Cardiorespiratory exercise tolerance in asymptomatic children with Ebstein's anomaly

Area of Science:

• Pediatric Cardiology
• Cardiopulmonary Exercise Physiology

Background:

• Ebstein's anomaly is a congenital heart defect affecting the tricuspid valve.
• Asymptomatic children with Ebstein's anomaly may have undiagnosed exercise limitations.

Purpose of the Study:

• To assess cardiorespiratory exercise tolerance in asymptomatic children with Ebstein's anomaly.
• To identify factors contributing to reduced exercise capacity in this population.

Main Methods:

• Prospective study involving 11 children (mean age 9.6 years).
• Evaluations included spirometry, cardiopulmonary exercise testing (CPET), and contrast echocardiography.
• Children were categorized based on the presence (group 1) or absence (group 2) of a right-to-left atrial shunt.

Main Results:

• Reduced maximal oxygen uptake (VO2 max) was observed, strongly correlated with oxygen saturation in group 1 (p < 0.0001).
• Oxygen saturation at peak exercise was significantly lower in group 1 (85.7%) compared to group 2 (98.2%) (p = 0.03).
• Oxygen desaturation during exercise was linked to a right-to-left atrial shunt (p = 0.01) and smaller left ventricle size (p = 0.05).

Conclusions:

• Decreased exercise tolerance in asymptomatic Ebstein's anomaly is associated with right-to-left atrial shunts and smaller left ventricles.
• Contrast echocardiography is recommended to detect atrial septal defects in children with Ebstein's anomaly experiencing poor exercise tolerance.