The Postural Orthostatic Tachycardia Syndrome: Clinical and Transcranial Doppler-Tilt Test Findings of Two Cases

Abstract

The postural orthostatic tachycardia syndrome (POTS) is characterized by disabling fatigue, dizziness, lightheadedness, tachycardia and presyncopal symptoms on standing up. Transcranial Doppler (TCD)-tilt table testing is the major diagnostic tool and the findings ofa heart rate increase of 30 or more beatslminute, a drop in cerebral flowvelocity and no significant orthostatic hypotension strongly supports the diagnosis . Two female patients aged 26 and 49, who attended our neurological outpatient clinic complaining of dizziness, palpitation, fatigue and lightheadedness on standing are presented. The TCD-tilt test revealed normal blood pressure changes, a drop of more than 20% in cerebral flow velocities anda heart rate increase of more than 30 beatslminute. Both patients complained of dizziness, fatigue and palpitation 10 minutes after erect posture. The patients were diagnosed as POTS and were started onpropranolol 40 mglday which markedly reduced their complaints.