Sökning: "cardiac action potential"

Visar resultat 1 - 5 av 21 avhandlingar innehållade orden cardiac action potential.

1. 1. 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. 2. Cellular electrophysiological modulation in chronic atrial fibrillation - Studies with magnesium and GIK solution

   Författare :Max Ingemansson; Lunds universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Action potential duration; Atrial cycle length; Atrial remodelling; Autonomic nervous system; AV-nodal; Conduction velocity; GIK; Magnesium; Resting membrane potential.; Refractoriness; Atrial fibrillation; Cardiovascular system; Kardiovaskulära systemet;

   Sammanfattning : Although chronic atrial fibrillation (CAF) is the most common sustained cardiac arrhythmia in man, the mechanisms involved in its progressive course are still not fully understood. Recent studies have verified an electrical remodelling of the atrial myocardium that may be responsible for the electrophysiological disturbances known to exist in the fibrillating atria. LÄS MER

4. 3. Ventricular rotation and the rotation axis : a new concept in cardiac function

   Författare :Ulf Gustafsson; Anders Waldenström; Per Lindqvist; Alan Fraser; Umeå universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Left ventricular function; right ventricular function; rotation; twist; rotation axis; transition plane; ischemia; speckle tracking echocardiography; Cardiology; Kardiologi; Cardiology; kardiologi;

   Sammanfattning : Background: The twisting motion of the left ventricle (LV), with clockwise rotation at the base and counter clockwise rotation at the apex during systole, is a vital part of LV function. Even though LV rotation has been studied for decades, the rotation pattern has not been described in detail. LÄS MER

5. 4. Mechanism of Action of the Antiarrhythmic Agent AZD7009

   Författare :Frida Persson; Göteborgs universitet; []
   Nyckelord :atrial fibrillation; antiarrhythmic drug; IKr; IKur; Ito; IKs; IKACh; INa; ICaL; cardiac action potential; early afterdepolarisation;

   Sammanfattning : Atrial fibrillation (AF) is the most common tachyarrhythmia in the adult population and is a major cause of morbidity and mortality. AF can be terminated and sinus rhythm restored by prolonging the action potential duration (APD) and the refractory period. LÄS MER

7. 5. 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