[The tilt-table test in assessing syncope of unknown origin: do differences exist between children and adults?]

Area of Science:

• Pediatric Cardiology
• Autonomic Nervous System Function
• Diagnostic Testing

Background:

• Unexplained syncope is a common clinical problem in both children and adults.
• The head-up tilt test (HUTT) is a valuable diagnostic tool for evaluating syncope.
• Limited data exists on age-specific differences in HUTT outcomes.

Purpose of the Study:

• To compare clinical profiles, diagnostic performance, and response patterns of HUTT between children and adults with unexplained syncope.
• To identify age-related variations in the diagnostic utility of HUTT.
• To characterize the types of positive responses observed in pediatric versus adult syncope evaluations.

Main Methods:

• A comparative study involving 31 children and 123 adults diagnosed with unexplained syncope.
• Standardized head-up tilt testing protocol at 70 degrees for 30 minutes.
• Low-dose isoprenaline infusion was administered if the baseline test was negative.

Main Results:

• No significant differences were observed in the overall clinical profile or diagnostic performance of HUTT between children and adults.
• Adults experienced severe traumatism more frequently than children (25% vs. 3%, p < 0.05).
• Children predominantly showed positive responses during basal tilting (92% vs. 50%, p < 0.05), with a significantly higher rate of cardio-inhibitory responses (42% vs. 8%, p < 0.01) compared to adults.

Conclusions:

• Children with syncope rarely require isoprenaline for a positive head-up tilt test compared to adults.
• Pediatric patients demonstrate a substantially higher incidence of cardio-inhibitory responses during HUTT.
• These findings highlight distinct autonomic responses to HUTT in pediatric versus adult populations.