The U wave in the electrocardiogram. More than an academic curiosity

The electrocardiographic U wave was describe by Einthoven in 1903. Despite the time elapsed since its description the electrophysiological basis underlying the genesis of the U wave has not been precisely elucidated and several hypothesis have been proposed. Proper evaluation and interpretation of the U wave is useful to the clinician because it is a marker of heart disease. The aim of this paper is to review current concepts related to U wave,...