BACKGROUND The risk factors for ventricular arrhythmias in patients with coronary vasospasm have not been identified. We evaluated QT dispersion in patients with vasospastic angina and its relation to susceptibility to ventricular arrhythmias during myocardial ischemia and reperfusion. METHODS AND RESULTS We assessed the corrected QT (QTc) dispersion before induction of coronary artery spasm ...

OBJECTIVES Ivabradine is the first specific heart rate-lowering agent that has completed clinical development for stable angina pectoris. The aim of the present study was to investigate the effects of ivabradine therapy on P-wave duration, dispersion and QT duration, dispersion in coronary artery disease patients. METHODS AND RESULTS The study population consisted of 21 patients with CAD who ...

BACKGROUND Altered cardiac repolarization is a risk factor for sudden cardiac death and seems to be increased in chronic obstructive pulmonary disease (COPD) patients. OBJECTIVE Lung volume reduction surgery (LVRS) has been shown to improve breathing mechanics and lung function in patients with severe COPD and emphysema and possibly also improve altered cardiac repolarization. METHODS Thirt...

OBJECTIVE Glycemic variability (GV) is a new term with the episodes of hyper and hypoglycemia in diabetic patients. Both prolonged QT interval and QTd are potential risk factors for malignant ventricular arrhythmias affecting the mortality of different groups of patients including diabetes mellitus. In this study, we aimed to evaluate if the glucose variability increasing the QTc interval and Q...

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...

AIM To investigate ventricular arrhythmias in children with primary mitral valve prolapse and to evaluate its relation with QT length, QT dispersion, autonomic function tests and heart rate variability measurements. MATERIAL AND METHODS Fourty two children with mitral valve prolapse and 32 healthy children were enrolled into the study. Twelve-lead electrocardiograms, autonomic function tests,...

OBJECTIVES The purpose of this study was to test the hypothesis that the extent of drug-induced QT prolongation by dofetilide is greater in sinus rhythm (SR) after cardioversion compared with during atrial fibrillation (AF). BACKGROUND Anecdotes suggest that when action potential-prolonging antiarrhythmic drugs are used for AF, excessive QT prolongation and torsades de pointes (TdP) often occ...

QT interval parameters have been associated with left ventricular hypertrophy (LVH) in hypertensive patients. The aim of this study is to assess this relationship in resistant hypertension and, in particular, to evaluate whether any QT interval parameter could provide additive information for LVH beyond that obtained from the best electrocardiographic voltage criterion. In a cross-sectional stu...

Background and Objectives: The QT interval (QTi) and QT dispersion (QTd), which represent the myocardial electrical heterogeneity of repolarization, were studied to recognize the differences between normal controls (n=32) and stable angina patients (n=78). Subjects and Methods: During the treadmill exercise test, standard 12 lead Electrocardiogram (ECG) was obtained at every stage, with the QTi...