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[In Process Citation]
Kaku1
1Servico de Cardiologia Pediatrica do Hospital de Santa Marta.
Insights
This study investigated coronary circulation in Transposition of the Major Arteries (TMA), finding larger coronary orifices and altered origins. Post-Jatene surgery, coronary arteries remained patent with preserved function, though ongoing follow-up is recommended.
Area of Science:
- Cardiology
- Pediatric Cardiology
- Cardiac Surgery
Background:
- Transposition of the Major Arteries (TMA) involves parallel systemic and pulmonary circulation, requiring communication for survival.
- Jatene's operation is the preferred treatment for TMA, but long-term success hinges on coronary artery patency and left ventricular function.
- Uncertainty regarding coronary artery growth and potential silent lesions necessitates detailed study of coronary circulation in TMA.
Purpose of the Study:
- To analyze coronary artery anatomy and circulation in Transposition of the Major Arteries (TMA).
- To evaluate coronary artery patency, myocardial function, and ischemia markers post-Jatene operation for TMA.
- To establish optimal angiographic views for diagnosing coronary anatomy in TMA.
Main Methods:
- Anatomic analysis of 130 heart specimens and a prospective angiographic study in 50 children with TMA.
- Assessment of myocardial ischemia using Troponin-T (cTnT) in 54 children and myocardial function evaluation in 30 post-Jatene patients.
- Myocardial perfusion scintigraphy, dobutamine stress echocardiography, and angiocardiography were used to assess coronary artery permeability and function.
Main Results:
- TMA hearts frequently showed a right-anterior aorta (65%) and larger pulmonary than aortic orifices.
- Coronary orifices were larger in TMA compared to normal hearts, with variations in coronary artery origins.
- Postoperative angiograms revealed patent coronary arteries with no stenosis, and preserved myocardial perfusion for nearly three years; cTnT accurately assessed myocardial lesions.
Conclusions:
- The study provides detailed morphologic and functional insights into coronary circulation in TMA and post-Jatene repair.
- While coronary arteries remained patent and function preserved post-surgery, ongoing monitoring is advised due to rare ischemic changes.
- Accurate pre-operative diagnosis of coronary anatomy using specific angiographic views is crucial for surgical planning.
Abstract:
INTRODUCTION AND AIMS: Transposition of the Major Arteries (TMA) is defined as atrioventricular concordance with ventriculoarterial discordance. Systemic and pulmonary circulation are in parallel and a communication between the two is essential for survival. Progress in echocardiography, cardiac catheterization, treatment with prostaglandin and cardiac surgery have reduced mortality and contributed to the adoption of Jatene's operation as the treatment of choice for TMA. Long term success depends on the continued patency of the coronary arteries and on the preservation of left ventricular function. Reports of significant silent coronary lesions and the uncertainty of long-term growth of the arterial anastomosis lead us to study coronary circulation in TMA. METHODS: Anatomic analysis of 130 heart specimens was followed by a prospective angiographic study in 50 children with TMA to select appropriate views for the diagnosis of the coronary anatomy. Troponin-T was tested as marker of myocardial ischaemia in 54 children and myocardial function was evaluated in 30 children after Jatene's operation with myocardial perfusion scintigraphy, dobutamine-induced stress echocardiography and angiocardiography. Permeability of the coronary arteries was assessed with angiocardiography. RESULTS: The morphologic study led us to conclude that the right-anterior aorta was present in 65% of hearts with TMA, followed by side-by-side great arteries; the pulmonary orifice was of the same size or larger than the aortic orifice in the majority of TMA. Major non-alignment of the aortic and pulmonary comissures was recorded in 14 to 30% of TMA specimens. The diameter of the coronary orifices was larger in TMA when compared to a normal heart. In cases with right anterior aorta, normal coronary pattern was the most frequent, followed by the pattern where the circumflex coronary artery (Cx) emerged from the right coronary (RCA). In cases with side-by-side great arteries, both patterns were equally frequent. In TMA with normal coronary pattern, the angles between the right and left coronary arteries and the aorta at the origin were equal and similar to the RCA angle with the aorta in a normal heart (about 90 degrees). The RCA in TMA was longer than in a normal heart. Although we could not find any publication reporting the angles and lengths of the coronary arteries, these measurements must be considered whenever translocation of the coronary arteries is attempted. A laid-back aortogram led us to the correct diagnosis of the coronary anatomy prior to surgery. Our study confirmed that MBCK had very low specificity for myocardial ischaemia but cTnT values correctly evaluated the extent of the myocardial lesion. Postoperative angiograms showed patent coronary arteries with no stenosis in all cases and myocardial perfusion was well preserved almost three years after surgery. The detection of ischaemic changes in three cases, in perfusion scan with normal function on stress-echo and on left ventriculogram, led us to warrant on-going follow-up.