POLYMORPHIC VENTRICULAR-TACHYCARDIA INDUCED DURING TILT-TABLE TESTINGIN A PATIENT WITH SYNCOPE AND PROBABLE DYSFUNCTION OF THE SINUS NODE

We present a case of life-threatening arrhythmia occurring during tilt table testing in a 44-year-old man with syncope. Polymorphic ventricu lar tachycardia occurred while the patient was tilted up under the int ravenous infusion of isoproterenol (2 mu g/min). No ischemia, QTc prol ongation, or electrolyte abnormality preceded this event. The arrhythm ia was not induced by programmed ventricular stimulation or exercise t esting. Based on electrophysiological and clinical data, the diagnosis of sick sinus syndrome was entertained.