Asian Cardiovasc Thorac Ann 2007;15:e23-e24
© 2007 Asia Publishing EXchange Ltd
Pulmonary Hypertension Alters Natural History of Anomalous Left Coronary Artery
Jayesh Akbari, MS,
Sanjay Theodore, MS,
Soman R Krishnamanohar, MCh,
Kurur S Neelakandhan, MCh
Division of Cardiovascular & Thoracic Surgery, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Trivandrum, India
For reprint information contact: Soman R Krishnamanohar, MCh Tel: 91 471 244 4496 Fax: 91 471 244 6933 Email: sanjay{at}sctimst.ac.in, Division of Cardiovascular & Thoracic Surgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala 695 011, India.
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ABSTRACT
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A girl who was diagnosed at 8 months old with anomalous left coronary artery from the pulmonary artery and was subsequently lost to follow-up, presented at the age of 11 years with congestive heart failure and severe mitral regurgitation with supra-systemic pulmonary artery pressure. With progressive mitral regurgitation, coronary steal is reduced by the rising pulmonary artery pressure, and patients present late with severe valvular cardiomyopathy.
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INTRODUCTION
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Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a rare but life-threatening congenital heart defect that usually presents in infancy with congestive heart failure (CHF) and ischemic cardiomyopathy.1 Untreated, 90% of patients die within the first year of life. Extensive collateralization, dominant right coronary circulation, or ostial stenosis of the left main coronary artery arising from the pulmonary artery (PA) facilitate survival to adulthood. We present a case of ALCAPA where severe PA hypertension secondary to ischemic mitral regurgitation (MR) prolonged the natural history of ALCAPA.
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CASE REPORT
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An 11-year-old girl was admitted with pulmonary edema and CHF. She was intubated and ventilated. She had been previously admitted at the age of 8 months with a severe respiratory infection and CHF. Anomalous left coronary artery from the pulmonary artery was diagnosed at that time, but her parents refused surgery and she was lost to follow-up. On examination, she was in atrial fibrillation, jugular venous pressure was raised (11 cm H2O), and there was a grade 4/6 pansystolic murmur at the apex. Chest radiography (Figure 1
) showed a cardiothoracic ratio of 90% and massive left atrial (LA) enlargement. Electrocardiography showed atrial fibrillation, left ventricular (LV) volume overload and hypertrophy with strain pattern; there was no evidence of an old myocardial infarction. Transthoracic echocardiography showed an LV dimension of 55/22 mm, a right ventricular dimension of 26 mm, and LA dimension of 70 mm, with grade IV MR. The right coronary artery was ectatic and the left coronary artery (LCA) was seen arising from the PA. No regional wall motion abnormality was seen. Cardiac catheterization showed antegrade flow into the LCA from the PA (Figure 2). The PA pressure was supra-systemic (120 mm Hg).
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Figure 2. Preoperative angiography; (A) Right coronary injection showing a relatively diminutive right coronary artery with poor collateralization and no flow into the left system and pulmonary artery; (B) Pulmonary artery injection showing antegrade flow into the left anterior descending and left circumflex arteries.
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The patient underwent emergency surgery. Under cardiopulmonary bypass, the main PA was dissected, and antegrade cold blood cardioplegia was delivered to the aortic root and PA simultaneously after both vessels were cross clamped. The left atrium was opened parallel to the Waterston groove. There was massive dilatation of the mitral annulus with severely deformed leaflets. The valve was replaced with preservation of the subvalvular apparatus. The LA appendage was excluded and para-annular LA plication was performed. Anatomical correction of the ALCAPA was carried out by translocating it to the aorta. The patient was weaned off bypass and following delayed sternal closure, she was extubated after 5 days. At the one-year follow-up, she was in New York Heart Association functional class I. Follow-up transthoracic echocardiography showed an LV dimension of 37/19, and RV systolic pressure of 40 mm Hg, with a widely patent LCA origin.
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DISCUSSION
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Anomalous left coronary artery from the pulmonary artery is a rare congenital heart defect that commonly presents in infancy with CHF secondary to myocardial ischemia. The myocardial ischemia is related to the direction of blood flow in the LCA. At birth, neonates are asymptomatic because high pulmonary vascular resistance and PA pressure prevents coronary steal into the PA. Subsequent to the fall in PA pressure in early infancy, pressure in the LCA drops and myocardial perfusion depends entirely on the right coronary artery and the intercoronary cross circulation.1 However, these collaterals can bypass the capillary bed, deprive the myocardium of oxygen, and promote ischemia. These effects are aggravated in the presence of LV hypertrophy and dilatation, accentuating endocardial ischemia. Significant coronary steal results in severe ischemia in the LCA territory, leading to myocardial infarction and subsequent Left ventricular dysfunction, MR, and CHF.2 Mitral regurgitation is thought to result from LV dilatation, papillary muscle ischemia or infarction. Left ventricular dysfunction leads to mitral annular enlargement, while papillary muscle ischemia can lead to chordal elongation or rupture.3 Severe MR results in elevated LA pressure and pulmonary venous hypertension with subsequent PA hypertension. Ideally, valve repair should be performed, this will preserve LV function by preventing alteration in LV geometry; moreover, anticoagulation-related complications can be avoided. In our patient, the valve was thickened, fibrotic, and fused, and it was considered unsuitable for repair.
Our patient initially presented with CHF during the first year of life, which coincides with the fall in neonatal pulmonary vascular resistance and initiation of coronary steal. We believe that development of collaterals, along with a dominant right coronary artery, and gradual progression of MR which caused a rise in PA pressure, precluded significant coronary steal and ameliorated her symptoms. It has been previously recognized that left-to-right shunts that increase the PA pressure prevent coronary steal and secondary myocardial ischemia, and interruption of left-to-right shunts can unmask the presence of ALCAPA.2 Progression of MR and the rise in PA pressure did not remain benign and gradually resulted in cardiomegaly, decompensated valvular cardiomyopathy, and finally CHF. Whether antegrade flow in the LCA with desaturated blood due to supra-systemic PA pressure contributed to the sudden deterioration of the clinical condition remains conjecture. The PA pressure secondary to mitral valve disease usually regresses over time. Our patient had a stormy postoperative period with delayed sternal closure, high inotropic support, and prolonged ventilation. At the last follow-up, her RV systolic pressure was less than half the systemic value, and she was in functional class I.
We believe that progression of MR and resultant PA hypertension in patients with ALCAPA may ameliorate symptoms of ischemic cardiomyopathy by preventing coronary steal. This may be one of the many reasons why certain patients remain asymptomatic until adulthood.
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REFERENCES
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- Vouhe PR, Baillot-Vernant F, Trinquet F, Sidi D, de Geeter B, Khoury W, et al. Anomalous left coronary artery from the pulmonary artery in infants. Which operation? When? J Thorac Cardiovasc Surg 1987;94:192–9.[Abstract]
- Ortiz E, de Leval M, Somerville J. Ductus arteriosus associated with an anomalous left coronary artery arising from the pulmonary artery: catastrophe after duct ligation. Br Heart J 1986;55:415–7.[Abstract/Free Full Text]
- Huddleston CB, Balzer DT, Mendeloff EN. Repair of anomalous left main coronary artery arising from the pulmonary artery in infants: long-term impact on the mitral valve. Ann Thorac Surg 2001;71:1985–9[Abstract/Free Full Text]
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ABSTRACT
INTRODUCTION
