A case of orthostatic tachycardia syndrome presenting with panic attack during tilt table testing.

A 26-year-old woman experienced syncope on standing 2-3 times a year for more than 15 years. The attack was typically associated with palpitations and frequently accompanied by a feeling of intense fear. The patient underwent head-up tilt table testing at 70° for 40 min to determine the cause of the syncope. The tilt test results suggested that the etiology of the syncope was orthostatic tachycardia syndrome complicated by panic attack-associated hypocapnic hyperventilation, which presumably caused a greater degree of deep cerebral hypoperfusion than would be expected with orthostatic tachycardia syndrome alone, ultimately leading to the patient's symptoms, including syncope. In conclusion, monitoring the ventilation and/or arterial CO(2) level during head-up tilt table testing is occasionally required when evaluating patients with postural syncope.