will be generally influenced by the methodology applied and by the analyst culture. In order to investigate the influence of the above aspects on the reporting results, this study compares two procedures for reporting UA and UC. Both are based on root cause analysis, but the method derived from industrial experience is based on a less structured delayed analysis, while the second model, derived from the HFACS (Hu-man Factors Analysis and Classification System) methodology is more structured and requires an early classi-fication of the event observed and a short interview with the workers involved. The experimental data collection has been carried on in an automotive plant during which the second model has been applied by an external team of analysts, while the on-site personnel were collecting data with the internal methodology. The results compared allows to highlight the effectiveness and the sensitivity of the methodologies

Persistence of baroreceptor control of cerebral blood flow velocity at a simulated altitude of 5000 m

Objective - To assess the effects of acute exposure to simulated high altitude on baroreflex control of mean cerebral blood flow velocity (MCFV). Patients and methods - We compared beat-to-beat changes in RR interval, arterial blood pressure, mean MCFV (by transcranial Doppler velocimetry in the middle cerebral artery), end-tidal CO2, oxygen saturation and respiration in 19 healthy subjects at baseline (Albuquerque, 1779 m), after acute exposure to simulated high altitude in a hypobaric chamber (barometric pressure as at 5000 m) and during oxygen administration (to achieve 100% oxygen saturation) at the same barometric pressure (HOX). Baroreflex control on each signal was assessed by univariate and bivariate power spectral analysis performed on time series obtained during controlled (15 breaths/min) breathing, before and during baroreflex modulation induced by 0.1-Hz sinusoidal neck suction. Results - At baseline, neck suction was able to induce a clear increase in low-frequency power in MCFV (P0.001) as well as in RR and blood pressure. At high altitude, MCFV, as well as RR and blood pressure, was still able to respond to neck suction (all P0.001), compared to controlled breathing alone, despite marked decreases in end-tidal CO2 and oxygen saturation at high altitude. A similar response was obtained at HOX. Phase delay analysis excluded a passive transmission of low-frequency oscillations from arterial pressure to cerebral circulation. Conclusions - During acute exposure to high altitude, cerebral blood flow is still modulated by the autonomic nervous system through the baroreflex, whose sensitivity is not affected by changes in CO2 and oxygen saturation levels

The Impact of COVID-19 Outbreak on Syncope Units Activities in Italy: A Report from the Italian Multidisciplinary Working Group on Syncope (GIMSI)

The aim of our study was to evaluate the impact of the COVID-19 outbreak on Syncope Units (SUs) Activities in Italy. Methods: Data about types of SU activities and admissions were obtained from 10 SUs throughout Italy, certified by the Italian Multidisciplinary Working Group on Syncope (GIMSI), from 10 March 2020 to 31 December 2020 and compared with the same time frame in 2019. Results: A remarkable reduction in overall non-invasive diagnostic tests (−67%; p < 0.001) and cardiac invasive procedure. Elective cardiac pacing procedures disclosed a significant decrease (−62.7%; p < 0.001); conversely, the decrease of urgent procedures was not significant (−50%; p = 0.08). There was a significantly increased rate of patients who underwent both telemedicine follow-up visits (+225%, p < 0.001) and cardiac implantable electronic devices (CIEDs) remote monitoring follow-up visits (+100%; p < 0.001). Conclusion: The COVID-19 outbreak was associated with a remarkable decrease in all clinical activities of Syncope Units in Italy, including both non-invasive tests and cardiac invasive procedures; conversely, a significant increase in telehealth activities was shown