BACKGROUND Several drugs can cause prolonged QT interval, as well as prolonged QT dispersion (QTd) in electrocardiographic (EKG) recordings. QTd may be a potentially sensitive marker of increased risk of cardiac arrhythmias and sudden cardiac death. Metformin is an effective antihyperglycemic agent used in the treatment of diabetes. However, studies have correlated dose-dependent effects of met...

Congenital long QT syndrome (LQTS) is caused by mutations in various cardiac potassium or sodium channel genes, with 6 different genotypes thus far identified. However, it is unknown whether these genotypes can be differentiated by QT variables. The electrocardiograms obtained from 16 patients with a mutation in KCNQ1 (LQT1), 7 patients with a mutation in HERG (LQT2) and 20 control subjects wer...

BACKGROUND Cigarette smoking increases the risk of ventricular fibrillation and sudden cardiac death (SCD). QT dispersion (QTD) is an important predictor of cardiac arrhythmia. The aim of this study was to assess the acute effect of smoking a single standard cigarette containing 1.7 mg nicotine on QT interval and QTD in healthy smokers and nonsmokers. METHODS The study sample population consi...

1. An association has been reported between QT interval abnormalities and cardiovascular autonomic neuropathy in diabetic patients. The QT interval abnormalities reflect local inhomogeneities of ventricular recovery time and may be related to an imbalance in cardiac sympathetic innervation. Sympathetic innervation of the heart can be visualized and quantified by single-photon emission-computed ...

BACKGROUND Patients with chronic heart failure (CHF) have a markedly increased incidence of malignant ventricular arrhythmias. QT dispersion (QTd), defined as the difference between maximal and minimal QT intervals, reflects the regional inhomogeneity of ventricular repolarization dispersion and may mark the presence of malignant ventricular arrhythmias. PURPOSE To determine the effects of ex...

OBJECTIVE To evaluate the cardiotoxicity of LV5FU2 regimen (bolus plus infusional 5-fluorouracil/folinic acid) treatment by non-invasive methods such as echocardiography, plasma troponin I (TnI) level, QT interval and QT dispersion on ECG. METHODS Twenty-two patients with gastrointestinal cancer who received LV5FU2 chemotherapy were evaluated prospectively during 12 cycles of chemotherapy. Pl...

INTRODUCTION AND AIM Sarcoidosis increases inhomogeneity in ventricular repolarization due to the presence of sarcoid granuloma, which significantly correlates with ventricular fibrillation. Various studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (T-peak to T-end [Tpe] interval) may correspond to the transmural dispersion of repolarization an...

Objective: To evaluate repolarization defects and arrhythmogenic predisposition through ventricular markers in patients with subclinical hyperthyroidism (sHT).
 Materials Methods: Patients asymptomatic endogenous sHT healthy participants similar age demographic characteristics were included our study. Laboratory tests echocardiographic evaluations performed. Specific markers,such as QT, QT...