EN
A 27-year old man experienced recurrent syncope with prodromal palpitations and resultant injury. The features of these episodes suggested a potentially neurally-mediated mechanism. Head-up tilt test revealed the postural orthostatic tachycardia syndrome (POTS). Within the first minutes of upright posture during the total head-up tilt testing, a heart rate increase of >30 beats/min and to a maximum of 150 beats/min was documented in the patient. At the end of passive tilting, the patient lost consciousness in the absence of hypotension while in sinus rhythm of 140 bpm. The 12-lead ECG and electrophysiological study showed no abnormalities. The patient received a beta-adrenergic blocker, a selective central imidazoline receptor agonist and psychiatric therapy, resulting in only a short-term improvement.