Studies in animals have shown that drug-induced action potential prolongation with class III antiarrhythmic agents increases with slow pacing rates. We studied the physiological rate dependence of sotalol effects on ventricular repolarization, measured as QT interval duration on the surface electrocardiogram at rest and during a maximal exercise test, in 10 normal volunteers. In a randomized, c...

A 12-year-old girl presented with an acute confusional state and a 2-year history of weight loss, anxiety, agitation and recurrent fever. Thyroid function tests confirmed severe hyperthyroidism, and a diagnosis of thyroid storm was made (Burch and Wartofsky score=75). ECG showed a prolonged QTc interval of 506 ms. Acute treatment for thyroid storm consisted of Lugol's iodine, prednisolone, carb...

BACKGROUND QT prolongation on the surface ECG is associated with sudden cardiac death. The cause of QT prolongation in ischaemic heart disease (IHD) patients remains unknown, but may be due to a complex interplay between genetic factors and impaired systolic and/or diastolic function through as yet unexplained mechanisms. It was hypothesised that QT prolongation before elective coronary angiogr...

Background Pulmonary hypertension (PH) in congenital heart disease affects the patient’s prognosis. Prolonged QRS and QTc intervals in ECG may intensify life-threatening dysrhythmia in patients. We aimed to investigate the correlation between QRS, QTc, and JTc intervals prolongation in ECG with PH in Congenital Heart Disease (CHD) patients. Mate...

OBJECTIVES This study sought to investigate whether prolongation of the heart rate-corrected QT (QTc) interval is a risk factor for sudden cardiac death in the general population. BACKGROUND In developed countries, sudden cardiac death is a major cause of cardiovascular mortality. Prolongation of the QTc interval has been associated with ventricular arrhythmias, but in most population-based s...

BACKGROUND AND OBJECTIVES Prolonging of the corrected QT interval (QTc) has been reported after cardiac surgery in some studies. However, there have not been many studies on infant open cardiac surgery for ventricular septal defect (VSD) repair. This study was performed to define the changes in QTc and to find related post-surgery factors in this patient group. SUBJECTS AND METHODS From 2008 ...

BACKGROUND Acute cerebral events play an important role in generating autonomic imbalance especially cardiac rhythm disturbances. This forms the basis of significant lethal abnormalities of heart rate and rhythm like QTc prolongation, ventricular fibrillation, asystole, and ultimately death. This study was conducted to determine the frequency of QTc prolongation in patients presenting with acut...