Paroxysmal atrial tachycardia; may progress to congestive failure in prolonged episodes or with underlying heart disease. Condition is also associated with Wolff-Parkinson-White syndrome and biliary tract pathology. Onset occurs in childhood; boys affected almost exclusively. Treatment is digitalis, phenylephrine, Valsalva and Mller maneuvers, and unilateral carotid sinus stimulation.