Search results for "Synchro"
showing 10 items of 886 documents
Role of CRT upgrading in pacing induced heart failure: A case report
2014
Abstract We submit a case report of a 78-year-old male came to our department for systolic heart, failure (EF of 25%). He has clinical history of recurring atrial tachycardia and atrial flutter previously treated in our department unsuccessfully with antiarrhythmic drug therapy. The echocardiographic evidence of left atrial enlargement (left atrium area 40 cm 2 ) and the clinical history of permanent atrial tachycardia has discouraged any attempt of substrate ablation. As it is impossible get rhythm and rate control with drug therapy, the patient was subjected to an "ablate and pace" procedure with implantation of a VVIR mode pacemaker. Also, for the absence of indications (QRS width During…
Survival with Cardiac-Resynchronization Therapy in Mild Heart Failure
2014
BACKGROUND The Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT) showed that early intervention with cardiac-resynchronization therapy with a defibrillator (CRT-D) in patients with an electrocardiographic pattern showing left bundle-branch block was associated with a significant reduction in heart-failure events over a median follow-up of 2.4 years, as compared with defibrillator therapy alone. METHODS We evaluated the effect of CRT-D on long-term survival in the MADIT-CRT population. Post-trial follow-up over a median period of 5.6 years was assessed among all 1691 surviving patients (phase 1) and subsequently among 854 patients who w…
Usefulness and limitations of contractile reserve evaluation in patients with low-flow, low-gradient aortic stenosis eligible for cardiac resynchroni…
2014
Aims In low-flow, low-gradient aortic stenosis (LF/LG AS), the assessment of contractile reserve (CR) by dobutamine stress echocardiography (DSE) is recommended for risk stratification and treatment strategy. However, DSE may show limitations in cases of left ventricular dyssynchrony (LVD). The impact of LVD in LF/LG AS, and the feasibility of CRT in this setting have never been evaluated. We aimed to assess: (i) the proportion of LF/LG AS patients with LVD; (ii) the influence of LVD on CR at DSE; and (iii) the effects of CRT in these patients. Methods and results Thirty consecutive patients with LF/LG AS underwent DSE with study of CR. The operative risk for aortic valve replacement (AVR) …
Cardiovascular outcomes after cardiac resynchronization therapy in cardiac amyloidosis
2021
Abstract Aims Cardiac resynchronization therapy (CRT) is highly effective in dilated cardiomyopathy (DCM) patients with impaired left ventricular ejection fraction (LVEF) and left bundle block branch. In cardiac amyloidosis (CA) patients, left ventricular dysfunction and conduction defects are common, but the potential of CRT to improve cardiac remodelling and survival in this particular setting remains undefined. We investigated cardiovascular outcomes in CA patients after CRT implantation in terms of CRT echocardiographic response and major cardiovascular events (MACEs). Methods and results Our retrospective study included 47 CA patients implanted with CRT devices from January 2012 to Feb…
Quantitative assessment of regularity and synchronization of intracardiac recordings during human atrial fibrillation
2003
This study proposes the morphology-based evaluation of the regularity (R) and the synchronization (S) of intra-atrial electrograms acquired during atrial fibrillation (AF). R is defined as the degree of repetitiveness over time of the shapes of the activation waves detected in single atrial recordings. S accounts for the simultaneous presence of morphologically similar activation waves in two atrial electrograms, and for the dispersion of the propagation delays between the two sites. Both R and S resulted unitary for normal sinus rhythm and decreased significantly moving from atrial flutter (R=0.93, S=0.88) to AF of increasing complexity class (type I AF: R=0.75, S=0.66; type II AF: R=0.32,…
Non-responders to cardiac resynchronization therapy: Insights from multimodality imaging and electrocardiography. A brief review
2016
Background Cardiac resynchronization therapy (CRT) is a successful strategy for heart failure (HF) patients. The pre-requisite for the response is the evidence of electrical dyssynchrony on the surface electrocardiogram usually as left bundle branch block (LBBB). Non-response to CRT is a significant problem in clinical practice. Patient selection, inadequate delivery and sub-optimal left ventricle lead position may be important causes. Objectives In an effort to improve CRT response multimodality imaging (especially echocardiography, computed tomography and cardiac magnetic resonance) could play a decisive role and extensive literature has been published on the matter. However, we are so fa…
The QRS narrowing index for easy and early identification of responder to cardiac resynchronization therapy.
2013
The rationale for cardiac resynchronization therapy (CRT) in patients with heart failure (HF) is based on the possibility of inducing substantial left ventricular reverse remodeling. It is well known that some of these patients don't benefit from this therapy (the so-called non-responders) [1,2]. No better predictors of a positive answer to CRT than pre-CRT QRS duration (QRSd) were found [3,4]. The aim of our study was to identify a parameter for an easy and early identification of responders to CRT. In this regard, according to Rickard et al., we identified and observed QRS index (QI), as an expression of electrical remodeling after CRT, and its relation with anatomic reverse remodeling, e…
Anxiety reduction with music and tempo synchronization on magnetic resonance imaging patients
2017
Anxiety and claustrophobic reactions in MRI examinations cause unintentional movements, and such motion artifacts lead to interpretation problems. Furthermore, requested anesthesia makes the process costly. A total of 60 outpatients were examined in the Diagnostic Centre of Pécs, Hungary, to test whether synchronizing recorded music to the gradient pulsation of the MRI device can improve the sedative effect of the music. The patients were assigned to three groups: a nonmusic (control), an original tempo (random) and a synchronized music (synchronous) group. Results showed a significantly decreased state anxiety level after the MRI examination in the random and synchronous groups as compared…
Min-Type Control Strategy of a DC-DC Synchronous Boost Converter
2019
International audience; This paper presents the analysis and design of a min-type strategy to control a synchronous boost converter in continuous conduction mode. The strategy uses a nonlinear switching surface to establish the change of topology in the converter and is analyzed by means of a sliding-mode control approach. Subsequently, the min-type strategy is modified by a hybrid control formulation, which introduces a hysteresis width and a dwell-time to obtain a finite switching frequency in the start-up and steady-state respectively. The hybrid control formulation is implemented digitally by means of a microprocessor which processes the samples of inductor current and capacitor voltage…
Null subjects in generative grammar: A synchronic and diachronic perspective
2018
This book considers the null-subject phenomenon, whereby some languages lack an overtly realized referential subject in specific contexts. In generative syntax-the approach adopted in this volume-the phenomenon has traditionally been explained in terms of a ‘pro-drop’ parameter with associated cluster properties; more recently, however, it has become clear that pro-drop phenomena do not always correlate with all the initially predicted cluster properties. This volume returns to the centre of the debate surrounding the empirical phenomena associated with null subjects. Experts in the field explore the cluster properties associated with pro-drop; the types of null category involved in null-su…