OBJECTIVE The aim of the present study was to evaluate the effect of clinical hypothyroidism on cardiovascular autonomic function and ventricular repolarization. DESIGN AND METHODS We studied 31 patients (22 females and 9 males; mean age 53.6+/-11.8 years) with overt hypothyroidism (TSH=56.2+/-14.7 microU/ml, low free thyroxine (T4), free tri-iodothyronine (T3)) and 31 euthyroid controls, to ...

BACKGROUND Myocardial ischemic electrophysiological alterations are associated with the generation of reactive oxygen species. However, electrophysiological effects of antioxidants are unclear. Our objective was to determine the effects of the antioxidant echinochrome on ventricular repolarization in a feline model of 30-min ischemia. METHODS AND RESULTS Activation-recovery intervals were mea...

Previous studies assessing effect of ischemia on ventricular repolarization are mostly directed toward patients with coronary artery disease (CAD); however, similar reports on cardiac syndrome X (CSX) are scarce. Whether microvascular dysfunction of CSX and ischemia induced by CAD produce comparable effect on ventricular repolarization is unclear and deserve further studies. In the present stud...

Introduction: Coronavirus disease 2019 (COVID-19) has been associated with cardiac arrhythmias. Several electrocardiographic markers have used to predict the risk of arrhythmia in patients COVID-19. We aim investigate (ECG) ventricular repolarization indices COVID-19.
 Methodology: performed a comprehensive systematic literature search from PubMed, EuropePMC, SCOPUS, Cochrane Central Datab...

Purpose: It is thought that arrhythmias are responsible for sudden deaths in patients with mitral valve prolapse (MVP). QT intervals may predict malignant arrhythmia potential in these patients. The aim of the present study is to assess QT variables in patients with MVP. Methods : We studied 46 patients with non-rheumatic, uncomplicated and isolated MVP and 25 healthy control subjects. All indi...

Diabetic autonomic neuropathy (DAN) is the least recognized and understood complications of diabetes despite its significant negative impact on survival and quality of life in people with diabetes. QT dispersion in a routine Electrocardiogram (ECG) is a useful marker to identify Type 2 diabetes mellitus (T2DM) patients with a high mortality risk. Therefore this study was undertaken to assess th...

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...