Related Experiment Videos
Wall thickness of ventricular chambers in transposition of the great arteries: surgical implications
Insights
This study on transposition of the great arteries (TGA) found that left ventricular wall thickness decreases significantly with age in TGA patients. These findings suggest limitations for anatomic correction surgery in older infants.
Area of Science:
- Cardiovascular Pathology
- Pediatric Cardiology
- Congenital Heart Disease
Background:
- Transposition of the great arteries (TGA) is a critical congenital heart defect.
- Understanding ventricular remodeling in TGA is crucial for surgical outcomes.
Purpose of the Study:
- To analyze ventricular wall thickness and ratios in TGA specimens.
- To determine age-related changes in ventricular morphology in TGA.
- To inform surgical timing for TGA correction.
Main Methods:
- Histological analysis of 104 TGA hearts and 63 normal controls.
- Measurement of left (LV-T) and right (RV-T) ventricular free wall thickness.
- Calculation of left/right ventricular (LV/RV) thickness ratio across age groups.
Main Results:
- Left ventricular thickness fell below normal limits by 8 months (TGA+IVS) and 18 months (TGA+VSD).
- Right ventricular thickness exceeded normal limits from the first month in all TGA groups.
- LV/RV ratio was consistently below 1, decreasing significantly after the neonatal period in TGA+IVS.
Conclusions:
- Progressive left ventricular underdevelopment occurs in TGA, particularly after the neonatal period.
- Age limits for anatomic correction should be considered based on ventricular morphology.
- Findings suggest caution against anatomic correction in TGA patients older than 8-18 months, depending on VSD status.
Abstract:
One hundred four specimens of complete transposition of the great arteries (TGA) were studied. The free wall thickness of the left (LV-T) and right (RV-T) ventricular chambers and the left ventricular/right ventricular (LV/RV) thickness ratio for all hearts were analyzed. A control group of 63 normal hearts was also studied. Specimens of TGA were divided into four groups: (1) TGA with intact ventricular septum (TGA + IVS); (2) TGA with ventricular septal defect (TGA + VSD); (3) TGA with a large patent ductus arteriosus (TGA + PDA); (4) TGA with pulmonary stenosis (TGA + PS). In Group I, LV-T was under the 95% confidence limits for normality after 8 months of age, and in Group II, the same was true after 18 months of age. For all groups the RV-T was above the 95% confidence limits for normality from the first month of age. The LV/RV ratio was under 1 in every group. Group I showed a significant decrease in the LV/RV ratio after the neonatal period (p less than 0.005). The potential failure of the left ventricle after anatomic correction of TGA is explained by a multifactorial hypothesis. In view of the ventricular wall thickness findings, we do not recommend the anatomic correction after 8 months of age in Group I or after 18 months in Group II.