Sökning: "endocardium"

Visar resultat 1 - 5 av 8 avhandlingar innehållade ordet endocardium.

1. 1. 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

3. 2. Statistical Segmentation and Registration of Medical Ultrasound Data

   Författare :Mattias Hansson; Matematik LTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Registration; Segmentation; Feature descriptor; Statistical image and signal processing; Medical ultrasound; Variational methods; Mixture model; Bayesian; Markov Chain Monte Carlo; Similarity measur;

   Sammanfattning : The interpretation of ultrasonic imagery is typically not straightforward and of quite subjective nature and therefore strongly dependent on the expertise of its users. Thus the development of algorithms which aid in the interpretation of ultrasonic data is a highly relevant topic. LÄS MER

4. 3. 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

5. 4. Modelling of strain tensors in cardiac kinematics

   Författare :Katarina Kindberg; Linköpings universitet; []
   Nyckelord :MEDICINE; MEDICIN;

   Sammanfattning : The heart wall consists of three distinct layers: the inner endocardium, the middle myocardium and the outer epicardium. The myocardium is the functional tissue that endows the heart with its ability to pump blood, and consists primarily of locally parallel muscle fibers. The orientation of these muscle fibers change with position in the wall. LÄS MER

7. 5. Optimal pacing with and implantable pO2 sensor

   Författare :Nils Holmström; KTH; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :;

   Sammanfattning : A goal in modern pacemaker technology is to adapt the timing of stimulation to the metabolic demand and to optimize the hemodynamics of the diseased heart. Because the plasma concentration of mixed venous oxygen is a good indicator of workload and circulation, we developed an implantable coulometric blood oxygen sensor to improve the rate adaptation. LÄS MER