Ventricular repolarization wave variations during the amiodarone treatment course

Area of Science:

• Cardiology
• Electrophysiology

Background:

• Ventricular arrhythmias and atrial fibrillation pose significant clinical challenges.
• Amiodarone is a widely used antiarrhythmic drug, but its effects on ventricular repolarization require detailed assessment.

Purpose of the Study:

• To evaluate changes in ventricular repolarization parameters during amiodarone treatment.
• To assess the impact of amiodarone on QT interval, TpTe, and repolarization dispersion.

Main Methods:

• Seventy-eight patients with ventricular arrhythmias or atrial fibrillation received intravenous and oral amiodarone.
• Measurements of heart rate, QT, QTc, QTd, QTcd, TpTe, TpTe-c, TpTe-d, TpTe/QT, and QTp were taken on multiple days during treatment.

Main Results:

• Amiodarone effectively controlled arrhythmias in 91% of patients.
• Significant reductions in heart rate were observed by day 7, with a nadir on day 14.
• QT and QTp intervals were prolonged throughout treatment, with TpTe showing transient prolongation between days 7 and 14.

Conclusions:

• Amiodarone effectively manages arrhythmias by reducing heart rate and prolonging QT and QTp intervals.
• The drug causes transient prolongation of TpTe but does not significantly alter repolarization dispersion.
• TpTe/QT ratio is a more reliable marker for ventricular transmural repolarization dispersion than TpTe alone.