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Ventricular development and function in complete transposition: angiocardiographic evaluation
Insights
In complete transposition of the great arteries, the left ventricle shows inadequate mass and decreased contractility in the first year of life, despite normal initial development. The right ventricle volume increases, but ejection fraction declines.
Area of Science:
- Pediatric Cardiology
- Congenital Heart Disease
- Cardiac Development
Background:
- Complete transposition of the great arteries (TGA) presents unique challenges in ventricular development and function.
- Early assessment of ventricular adaptation is crucial for managing TGA patients.
Purpose of the Study:
- To evaluate the developmental trajectory and functional status of both ventricles in infants with TGA.
- To analyze how associated cardiac lesions and age influence ventricular performance.
Main Methods:
- Retrospective analysis of 50 left and 41 right ventricular cineangiograms from 40 infants with TGA (situs solitus).
- Patients categorized by ventricular septal integrity, presence of pulmonary stenosis, and age (<60 days vs. >60 days).
- Assessment of ventricular volumes, ejection fraction, systolic pressure, end-systolic volume, left ventricular mass, and stress.
Main Results:
- Left ventricle (LV) volume overload is evident from birth; LV mass fails to keep pace with volume increase, becoming inadequate by one year.
- In TGA with an intact ventricular septum, LV contractility decreases during the first year, despite adequate oxygen saturation.
- Right ventricle (RV) volume increases post-atrial septostomy, but ejection fraction progressively declines, linked to reduced contractility.
Conclusions:
- Infants with TGA experience progressive LV inadequacy and functional decline within the first year of life, even with an intact septum.
- Associated anomalies and hemodynamic pressures significantly impact LV mass and function.
- RV function deteriorates over time, necessitating careful monitoring and management strategies.
Abstract:
We studied 50 left ventricular cineangiograms and 41 right ventricular cineangiograms of 40 patients with usual atrial arrangement (situs solitus) together with concordant atrioventricular and discordant ventriculo-arterial connexions (complete transposition), catheterized between 1 day and 12 months of age. Our purpose was to evaluate ventricular development and function. The patients were subdivided on the basis of associated lesions into groups with intact ventricular septum; with ventricular septal defect; with ventricular septal defect together with pulmonary stenosis and with pulmonary stenosis in isolation. Each group was further separated according to age into those patients below and above 60 days. Ventricular volumes, ejection fraction and the ratio between systolic pressure and end-systolic volume were evaluated for both ventricles. The left ventricular mass, stress, and the ratio of stress to end-systolic volume were also calculated. A volume overload leads to increased left ventricular volume even at birth. With an intact ventricular septum, the left ventricle in patients with complete transposition is normal at birth and also during the first weeks of life. Myocardial mass, however, does not increase proportionately with increase in volume as the patient grows and it remains inadequate by the age of one year. The left ventricular mass is also inadequate in patients with associated anomalies when the left ventricular pressure is less than 60 mm Hg. Moreover, the left ventricle in presence of an intact ventricular septum presents a decrease in contractility during the first year of life despite the finding of a satisfactory arterial oxygen saturation. The right ventricle has a normal volume at birth which increases during the first year due to a greater diastolic filling following atrial septostomy. We noted a progressive decrease in ejection fraction, however, which is related to various factors including a reduction in contractility.