In cardiology, T wave alternans (TWA) is a periodic beat-to-beat variation in the amplitude or shape of the T wave in an electrocardiogram (ECG or EKG). TWA was first described in 1908. At that time, only large variations ("macroscopic" TWA) could be detected.

Non-invasive measurement of beat-to-beat alternation of the electrocardiographic T-wave, referred to as T-wave alternans (TWA), is an important marker of risk for sudden cardiac death (SCD). Is this relationship a mere association or is TWA mechanistically linked to SCD?

T-wave alternans (TWA) refers to periodic beat-to-beat variability in the timing, shape, and/or amplitude of T-waves on the surface electrocardiogram (ECG) [1,2]. TWA therefore reflects sudden changes in temporal heterogeneity in ventricular repolarization, which is an important mechanism underlying reentrant arrhythmias [3,4].

Microvolt T-wave alternans (TWA), characterised as beat-to-beat fluctuation of T-wave amplitude and morphology, is an electrophysiological phenomenon associated clinically with impending ventricular arrhythmias and is an important marker of arrhythmia risk.

T-wave alternans, a manifestation of repolarization alternans at the cellular level, is associated with lethal cardiac arrhythmias and sudden cardiac death.

Mar 31, 2009 · T-wave alternans is a beat-to-beat alternation in the repolarization cycle of the heartbeat. It can be observed in the electrocardiogram (ECG) as a difference in the amplitude and morphology of the ST-segment and/or the T wave among successive odd and even beats in an ABAB pattern (Figure).

T-wave alternans, an integral component of congenital long QT syndrome, is a phenomenon of beat-to-beat variability in T-wave amplitude, morphology, and sometimes polarity that can trigger life-threatening ventricular arrhythmias.

Jan 17, 2006 · T-wave alternans (TWA) reflects beat-to-beat fluctuations in the electrocardiographic T-wave, and is associated with dispersion of repolarization and the mechanisms for sudden cardiac arrest (SCA).

It discusses the electrocardiographic phenomenon of T-wave alternans (TWA) (i.e., a beat-to-beat alternation in the morphology and amplitude of the ST- segment or T-wave). This statement focuses on its physiological basis and measurement technologies and its clinical utility in stratifying risk for life-threatening ventricular arrhythmias.

We review the contemporary understanding of the pathophysiology of repolarization alternans and present a perspective on the use of T-wave alternans (TWA) as a risk stratification marker of malignant ventricular arrhythmias.