OBJECTIVE To define the effects of beta(2) adrenergic receptor stimulation on ventricular repolarisation in vivo. DESIGN Prospective study. SETTING Tertiary referral centre. PATIENTS 85 patients with coronary artery disease and 22 normal controls. INTERVENTIONS Intravenous and intracoronary salbutamol (a beta(2) adrenergic receptor selective agonist; 10-30 microg/min and 1-10 microg/min...

QT interval dispersion (QT(d)) reflects inhomogeneity of repolarisation. Delayed cardiac repolarisation leading to the prolongation of the QT interval is a well-characterised precursor of arrhythmias. Obstructive sleep apnoea syndrome (OSAS) can cause cardiovascular complications, such as arrhythmias, myocardial infarction, and systemic and pulmonary hypertension. The aim of this study was to a...

AIMS Torsades de pointes arrhythmias (TdP) occur by definition in the setting of prolonged QT intervals. Animal models of drug induced Long-QT syndrome (dLQTS) have shown higher predictive value for proarrhythmia with beat-to-beat variability of repolarization duration (BVR) when compared with QT intervals. Here, we evaluate variability of QT intervals in patients with a history of drug-induced...

For half a century, the relationship between the QT interval and cardiac arrhythmias has been recognized,1 although attention has focused primarily on prolongation of the QT. The congenital long-QT syndrome (LQTS) was first identified in patients with syncope, aborted sudden death, or family history of cardiac arrest as an association between a prolonged QT interval and development of potential...

These lecture notes provide a basic introduction to the framework of generalized probabilistic theories (GPTs) and sketch reconstruction quantum theory (QT) from simple operational principles. To build some intuition for how physics could be even more general than quantum, I present two conceivable phenomena beyond QT: superstrong nonlocality higher-order interference. Then introduce GPTs, gene...

thalassemia major patients require repeated transfusions of packed cell and their lysis lead to iron deposition especially in the cardiac walls such as septum and posterior wall, so make thickening and cause cardiac disorders. in this case-control study, our object was to appoint if qt and qtc and te dispersions were predictors of cardiac disorders in thalassemia major patients or not. 34 thala...

INTRODUCTION It is believed that an exaggerated blood pressure response (EBPR) to exercise stress test is associated with a higher risk of cardiovascular events. It is also assumed that QT dispersion (QT-d), which was originally proposed to measure the spatial dispersion of ventricular recovery times, may have a relationship to cardiovascular events. The objective of this study was to examine t...

Multiple qt-binomial coefficients and multiple analogues of several celebrated families of related special numbers are constructed in this paper. These higher dimensional generalizations include the first and the second kind of qt-Stirling numbers, qt-Bell numbers, qt-Bernoulli numbers, qt-Catalan numbers and the qt-Fibonacci numbers. Certain significant applications are also studied including ...

BACKGROUND Recent molecular biological investigations have identified abnormal genes in familial forms of long QT syndrome, but in bradycardia dependent acquired long QT syndrome, no such genetic abnormality has yet been identified. OBJECTIVE To investigate the relation between the responses of QT interval to pacing change and to disopyramide. METHODS This study included 13 patients with br...

OBJECTIVE To determine the normal values of QT and QTc dispersion and the effects of sinus arrhythmia on QT dispersion in healthy children. PATIENTS AND SETTING The study was carried out in a university hospital on 372 local schoolchildren (200 male, 172 female), aged seven to 18 years. METHODS The QT and preceding RR intervals of at least one sinus beat were measured manually in a range of...