Search results for "QRS"
showing 10 items of 37 documents
Cardiac electrical defects in progeroid mice and Hutchinson-Gilford progeria syndrome patients with nuclear lamina alterations
2016
This work was supported by Spanish Ministry of Economy and Competitiveness (MINECO) Grants SAF2010-16044 and SAF2013-46663-R (to V.A.), SAF2011-30312 and SAF2014-58286-C2-1-R (to L.H.-M.), SAF2011-30088 (to E.D.), and SAF2014-52413-R (to C.L.-O.) and Fondo de Investigación Sanitaria del Instituto de Salud Carlos III Grants RD12/0042/0028 (to V.A.), RD12/0042/0011 (to J.T.), and RD12/0042/0002 (to L.H.-M.), with cofunding from the Fondo Europeo de Desarrollo Regional and the Progeria Research Foundation. J.A.G. is the recipient of a U-Mobility Grant from the Marie Curie cofunding of Regional, National and International Programme (Grant 246550). The Instituto Universitario de Oncología is sup…
Optimization of Lead Placement in the Right Ventricle During Cardiac Resynchronization Therapy. A Simulation Study
2019
[EN] Patients suffering from heart failure and left bundle branch block show electrical ventricular dyssynchrony causing an abnormal blood pumping. Cardiac resynchronization therapy (CRT) is recommended for these patients. Patients with positive therapy response normally present QRS shortening and an increased left ventricle (LV) ejection fraction. However, around one third do not respond favorably. Therefore, optimal location of pacing leads, timing delays between leads and/or choosing related biomarkers is crucial to achieve the best possible degree of ventricular synchrony during CRT application. In this study, computational modeling is used to predict the optimal location and delay of p…
Diagnostic electrophysiological study in a highly trained young woman with presyncopal symptoms during exercise: a case report
2021
Right ventricular outflow tract (RVOT) ventricular tachycardia (VT) is frequent and occurs in patients without structural heart disease, especially in highly trained athletes. Most of the studies on cardiac adaptations to exercise have been investigated in male athletes. Women, however, are increasingly participating in sports and electrical and structural adaptations in male and female athletes differ significantly. These cardiac adaptations dissimilarities between males and females have potential implications in diagnosing certain types of arrhythmias. We present here a case of a 35-year-old highly-trained woman endurance athlete that attended the clinic complaining about chest pain and d…
CCDC 2047542: Experimental Crystal Structure Determination
2021
Related Article: Zijie Qiu, Cheng-Wei Ju, Lucas Frédéric, Yunbin Hu, Dieter Schollmeyer, Grégory Pieters, Klaus Müllen, Akimitsu Narita|2021|J.Am.Chem.Soc.|143|4661|doi:10.1021/jacs.0c13197
Evaluation of the pulse wave arrival time as a marker for blood pressure changes in critically ill infants and children
1995
Objective. Pulse arrival time (PAT), which is the interval between the R wave of the electrocardiogram (ECG) and the arrival of the pulse wave peripherally, has been reported to be suitable for use as an indirect measure of blood pressure change. The purpose of this study was to evaluate, in critically ill infants and children, the degree to which 1/PAT covaries with systolic, diastolic, and mean blood pressure, as well as heart rate.Methods. A laboratory device was used to calculate PAT in real time from the ECG and the plethysmographic curve of pulse oximetry used for routine monitoring. Calculated PAT and corresponding blood pressures and heart rate were stored on hard disk. A total of 1…
P and R Wave Detection in Complete Congenital Atrioventricular Block
2009
Complete atrioventricular block (type III AVB) is characterized by an absence of P wave transmission to ventricles. This implies that QRS complexes are generated in an autonomous way and are not coordinated with P waves. This work introduces a new algorithm for the detection of P waves for this type of pathology using non-invasive electrocardiographic surface leads. The proposed algorithm is divided into three stages. In the first stage, the R waves located by a QRS detector are used to generate the RR series and time references for the other stages of the algorithm. In the second stage, the ventricular activity (QT segment) is removed by using an adaptive filter that obtains an averaged pa…
Orderly display of limb lead ECGs raises Chinese intern’s diagnostic accuracy when determining frontal plane QRS axis
2019
Background: There is limited information on whether the orderly display of limb lead ECGs (electrocardiograms) can facilitate students to determine frontal plane QRS complex wave electrical axis. Objectives: The study investigated whether the orderly display of limb lead ECGs can raise Chinese undergraduate intern’s diagnostic accuracy when determining frontal plane axis. Design: A total of 147 fifth-year undergraduate interns aged between 21 and 25 years were randomly arranged into 2 groups: one group was given classically displayed ECGs of limb leads while the other group was given orderly displayed ECGs of limb leads. They were then taught to determine frontal plane axis with one of the …
Suppression of the cardiac electric field artifact from the heart action evoked potential
2006
The study of heart action-related brain potentials is strongly disrupted by the presence of an inherent cardiac electric artifact. The hypothesis is presented that most of the electric current coupled to the cardiac field surrounds the skull and flows through the scalp tissue without crossing the cranial cavity. This pseudo two-dimensional conduction model contrasts with the volumetric conduction of the brain electrical activity, and this property is exploited to cancel the cardiac electric artifact. QRS loop vector-cardiographic projections on saggital planes were recorded in 11 healthy subjects in the head and neck areas. Comparative analysis of the projection eccentricities, estimated by…
The effect of radiofrequency catheter ablation of frequent premature ventricular complexes and arrhythmia burden on left ventricular function
2016
Background: Frequent premature ventricular complexes (PVC) are related to reversible tachycardia-induced cardiomyopathy. However, the role of arrhythmia burden on the outcome of the catheter ablation has not been fully recognised. Aim: The aim of this study was to assess the effect of catheter ablation and PVC burden in patients with and without structural heart disease (SHD) on left ventricular ejection fraction (LVEF). Methods: Transthoracic echocardiography was done before and six months after radiofrequency catheter ablation in 109 consecutive patients (61 men, age 55 ± 17 years) with frequent PVCs. Sixty-five (59.6%) patients had underlying SHD. Results: The catheter ablation procedure…
ADMA, subclinical changes and atrial fibrillation in the general population.
2015
Abstract Background Pathways of oxidative stress, nitric oxide bioavailability and l-arginine derivatives are hypothesized to be related to atrial fibrillation (AF). Circulating methylated l-arginine metabolites can be assessed in the general population and may show an association with AF. Methods We determined l-arginine and its metabolites asymmetric dimethylarginine (ADMA), l-N ω -monomethylarginine (NMMA) and symmetric dimethylarginine (SDMA) in the population-based Gutenberg Health Study (n=5000), mean age 55±11years, 51% men, in association with clinical variables of AF such as electrocardiographic and echocardiographic measures and manifest AF. Results Individuals with AF (N=161), 71…