CARDIOVASCULAR ENGINEERING Journal for Extracorporeal Circulation, Assist Devices,Transplantation and Artificial Organs
	Volume 4, 1999, No 1

A Study on Head-up Tilt Test for the Diagnosis of Unexplained Syncope in Children
D. Junbao, M. Zhao, L. Wanzhen, C. Jianjun, J. Jianfeng, Z. Heping

Background: Syncope is one of the common problems in clinical pediatrics. Although intensive examinations have been made for the diagnostic work-up, the cause of recurrent syncope still remains unclear in a large number of patients. In recent years a non-invasive diagnostic measure for the determination of the causes of unexplained syncope, the head-up tilt test, has been established in adult patients. But its sensitivity, specificity and the diagnostic value have insufficiently understood in pediatric cases. The present study was done to investigate the efficacy of the head-up tilt test in the work-up of unexplained syncope in children.

Methods: We studied 42 patients with unexplained syncope and 13 healthy children as controls in the head-up tilt to 60 degrees for 45 minutes. The test was considered positive if syncope or pre-syncope developed in association with hypotension, bradycardia, or both.

Results: The head-up tilt test was positive in 66.7% of patients with unexplained syncope, but in none of the control subjects. The sensitivity, specificity and diagnostic value of the tilt test were 66.7%, 100.0% and 74.5%, respectively. The average time to the onset of symptoms was 22 ± 12 minutes during the tilt test. Three patterns of response to head-up tilt test were observed in positive responders: vasodepressor pattern with an abrupt fall in blood pressure in 15/28; cardioinhibitory pattern with profound bradycardia in 3/28, and mixed pattern with reduction in both blood pressure and heart rate in 10/28.

Conclusion: The result of this study suggests that the head-up tilt test is a useful and an objectively diagnostic tool for evaluating unexplained syncope in children.

Key words: head-up tilt test, syncope, children

Address for Correspondence:
Prof. D. Junbao
Department of Pediatrics
First Hospital of Beijing Medical University
Si-An Men Street, No. 1
Beijing 100034
P. R. China

Reference:
(CVE. 1999; 4 (1): 8-10)

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