[Concept of activation recovery interval and clinical usefulness of body surface recovery time and recovery time isochrone map].

Several experimental studies have suggested that activation recovery interval (ARI), i.e., the interval between the minimum dV/dt of the QRS and the maximum dV/dt in the ST-T segment on unipolar electrograms, is correlated closely with the transmembrane action potential duration. The ARI can be measured from numerous electrograms recorded simultaneously to provide spatial distribution data on local ventricular recovery. On the other hand, recovery time (RT), i.e., the interval between QRS onset and the time of maximum dV/dt in the ST-T segment, is used to estimate dispersion of ventricular repolarization. In this review article, clinical usefulness of RT and RT ischrone map measured by body surface mapping is outlined in normal subjects and some clinical settings.