Intracardiac electrography in children and young adults

Area of Science:

• Pediatric Cardiology
• Electrophysiology
• Cardiac Conduction System

Background:

• Interpretation of intracardiac electrography (IE) in children is challenging due to a lack of established normal values.
• Variability in conduction intervals necessitates clear reference ranges for accurate diagnosis in pediatric patients.

Purpose of the Study:

• To define normal conduction intervals using IE in a pediatric population.
• To investigate conduction intervals in various cardiac disease states in children and young adults.
• To assess the safety and utility of IE with His bundle potential (HBP) recording in pediatric electrophysiologic studies.

Main Methods:

• Intracardiac electrography (IE) was performed on 158 children and young adults (3 days to 33 years).
• His bundle potential (HBP) was recorded in 156 subjects.
• Conduction intervals were analyzed in subjects with normal conduction, first-degree AV block, congenital complete AV block, and right bundle branch block.

Main Results:

• No statistically significant age-related differences were found in internodal, A-V nodal, or His-Purkinje conduction intervals in subjects with normal conduction.
• Therapeutic digitalis levels did not affect conduction intervals.
• The site of block in AV block could not be predicted by surface ECG, but IE provided this information. No conduction abnormalities were found in subjects with right bundle branch block.

Conclusions:

• Intracardiac electrography (IE) provides a safe and informative method for pediatric electrophysiologic investigations.
• Established normal values for conduction intervals in children and young adults can be determined using IE.
• IE is crucial for accurately localizing block in AV block and assessing conduction in pediatric cardiac conditions.