43 research outputs found
QRS pattern and improvement in right and left ventricular function after cardiac resynchronization therapy: a radionuclide study
Predicting response to cardiac resynchronization therapy (CRT) remains a challenge. We evaluated the role of baseline QRS pattern to predict response in terms of improvement in biventricular ejection fraction (EF)
Telecardiology and Remote Monitoring of Implanted Electrical Devices: The Potential for Fresh Clinical Care Perspectives
Telecardiology may help confront the growing burden of monitoring the reliability of implantable defibrillators/pacemakers. Herein, we suggest that the evolving capabilities of implanted devices to monitor patients’ status (heart rhythm, fluid overload, right ventricular pressure, oximetry, etc.) may imply a shift from strictly device-centered follow-up to perspectives centered on the patient (and patient-device interactions). Such approaches could provide improvements in health care delivery and clinical outcomes, especially in the field of heart failure. Major professional, policy, and ethical issues will have to be overcome to enable real-world implementation. This challenge may be relevant for the evolution of our health care systems
The ventricular ectopic QRS interval (VEQSI): Diagnosis of arrhythmogenic right ventricular cardiomyopathy in patients with incomplete disease expression
Analisi dell’andamento plano-altimetrico dei tracciati in relazione alle caratteristiche di deflusso idrico
Obiettivo della memoria è quello di introdurre un nuovo criterio di valutazione dell’andamento plano-altimetrico dei tracciati stradali basato sullo studio delle modalità di deflusso dell’acqua meteorica sui piani viabili.
Differenti situazioni planimetriche (curve destrorse o sinistrorse, flessi) e altimetriche (salita, discesa, raccordi verticali, pendenze longitudinali) portano alla presenza sulla pavimentazione, in condizioni di regime, di quantità maggiori o minori d’acqua, diversamente distribuite sulla sezione trasversale. Ne consegue che, lungo il tracciato, si presentano situazioni di pericolosità differenti nei riguardi dell’aderenza disponibile al contatto tra pneumatico e pavimentazione.
L’obiettivo è stato raggiunto studiando la distribuzione areale dei veli idrici su una pavimentazione qualsiasi in funzione delle caratteristiche geometriche del tracciato e dell’intensità di pioggia.
La superficie stradale viene rappresentata numericamente mediante le coordinate x,y,z del dominio da analizzare ; ciò consente di calcolare le linee di corrente come linee di massima pendenza ed individuare i tubi di flusso a cui applicare gli algoritmi di calcolo che consentono di determinare lo spessore del velo idrico nei diversi punti della pavimentazione per un dato valore dell’intensità di pioggia.
Si sono sviluppati una serie di programmi che come ultimo risultato producono la mappatura della superficie stradale (grafico ad aree) che consente di calcolare una serie di indici caratterizzanti l’estensione delle aree più critiche e la quantità di acqua presente sulla pavimentazione.
Il modello (DEFSTRA) è stato applicato a diverse situazioni plano-altimetriche ed ha consentito di individuare le situazioni potenzialmente più rischiose.
Tale verifica può consentire, in fase di progetto o di verifica di sicurezza dei tracciati, di scegliere in modo mirato le caratteristiche dei manti o gli interventi di riqualifica da adottare
Validation of DEFSTRA Water Film Prediction Model
Water film thickness is one of the main variables influencing the friction values available in the tyre-pavement contact area. Water film depth is influenced by rainfall intensity, grades and cross slopes, length of draining path and pavement texture. During the EU funded VERT and VERTEC research projects an empirical model allowing to evaluate water film depth on constant slope surfaces, having different textures, was developed. The model was afterwards theoretically extended to consider variable slope surfaces and was included in the VERT MBS vehicle model for driving simulations on varying road surfaces in dangerous conditions. The experimental validation of the variable slope water flow model has been implemented by means of a full scale physical road model constructed in the Road Laboratory at the University of Florence. The 3,5 m wide per 24 m long model has a longitudinal grade of 2% and a cross slope varying between +1,5% and – 1,5%. The model is equipped with an artificial rainwater simulation system allowing to simulate rain intensities between 20 and 100 mm/h. The paper will describe the setting up of the road physical model, its calibration and the experimental program performed to validate the water flow model. The results of the experimental study are presented and discussed
Atrial fibrillation: Adverse effects of "pill-in-the-pocket" treatment and propafenone-carvedilol interaction.
Propafenone and carvedilol share a common hepatic metabolism involving the oxidative pathway (CYP2D6). Therefore, oral loading with propafenone (as "pill-in-the-pocket" treatment of recent-onset atrial fibrillation) in a patient on concurrent carvedilol treatment may lead to a pharmacokinetic interaction, with high plasma levels of propafenone and potential drug-related adverse effects. In clinical practice, in order to improve the safety of "pill-in-the-pocket" treatment, use of propafenone loading should, in our view, be discouraged in patients on concurrent treatment with carvedilol
Relationship between Road Surface Characteristics and Noise Emission
The paper summarizes the activities performed by the Roma La Sapienza Partner of the TINO Consortium to fulfill the task of characterizing the pavement texture and relating it to the far and near field noise measurement performed on the same pavements. The testing procedures and results are reported and the final statistical correlation found between texture and noise is described. A new texture index able to characterize the noise performance of the pavement surface and related to the pavement design and construction procedures is proposed
Electrical cardioversion for persistent atrial fibrillation or atrial flutter in clinical practice: predictors of long-term outcome.
Despite the results of Atrial Fibrillation Follow-up Investigation of Rhythm Management and Rate Control versus Electrical Cardioversion for Persistent Atrial Fibrillation trials, which favour a general shift in atrial fibrillation (AF) therapeutic approach towards control of ventricular rate, a strategy based on restoration of sinus rhythm could still play a role in selected patients at lower risk of AF recurrence. We explored possible predictors of relapses after external electrical cardioversion among patients with persistent AF or atrial flutter (AFL). We analysed the clinical characteristics and conventional echocardiographic parameters of patients with persistent AF/AFL enrolled in an institutional electrical cardioversion programme. Among 242 patients (AF/AFL, 195/47; mean age 62+/-13 years), sinus rhythm was restored in 215 (89%) and maintained in 73 (34%) at a follow-up of 930 days (median). No baseline clinical/echocardiographic variables predicted acute efficacy of cardioversion at logistic regression analysis. However, two variables predicted long-term AF/AFL recurrence among patients with successful cardioversion at multivariate Cox's proportional hazards analysis: (i) duration of arrhythmia>or=1 year (HR, 2.07; 95% CI, 1.29-3.33) and (ii) presence of previous cardioversion (HR, 1.67; 95% CI, 1.17-2.38). These variables also presented high-positive predictive values (72% and 80% respectively). Whereas the high acute efficacy of electrical cardioversion (approximately 90%) does not appear to be predictable, two simple clinical variables could help identify patients at higher risk of long-term AF/AFL recurrence after successful electrical cardioversion. We think there could be a case for initially attempting external electrical cardioversion to patients who have had AF/AFL for <1 year. In such patients, the chance of long-term success appears to be relatively high