Intermittent Preexcitation and Electrotonic Modulation of Repolarization as a Cause of Macroscopic T Wave Alternans
Alterations in ventricular depolarization are recognized to lead to inverted T-waves which manifest once the ventricular activation returns to normal. This phenomenon referred to as ‘T-wave memory’ or ‘electrotonic modulation’ may be caused by several clinical conditions producing a shift in ventricular depolarization. Currently, T wave alternans (TWA), either macroscopic or microscopic refers to the beat to beat alteration in the repolarization heterogeneity that repeats with every other beat without changes in the QRS complex. We present the case of a 43-year old man with symptomatic intermittent pre-excitation who underwent 24-hour Holter monitoring revealing TWA secondary to electrotonic modulation. It is assumed that this phenomenon does not carry any prognostic significance.
