Os efeitos da metformina sobre a dispersão do intervalo QT e QTc de ratos diabéticos

Abstract

SummaryBackground: 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 metformin on glycemia and cardiovascular risk markers.

Reduced N‐Type Ca 2+ Channels in Atrioventricular Ganglion Neurons Are Involved in Ventricular Arrhythmogenesis

“…VF was defined as rapid, irregular QRS complexes. QT and QTc intervals as well as dispersions (QTd and QTcd) were calculated from ECG recordings using LabChart 7 software 27. A QTc interval was calculated by the Bazett formula (QT/$\sqrt{\text{RR}}$, where RR is the RR interval).…”

“…A QTc interval was calculated by the Bazett formula (QT/$\sqrt{\text{RR}}$, where RR is the RR interval). As an index of the spatial dispersion of the ventricular repolarization, QTd and QTcd were calculated by equations: QTd=QT max −QT min and QTcd=QTc max −QTc min , where QT max and QTc max are the maximum QT interval and the maximum QTc interval; QT min and QTc min are the minimum QT interval and the minimum QTc interval 27. The T‐peak to T‐end interval (Tpe), another marker of transmural dispersion of the ventricular repolarization, was calculated from ECG recordings to serve as an ECG marker of ventricular arrhythmia 28…”

Correlation of Ventricular Arrhythmogenesis with Neuronal Remodeling of Cardiac Postganglionic Parasympathetic Neurons in the Late Stage of Heart Failure after Myocardial Infarction

“…VF was defined as rapid, irregular QRS complexes. QT and QTc intervals as well as dispersions (QT d and QTc d ) were calculated from ECG recordings using Labchart software (Costa et al, 2008). QTc interval was calculated by Bazett's formula (QT$\sqrt{RR}$, where RR is RR interval; Costa et al, 2008).…”

“…QT and QTc intervals as well as dispersions (QT d and QTc d ) were calculated from ECG recordings using Labchart software (Costa et al, 2008). QTc interval was calculated by Bazett's formula (QT$\sqrt{RR}$, where RR is RR interval; Costa et al, 2008). As an index of the spatial dispersion of the ventricular repolarization, QT d and QTc d were calculated by equations: QT d = QT max − QT min and QTc d = QTc max − QTc min , where QT max and QTc max are the maximum QT interval and the maximum QTc interval; QT min and QTc min are the minimum QT interval and the minimum QTc interval (Costa et al, 2008).…”

“…QTc interval was calculated by Bazett's formula (QT$\sqrt{RR}$, where RR is RR interval; Costa et al, 2008). As an index of the spatial dispersion of the ventricular repolarization, QT d and QTc d were calculated by equations: QT d = QT max − QT min and QTc d = QTc max − QTc min , where QT max and QTc max are the maximum QT interval and the maximum QTc interval; QT min and QTc min are the minimum QT interval and the minimum QTc interval (Costa et al, 2008). T-peak to T-end interval (Tpe), another marker of transmural dispersion of the ventricular repolarization, was calculated to serve as an ECG marker of ventricular arrhythmia (Yan et al, 2003; Antzelevitch, 2007; Yagishita et al, 2015).…”