Sökning: "Action potential duration"

Visar resultat 1 - 5 av 22 avhandlingar innehållade orden Action potential duration.

  1. 1. 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; 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

  2. 2. Mechanism of Action of the Antiarrhythmic Agent AZD7009

    Författare :Frida Persson; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    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

  3. 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; 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

  4. 4. 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; 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. 5. Sequence and dispersion of repolarization of the right atrium: Implications of repolarization disturbance in atrial fibrillation

    Författare :Zhen Li; Kardiologi; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Kardiovaskulära systemet; Cardiovascular system; electroanatomical mapping; monophasic action potential; atrial fibrillation; repolarization; dispersion;

    Sammanfattning : To explore the global sequence and dispersion of repolarization of the right atrium, monophasic action potentials (MAPs) were sequentially recorded from the right atrium using an electroanatomical mapping (CARTO) system in 10 healthy pigs and in 10 patients with (n=6) and without (n=4) paroxysmal atrial fibrillation (PAF) during sinus rhythm, or using two MAP recording catheters in 30 patients with or without PAF (n=15 each) during sinus rhythm, pacing, and programmed stimulation. The dispersion of activation time (AT), repolarization time (RT) and MAP duration (MAPd) were analyzed. LÄS MER