Mitral valve prolapse (MVP) is a relatively frequent valvular abnormality. In both children and adults with MVP, an increased incidence of ventricular arrhythmias has been reported. QT dispersion, defined as the difference in duration between the longest QT interval and the shortest one, for a given set of electrocardiographic leads has been proposed as a sign of regional difference in card...

Background: Passive cigarette smoking is a known cause of a variety of diseases.  However, most of the studies done in this field have focused on its chronic effects on human health.  Studies considering the acute effect of smoking on QT dispersion, on the other hand, with its known predictive role in the occurrence ventricular arrhythmia and sudden cardiac death are sparse. Objectives: This st...

background anthracyclines are important components of many chemotherapeutic protocols. the present study aimed to evaluate the repolarization changes in electrocardiography (ecg) which may predict drug induced arrhythmia. materials and methods in this cross-sectional study, the recorded ecgs were assessed for qt dispersion (qtd), qt corrected dispersion (qtcd), t peak to tend dispersion (tped),...

Abnormal left ventricular structure and function as in, for example, left ventricular hypertrophy or chronic heart failure, is associated with sudden cardiac death and, when the ejection fraction is depressed, with prolongation of the QT interval. The dependence on heart rate of QT interval prolongation in these conditions, and the relationship of any abnormalities either to deranged autonomic ...

This study investigated beat-to-beat QT variability in patients with panic disorder and depression, and normal control subjects using an automated algorithm to compute QT intervals. An increase in QT variability appears to be associated with symptomatic patients with dilated cardiomyopathy and also with an increased risk for sudden death. QT(vm) (QT variability normalized for mean QT interval) ...

Evaluating whether a new medication prolongs QT intervals is a critical safety activity that is conducted in a sensitive animal model during non-clinical drug development. The importance of QT liability detection has been reinforced by non-clinical [International Conference on Harmonization (ICH) S7B] and clinical (ICH E14) regulatory guidance from the International Conference on Harmonization....

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...