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Possibility of postnatal left ventricular growth in selected infants with non-apex-forming left ventricles
L L Minich1, L Y Tani, J A Hawkins
1Department of Pediatrics, Primary Children's Medical Center, and the University of Utah, Salt Lake City 84113, USA.
Insights
Infants with a non-apex-forming left ventricle showed significant growth in key cardiac measurements within the first month of life. This suggests potential for postnatal left ventricular development despite congenital abnormalities.
Area of Science:
- Pediatric Cardiology
- Congenital Heart Disease
- Cardiac Development
Background:
- Left ventricular (LV) development is crucial for biventricular function.
- Congenital heart defects can significantly impact LV morphology and growth.
- Understanding postnatal LV growth potential is vital for managing complex cardiac anomalies.
Purpose of the Study:
- To evaluate the postnatal growth potential of the left ventricle in infants with a non-apex-forming morphology.
- To assess changes in cardiac dimensions and function during the early postnatal period.
Main Methods:
- Retrospective review of echocardiograms from seven infants with non-apex-forming left ventricles.
- Comparison of cardiac measurements between initial assessment (7 days) and 1-month follow-up (36 days).
- Analysis included aortic dimensions, LV volumes and mass indexed to body surface area (BSA), and valve areas.
Main Results:
- Despite stable weight and BSA, significant increases (p < 0.05) were observed in aortic annulus diameter, aortic root diameter (indexed to BSA), LV long axis to heart long axis ratio, LV end-diastolic volume (indexed to BSA), LV mass (indexed to BSA), mitral valve area (indexed to BSA), LV area, and Rhodes score.
- Tricuspid valve area (indexed to BSA) and heart long axis (indexed to BSA) remained unchanged.
- Five infants demonstrated adequate growth for biventricular physiology, with four surviving into childhood.
Conclusions:
- A non-apex-forming left ventricle demonstrates significant postnatal growth potential in the first month of life.
- This growth appears sufficient for supporting biventricular physiology in a subset of affected infants.
- Further research is warranted to explore long-term outcomes and management strategies.
Abstract:
To evaluate postnatal left ventricular growth potential, we reviewed the echocardiograms of seven infants with left ventricles that did not form an apex. Prostaglandins were used to maintain patency of the ductus arteriosus in six infants. Associated abnormalities included aortic stenosis in five, coarctation in three, and left atrial isomerism in one. Initial echocardiographic measurements (7 +/- 9 days) were compared with measurements at 1 month (36 +/- 9 days). Weight (3.0 +/- 0.1 vs 3.0 +/- 0.5 kg) and body surface area (BSA) (0.2 +/- 0.01 vs 0.2 +/- 0.01 m2) did not change. Comparing initial measurements with measurements at 1 month, there were significant increases (p < 0.05) in aortic annulus diameter (4.5 +/- 0.5 vs 5.6 +/- 0.7 mm), aortic root diameter indexed to BSA (2.9 +/- 0.5 vs 3.7 +/- 0.7 cm/m2), ratio of the long axis of the left ventricle to the long axis of the heart (0.74 +/- 0.1 vs 0.86 +/- 0.1), left ventricular end-diastolic volume indexed to BSA (10 +/- 2 vs 24 +/- 9 ml/m2), left ventricular mass indexed to BSA (27 +/- 13 vs 47 +/- 28 gm/m2), mitral valve area indexed to BSA (2.3 +/- 0.5 vs 3.2 +/- 0.7 cm2/m2), left ventricular area (2.1 +/- 0.5 vs 3.6 +/- 1.1 cm2), and Rhodes score (-2.7 +/- 0.5 vs -1.1 +/- 0.9). Tricuspid valve area indexed to BSA (5.8 +/- 1.5 vs 6.1 +/- 1.1 cm2/m2) and long axis of the heart indexed to BSA (13.0 +/- 2.8 vs 13.6 +/- 2.9 cm/m2) did not change. The increase in measurements appeared adequate for biventricular physiology in five infants (four are alive [3.9 +/- 2.6 years] and one died after not being able to wean from the ventilator). These data suggest that a non-apex-forming left ventricle may have postnatal growth potential.