Sökning: "repolarization"

Visar resultat 6 - 10 av 28 avhandlingar innehållade ordet repolarization.

1. 6. Global sequence and dispersion of ventricular repolarization: In vivo validation of non-invasive parameters using monophasic action potential mapping technique

   Författare :Yunlong Xia; Kardiologi; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Kardiovaskulära systemet; Cardiovascular system; dispersion; electroanatomical mapping; T wave; epicardial pacing; Ventricular repolarization; monophasic action potential;

   Sammanfattning : The purposes are to validate the noninvasive parameters, QT interval, QT dispersion, Tpeak-Tend interval, and the activation recovery time (ART) for estimation of global dispersion of ventricular repolarization (DVR), and to investigate the changes of repolarization sequence and DVR by altered ventricular pacing sites. The material consisted of 12 patients (Study I) and two series healthy pigs with 10 in each (Studies II and III; Studies IV and V). LÄS MER

3. 7. Ventricular repolarization in the human heart : effects of pharmacological and non-pharmacological interventions

   Författare :Karolina J. Nowinski; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :QT interval; QT dispersion; PTCA; ischemia; T vector loop; AV junctional RF ablation; arrhythmia; sex hormones; hormone replacement therapy; cardiac memory ECG; signal-averaged ECG;

   Sammanfattning : Ventricular arrhythmias is the main cause of sudden cardiac death. A prolonged repolarization might cause such arrhythmias, and an increased understanding about mechanisms is therefore important for their primary and secondary prevention. LÄS MER

4. 8. SEQUENCE AND DISPERSION OF VENTRICULAR REPOLARIZATION ON THE ENDOCARDIUM AND EPICARDIUM Studies using the monophasic action potential mapping technique in humans and pigs

   Författare :Ole Kongstad Rasmussen; Kardiologi; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Cardiovascular system; Kardiovaskulära systemet; ventricle; epicardium; endocardium; Monophasic action potential mapping Repolarization sequence; Global dispersion;

   Sammanfattning : Materials and Methods: Monophasic action potential (MAP) were recorded, using the CARTO mapping system and NaviStar catheters, during sinus rhythm from the endocardium at 43 ± 15 LV or RV sites in 8 patients, at 61 ± 18 LV and/or RV sites in 10 pigs and during atrial pacing from the endo- and epicardium at 211 ± 54 LV and RV sites in additional 10 pigs. Local activation time (AT), MAP duration (MAPd) and end-of-repolarization time (EOR) were calculated at each site and 3-dimensional maps of AT, EOR and MAP duration on the endo- and epicardium were obtained. LÄS MER

5. 9. T-vector and T-loop morphology analysis of ventricular repolarization in ischemic heart disease

   Författare :Aigars Rubulis; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :;

   Sammanfattning : Background: Sudden cardiac death (SCD) is responsible for about half of all cardiovascular deaths in the western world. Heterogeneous ventricular repolarization (VR) is a common denominator in the genesis of malignant ventricular arrhythmias responsible for SCD and the presence of coronary artery disease (CAD) is an aggravating factor. LÄS MER

7. 10. Cardiac memory studies in two human models

   Författare :Liliane Wecke; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :Cardiac memory; repolarization; pacing; WPW ablation;

   Sammanfattning : Background: Cardiac memory is a form of electrical remodeling of the ventricles, where the T vector follows ("remembers') a previously altered QRS vector. On the electrocardiogram (ECG), it presents as T-wave inversions. LÄS MER