A 40 years old male with history of unexplained recurrent presyncope and palpitation episodes referred to cardiology department. Patient had no past medical history. Subsequently, electrophysiology study was performed to detect any underlying atrioventricular nodal disease or inducible tachyarrhythmias. During this period, 1.0 mg of atropine was injected intravenously to performed stimulation and patient suddenly developed polymorphic ventricular tachycardia that could not be terminated with overdrive pacing. Ventricular tachycardia was terminated spontaneously, two minutes later. J Clin Exp Invest 2014; 5 (3): 449-451