The Use of Transcranial Doppler during Tilt Table Testing in Children Presenting with Syncope

Abstract

Childhood syncope is common, and there are three categories of causes of syncope: noncardiovascular pseudosyncope, cardiovascular syncope, and neurally mediated syncope. Tilt table testing has become a valuable tool in the evaluation for the cause of syncope in children. Adding transcranial Doppler (TCD) to the tilt table test to monitor the middle cerebral arteries (MCA) adds valuable information about the cerebral blood flow during a syncopal episode and can help the physician differentiate between the various causes of syncope. Three children with frequent syncopal episodes were evaluated using tilt table testing with multimodal monitoring, including TCD. One child, during her syncopal episode, had an increase in blood pressure, heart rate, and MCA flow velocities. This finding was consistent with noncardiovascular pseudosyncope, and she was sent for psychiatric treatment. The other two patients had hypotension, bradycardia, a significant decrease in MCA flow velocities, and an increase in pulsatility indices. Additionally, one of them experienced a 6-sec period of asystole. Both were diagnosed with neurally mediated syncope and were placed on fludrocortisone and a water and salt regimen.