Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 18 of 18 for “"QT interval"”.
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QT-interval adaptation to changes in autonomic balance
… (HRV). HRV studies the variability of the RR intervals in the ECG; these intervals are modulated by the autonomic influence on the periodicity of the the heart's pacemaker, the sino-atrial node. The autonomic influence at this level is dominated by the parasympathetic nervous system. In order …
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The Effects of Glucose Tolerance, Hypertension, and Race on Heart Rate Variability, QT Interval Duration, and Left Ventricular Hypertrophy in Overweight-Obese Adolescents
… risk factors of heart rate variability (HRV), QT corrected (QTc) Interval duration, and Cornell voltage measures for left ventricular hypertrophy (LVH) to body mass index (BMI), relative body mass index (RBMI), and blood pressure (BP) measures, and to examine the effects of impaired glucose …
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A case control study to identify and explore associations with sudden death and medications that can prolong the QT interval on the electrocardiograph.
… use of drugs that can cause prolongation of the QT interval on the electrocardiograph are associated with an increased risk of sudden death from cardiac arrhythmia. Methods: A community based, matched case control study used post mortem and primary care datasets. Cause of death was most likely …
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The Association of Single Nucleotide Polymorphisms (SNPs) in the Nitric Oxide Synthase 1 Adaptor Protein Gene (NOS1AP) and the QT Interval Duration Across Race/Ethnicity in Adults Without Clinical Cardiovascular Disease
Introduction: The QT interval is an independent risk factor for sudden cardiac death (SCD). A genome wide association study (GWAS) identified NOS1AP variants associated with QT, which has been replicated in predominantly Caucasian populations. The MESA study provides an opportunity to study single …
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QT variability calculation using a template matching algorithm and power spectral analysis
ECG interval measurement and variability analysis has proven to be a useful tool in investigating autonomic nervous system function. Traditionally, the R to R interval has been the thrust of research conducted in this field. QT variability is another topic on which little research has been done. …
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Intratracheal instillation of silver nanoparticles exacerbates cardiac ischemia/reperfusion injury in male sprague-dawley rats
… cardiac I/R surgery for heart rate (HR), PR interval, and QT interval. To test the impact of silver ion exposure on cardiac I/R injury we administered 200 ul of 0.01 mg/mL, 0.1 mg/mL, or 1 mg/mL silver acetate (AgAc) and induced cardiac I/R 24 hours later. Intratracheal instillation of AgNP …
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The Development Of An Evidence-Based Anti-Emetic Tool For The Management Of Post-Operative Nausea And Vomiting In Patients At High Risk For Qt Prolongation And Patients Taking Neurotransmitter Modulating Medications
… for patient populations at risk for prolonged QT interval or patients who are routinely taking neurotransmitter modulating medications. Safe practice recommendations exist but are scattered throughout the literature. The goal of this project was to develop a tool for care providers that …
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Automatic detection of qt and related intervals
… of the Q wave, Tmax afld the Tend to measure the intervals such as QT, QT corrected (QTc), RT, QT_{max} and RT_{max} respectively. The second section deals with the analysis of different variabilities including heart rate variability (HRV), QT, QTc, RT, QT_{max} and RT_{max}. Using the R wave …
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Mapping Ligand Binding Sites in hERG1 Channel with Biomolecular Simulations
… of various classes of drugs which can cause QT interval prolongation. The consequent cardiac arrhythmia, known as acquired long QT syndrome, has led to the withdrawal of several approved drugs and a mandatory preclinical stage safety assessment for hERG1 blockade. However, cardiotoxicity …
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Population pharmacokinetic and pharmacodynamic modelling to improve tuberculosis treatment
… the effect of clofazimine concentration on QT interval prolongation. We investigated alternative dosing regimen to optimise clofazimine treatment and suggested that a 2-week loading dose may support treatment shortening by safely enabling more rapid attainment of efficacy targets. For …
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Febrile Temperature Facilitates Degradation of Human Ether-a-Go-Go-Related Gene (hERG) Channels
… or drug-mediated effects can lead to long QT syndrome (LQTS), predisposing affected individuals to cardiac arrhythmias, syncope, and sudden death. Recently, studies have reported roles for fever in triggering QT prolongation and life-threatening cardiac arrhythmias in patients with …
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The Pattern of Ventricular Repolarization during Therapeutic Hypothermia
… known to cause prolongation of the corrected QT interval (QTc). QTc prolongation can cause polymorphic ventricular tachycardia (VT) and ventricular fibrillation (VF). The interval from the peak to the end of the T wave (TpTe) indicates myocardial transmural dispersion of repolarization (TDR) …
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Arrhythmogenic potential of alpha-adrenoceptor stimulation in the rat heart
… the arrhythrnogenic effect of methoxamine. The QT interval increased with alpha₁-adrenoceptor stimulation, this being an indirect index of prolongation of the action potential duration. The arrhythmogenic action of methoxamine was associated with a positive inotropic effect. Prazosin 10⁻⁸M (an …
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Modelling multivariate longitudinal outcomes and time-to-event data
… i.e., ECG rate (ECGrate), ECG PR interval (ECGpri), ECG corrected QT interval (ECGqtc), and ECG QRS duration (ECGqrsd) on survival outcomes, death, constriction, and composite outcome (death, constriction, or cardiac tamponade, whichever occurs first) in the investigation of the …
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Automated Cardiac Rhythm Diagnosis for Electrophysiological Studies, an Enhanced Classifier Approach
… tachycardias. Temperature, accelerometry and QT interval were assessed as features by a comparison of algorithm performances with each feature removed and found not to affect classification performance. An evaluation showed 10 beat analysis performed better than 5 beat analysis. CONCLUSIONS …
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Electrocardiographic Consequences Of Electrical And Anatomical Remodeling In Diabetic And Obese Humans
… and measured BSPs with obesity. Although QT interval prolongation found in simulated BSPs was not seen in the ECGs recorded from the obese diabetic subject, QT dispersion(QTd) was found increased in diabetic in both simulated and measure ECGs. Obviously, no statistical conclusions can be …
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Global sequence and dispersion of ventricular repolarization: In vivo validation of non-invasive parameters using monophasic action potential mapping technique
… 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 …
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Non-invasive detection of hyperglycaemia in type 1 diabetic patients using electrocardiographic signals
… such as increased heart rate and prolongation of QT interval in hypoglycaemia, whereas hyperglycaemia was related to reduced heart rate variability. By using these findings in hypoglycaemia, researchers have developed an effective and sensitive system to detect hypoglycaemia non-invasively. These …