[Pathophysiologic relevance and prognostic value of QT dispersion].

Dispersion of ventricular repolarization measures heterogeneity of repolarization within a given heart. Its importance for the genesis of ventricular arrhythmias has been demonstrated in many experimental studies. The dispersion of the QT interval from the surface ECG (defined as the range of measurable QT intervals within the 12 leads) is a useful diagnostic tool to assess dispersion of ventricular repolarization noninvasively. QT dispersion has therefore been assessed in various patients populations prone to ventricular arrhythmias. The clinical value of QT dispersion in patients with the congenital or acquired long QT syndrome has been clearly demonstrated. In other populations, such as postinfarction patients, patients with congestive heart failure or patients with ventricular tachycardia or ventricular fibrillation, determination of QT dispersion is probably not of clinical value.