Resetting and entrainment of reentrant arrhythmias: part II: informative content and practical use of these responses.

This paper is the second part of a review of the phenomena of resetting and entrainment of reentrant arrhythmias. It describes the practical and clinical uses of resetting and entrainment, including the results of a variety of studies for these purposes. Given the amount of information generated, it is out of the scope of this review to comment in detail about each of the published studies. We rather present the basis for each described clinical use and for each type of arrhythmia in which these phenomena have been used with illustrative examples. The review covers: resetting response patterns; resetting/entrainment and termination; resetting/entrainment, fusion, and reentry; analysis of the postpacing interval; concealed entrainment; resetting/entrainment as an aid in the differential diagnosis among different arrhythmic mechanisms; usefulness of these phenomena in arrhythmic mechanisms other than macrorreentry. Finally, we make some comments about the recent use of these phenomena and propose two new criteria for entrainment recognition.