A patient with "atrial torsades de pointes"

A patient with long QT syndrome and a history of palpitations underwent ele ctrophysiologic study, Runs of polymorphic self-terminating atrial tachyarr hythmias were easily induced and occurred spontaneously several times. Atri al monophasic action potential (MAP) durations were prolonged at short paci ng cycle lengths. Premature high right atrial extrastimuli prolonged MAP du rations in the low right atrium, resulting in an inverse electrical restitu tion curve, and increased dispersion of repolarization, MAP morphology show ed gradually increasing early afterdepolarizations. When the arrhythmia was initiated, a new action potential reproducibly emerged from these afterdep olarizations. To the knowledge of the authors, this is the first reported c ase of "atrial torsades de pointes" in a patient.