Coronary normograms and the coronary-aorta index: objective determinants of coronary artery dilatation

Area of Science:

• Pediatric Cardiology
• Diagnostic Imaging
• Biometry

Background:

• Establishing normal reference ranges for coronary artery diameters is crucial for diagnosing pediatric heart conditions.
• Echocardiography is a non-invasive tool for assessing cardiac structures in children.
• Previous studies may lack comprehensive data on coronary artery dimensions in Asian pediatric populations.

Purpose of the Study:

• To prospectively determine the normal proximal left (LCA) and right (RCA) coronary artery diameters in healthy children.
• To develop regression equations and z-score graphs for objective assessment of coronary artery size.
• To evaluate the utility of the coronary-aorta index as a rapid screening tool for coronary dilatation.

Main Methods:

• Prospective echocardiographic measurements of LCA, RCA, and aortic annulus (AoA) internal diameters in 390 healthy Asian children (2 months to 8 years).
• Maximal diastolic diameters of LCA and RCA were measured at standardized sites.
• Correlation analysis (Pearson's R) and regression modeling were used to establish relationships between coronary diameters and anthropometric/anatomic variables.

Main Results:

• LCA and RCA diameters showed strong linear correlations with age, height, weight, body surface area, and AoA (R > 0.8, p < 0.005).
• Regression equations and z-score graphs were successfully constructed for LCA and RCA.
• The coronary-aorta index (LCA/AoA and RCA/AoA) remained consistent across different demographics, suggesting its independence from age, sex, and body size.

Conclusions:

• Reference ranges for proximal coronary artery diameters in normal children have been established.
• The developed regression equations and z-score graphs offer objective methods for identifying coronary size abnormalities.
• The coronary-aorta index provides a simple and effective means for initial detection of coronary dilatation.