Different haemodynamic patterns in head-up tilt test on 400 paediatric cases with unexplained syncope

Area of Science:

• Pediatric Cardiology
• Autonomic Nervous System Function
• Diagnostic Testing

Background:

• Unexplained syncope is a common reason for pediatric referrals.
• Head-up tilt testing (HUTT) is a key diagnostic tool for evaluating syncope.
• Understanding hemodynamic patterns in pediatric syncope is crucial for effective management.

Purpose of the Study:

• To characterize the diverse hemodynamic response patterns observed during head-up tilt testing in a large cohort of children with unexplained syncope.
• To identify the prevalence of different syncope subtypes based on HUTT findings.

Main Methods:

• Retrospective analysis of 400 pediatric patients (aged 5-18 years) diagnosed with unexplained syncope.
• Standardized head-up tilt testing protocol involving 25 minutes supine rest and 20 minutes of 70° upright tilt.
• Classification of patients into nine distinct hemodynamic pattern groups based on their response to tilt testing.

Main Results:

• The majority of patients (69.2%) had negative HUTT results.
• Specific diagnoses included vasovagal syncope (9.5%), orthostatic intolerance (7.0%), and postural orthostatic tachycardia syndrome (POTS) (6.0%).
• Various subtypes of vasovagal syncope and POTS were identified, indicating heterogeneous responses.

Conclusions:

• Head-up tilt testing reveals at least nine distinct hemodynamic patterns in children with unexplained syncope.
• Orthostatic intolerance syndromes are significant contributors to pediatric syncope, impacting daily activities.
• Further clinical investigation is warranted to improve the diagnosis and management of these conditions in pediatric populations.