Background: Although QT prolongation is associated with increased risk of torsade de pointes (TdP), the precise relationship is not well defined. Aim: To evaluate the performance of a QT nomogram in assessing the risk of TdP from QT– RR combinations. Design: Systematic review. Methods: We systematically searched MEDLINE/ EMBASE for cases of drug-induced TdP. Controls were patients taking non-ca...

Background: Cirrhosis as the final stage of progressive fibrosis of liver can affect other organs such as lungs, kidneys and heart. "Cirrhotic cardiomyopathy" involves the electrophysiological abnormalities such as QT interval prolongation. We assessed correlation between corrected QT interval prolongation and severity of cirrhosis based on Child Classification in each ECG lead. ...

background: qt interval parameters have been suggested as a predictor of lethal arrhythmia and mortality in patients with myocardial infarction. the aim of the present study was to compare the value of qt interval indices in patients presenting with non-st-segment elevation myocardial infarction (nstemi) between a group of patients with type 2 diabetes mellitus and a nondiabetic group of patien...

in this paper, we study the chebyshev centres of bounded subsets of normed spaces and obtain a norm inequality for relative centres. in particular, we prove that if t is a remotal subset of an inner product space h, and f is a star-shaped set at a relative chebyshev centre c of t with respect to f, then llx - qt (x)1i2 2 ilx-cll2 + ilc-qt (c) 112 x e f, where qt : f + t is any choice function s...

Long QT intervals in the ECG have long been associated with sudden cardiac death. The congenital long QT syndrome was first described in individuals with structurally normal hearts in 1957.1 Little was known about the significance of a short QT interval. In 1993, after analyzing 6693 consecutive Holter recordings Algra et al concluded that an increased risk of sudden death was present not only ...

Prolonged QT interval is suggested to indicate an increased risk of sudden cardiac death in certain clinical conditions such as diabetes mellitus. We investigated whether the individual QT interval is an indicator of an autonomic state. An ambulatory 24-hour ECG was recorded in 53 subjects from different clinical backgrounds. Power spectral components of heart rate variability (HRV) and the QT ...

were performed before and after oral propranolol administration, 160 mg daily for 2 days. During the 24-hour control period, the QT was always shorter than the QS2 (from 14 ± 3 to 19 ± 4 msec,p < 0.01), while during isoproterenol infusion the QT was always greater than the QS2 (from 28 ± 5 to 34 ± 5 msec, p < 0.01). Group 2 included 26 patients in whom 24-hour urinary epinephrine (E) and norepi...

BACKGROUND AND PURPOSE We studied the relationship of heart rate-corrected QT interval with subclinical atherosclerosis, as determined by ultrasonographic measurement of carotid intima-media thickness (IMT) in nondiabetic subjects in the Insulin Resistance Atherosclerosis Study (IRAS). Prolonged heart rate-corrected QT interval is an unfavorable prognostic factor of cardiovascular morbidity and...

A prolonged QT interval is an important risk factor for ventricular arrhythmias and sudden cardiac death. QT prolongation can be caused by drugs. There are multiple risk factors for drug-induced QT prolongation, including genetic variation. QT prolongation is one of the most common reasons for withdrawal of drugs from the market, despite the fact that these drugs may be beneficial for certain p...

QT dispersion was originally proposed to measure spatial dispersion of ventricular recovery times. Later, it was shown that QT dispersion does not directly reflect the dispersion of recovery times and that it results mainly from variations in the T loop morphology and the error of QT measurement. The reliability of both automatic and manual measurement of QT dispersion is low and significantly ...