lacc Vol. 4, No.2 August 198'<351-5 351 Two-Dimensional Echocardiographic Diagnosis of Anomalous Origin of the Right Pulmonary Artery From the Aorta: Differentiation From Aortopulmonary Window DOUGLAS H. KING, MD, JAMES C. HUHTA, MD, HOWARD P. GUTGESELL, MD, FACC, DAVID A. OTT, MD* Houston. Texas Utilizing two-dimensional echocardiography, the diagnosis of anomalous origin of the right pulmonary artery from the aorta was made prospectively in a neonate who presented with signs of congestive heart failure. A com- plete echocardiographic evaluation, including both right parasternal short- axis and suprasternal long-axis scans, permitted differentiation from other defects in aortopulmonary septation. Recent advances in the quality of images obtained by twodimensional echocardiography have made the definitive diagnosis of many congenital heart lesions possible. We recently performed echocardiography on an infant with anomalous origin of the right pulmonary artery from the aorta and patent ductus arteriosus. Using previous experiencewith other abnormalities of aortopulmonary septation, we were able to make the correct diagnosis prospectively. These findings were subsequently confirmed by cardiac catheterization. angiography and surgery. Case Report A three week old Caucasian male infant was referred for evaluation of a heart murmur and rapid breathing. Physical examination revealed a well developed, well nourished infant in respiratory distress. The heart rate was 150 b ats/min, the respiratory rate 80/min and the blood pressure 80/50 mm Hg. The apical impulse was at the sixth intercostal space in the anterior axillary line. There was a prominent left parasternal impulse. The first heart sound was normal and the second heart sound was split with accentuation of From the Lillie Frank Abercrombie Section of Cardiology, Department of Pediatrics, Baylor College of Medicine and Texas Children's Hospital, and Division of Surgery, Texas Heart Institute* and St. Luke's Episcopal Hospital. Houston, Texas. Dr. Huhta was supported in part by New Investigator Research Award HL31153 and by Grants HL07190 and RR 05425 from the National Institutes of Health, U.S. Public Health Service, Bethesda, Maryland, and Grant RR-OOI88 from the General Clinical Research Branch, National Institutes of Health, Bethesda, Maryland. Manuscript received December 27, 1983; revised manuscript received February 13, 1984, accepted March 2, 1984. Address for reprints: James C. Huhta, MD, Texas Children's Hospital, 6621 Fannin Street, Houston, Texas 77030. 1984 hy the American College of Cardiology the pulmonary component. There was a grade 3/6 medium frequency systolic ejection murmur at the left midsternal border. The murmur radiated to the right lung field and infraclaviculararea. The pulses were equal in all four limbs. The electrocardiogram revealed left ventricular hypertrophy with strain. Chest radiography revealed cardiomegaly with increased pulmonary vascularity, which was more prominent over the right lung field than the left. Echocardiography (Fig. 1). Two-dimensional echocardiography was performed using an Advanced Technology Laboratories 5.0 MHz mechanical sector transducer. The parasternal long-axis view of the heart revealed an enlarged left atrium and left ventricle and a normal mitral valve. An anomalous vessel exited posteriorly from the ascending aorta. The transducer was then rotated clockwise 90, and with anterior angulation the aortic and pulmonary valves were normal. In the left parasternal short-axis view, the normal bifurcation of the main pulmonary artery could not be seen. There was continuity between the main pulmonary artery and the left pulmonary artery. A high parasternal short-axis view showed the origin of the right pulmonary artery to be in the posterior aspect of the ascending aorta. A suprasternal scan of the ascending aorta revealed a normal left aortic arch with a patent ductus arteriosus extending between the main pulmonary artery and the descending aorta. Subcostal scans showed normal intracardiac anatomy. Cardiac catheterization. Systemic pressure was noted in the main and left pulmonary arteries. The right pulmonary artery could not be entered from the main pulmonary artery. The catheter was advanced prograde from the main pulmonary artery into the descending aorta through a patent 0735-1097/84/$3.00
352 ECHOCARDIOGRAPHY IN ANOMALOUS PULMONARY ARTERY Figure 1. Composite of two-dimensional echocardiographic scans of our patient with anomalous origin of the right pulmonary artery from the aorta. A, High short-axi s parasternal scan of the right pulmonary artery (RPA) arising from the left posterior aspect of the ascendin g aorta (Ao) and the normal continuity between the main (MPA) and left (LPA) pulmonary arteries. B, Parasternal long-axis scan of the ascending aorta (Ao) (white arrow) and the abnorm al origin of the right pulmonary artery (RPA) from it. This appearance may also occur in truncus arteriosus. C, Parasternal short-axis scan demonstrating two semilunar valves (arrows), thereby exclud ing truncu s arteriosu s. D, High parasternal short-axis scan demon strating normal integrity of the wall between the aorta (Ao) and the main pulmonary artery (MPA). A = anterior; AY = aortic valve ; I = inferior ; L = left; LA = left atrium; P = posterior; PYal = pulmonary valve ; R = right; S = superior. ductus arteriosus. A main pulmon ary artery angiogram revealed a normal left pulmonary artery, The right pulmonary artery was not visualized on this injection (Fig. 2, top). A left ventricular angiogram revealed the anomalous origin of the right pulmonary artery from the left posterior aspect of the descending aorta (Fig. 2, bottom). lacc Vol. 4, No.2 August 1984:351-5 Surgery. Surgical repair was performed utilizing cardiopulmonary bypass and hypothermic circulatory arrest. The right pulmonary artery was detached from the aorta and the defect was closed primarily. The right pulmonary artery was then anastomosed to the main pulmon ary artery in an end to side fashion, and the patent ductus arteriosu s was ligated. The postoperative course was uncomplicated and the patient was discharged in good condition 2 weeks later. Discussion Anomalous origin of the pulmonary artery from the aorta is a rare congenital heart lesion. There are approximately 60 cases reported (1-4). In the majority of cases, the right pulmonary artery is anomalous. The most frequently associated defect is a patent ductus arteriosus, present in 38 of 50 patients in one series (5). Patient s with this defect usually present with signs of conge stive heart failure at 3 to 4 weeks of age when the normal postnatal decrease in pulmonary vascular resistance occurs and flow to the anomalous pulmonary artery increases (5).
lacc Vol. ~. No.2 August 198 U51-5 Richardson et al. (6) recently defined anomalous origin of the pulmonary artery from the aorta as part of a spectrum of anomalies resulting from abnormal aortopulmonary septation Failure of septation to occur results in truncus arteriosus. If the right conotruncal ridge arises more posteriorly than normal, unequal partitioningof the aortopulmonary trunk may occur. Depending on the degree of abnormal posterior deviation of the right conotruncal ridge, contact with the sixth aortic arch will result in an aortopulmonary window or anomalous origin of the pulmonary artery from the aorta. ECHOCARDlOGRAPHY IN ANOMALOUS PULMONARY ARTERY 353 Figure 2. Top, Main pulmonary artery angiogram in anteroposterior (left) and lateral (right) views. Note absence of the right pulmonary artery. Right to left shunting through the patent ductus arteriosus is seen (arrow). Bottom, Left ventricular angiogram in the anteroposterior (left) and lateral (right) views. Note the origin of the right pulmonary artery from the left posterior and lateral aspect of the aorta (white arrows). Differential diagnosis. The two-dimensional echocardiographic diagnosis of anomalous origin of the pulmonary artery from the aorta requires an integrated approach using
354 ECHOCARDlOGRAPHY IN ANOMALOUS PULMONARY ARTERY lacc Vol. 4, No.2 August 1984:351~5 Figure 3. Composite of echocardiographic views in an infant with aortopulmonary window and interrupted aortic arch, A, High parasternal shortaxis scan reveals a communication between the aorta (Ao) and main pulmonary artery (MPA). B, Suprasternal long-axis scan reveals communication between the posterior aspect of the ascending aorta (AAo) and the anterior main pulmonary artery (MPA). The left pulmonary artery (LPA) and right pulmonary artery (RPA) can be seen to originate from the main pulmonary artery. C, Suprasternal scan of the aorta (Ao) reveals the origin of the left carotid artery (LCA) and left subclavian artery (LSA) (type A interrupted aortic arch). A anterior; I = inferior; L = left; LA = left atrium; P = posterior; R = right; S = superior.
lacc Vol. 4, No.2 August 1984:351-5 ECHOCARDIOGRAPHY IN ANOMALOUS PULMONARY ARTERY 355 high parasternal long- and short-axis and suprasternal scans. The differentiation of aortopulmonary window from anomalous origin of the pulmonary artery from the aorta is possible by demonstrating continuity between the aorta and the right pulmonary artery and between the main pulmonary and the left pulmonary artery (Fig. la). The suprasternal scan of aortopulmonary window (Fig, 3) may appear similar to that seen with truncus arteriosus (7); however, the presence of two semilunar valves effectively excludes the latter diagnosis (8) (Fig. IC). Scans of the left and right pulmonary arteries and their confluence are also necessary. (Compare Fig. IA and 3B). Because other anomalies of the aorta, such as interrupted aortic arch (Fig. 3C), may coexist with any of the diagnoses cited, a complete examination of the aorta including the aortic isthmus and aortic arch branching should always be performed (9). References 1. Frary G, Albers W, Shah J. Echocardiographic findings of isolated anomalous origin of the right pulmonary artery from the ascending aorta J Cardiovasc Ultrasonography 1983;2:285-8. 2. Duncan W, Freedom R, Olley P, Rowe R. Two-dimensional echocardiographic identification of hemitruncus: anomalous origin of one pulmonary artery from the ascending aorta with the other pulmonary artery arising normally from the right ventricle. Am Heart J 1981;102:892-6. 3. Armer R, Shumacker H, Klatte E. Origin of the right pulmonary artery from the ascending aorta. Report of a surgically corrected case. Circulation 1961;24:662-8. 4. Redo SF, Foster H, Engle MA, Ehler KH. Anomalous origin of the right pulmonary artery from the ascending aorta. J Thorac Cardiovasc Surg 1965;50:726-33. 5. Keane J, Maltz D, Bernhard W, et al. Anomalous origin of one pulmonary artery from the ascending aorta. Diagnostic. physiological, and surgical considerations. Circulation 1974;50:588-94. 6. Richardson J, Doty D, Rossi N, Ehrenhaft J. The spectrum of anomalies of aortopulmonary septation. J Thorac Cardiovasc Surg 1979;78:21-7. 7. Rice MJ, Seward JB, Hagler OJ, Mair DD, Tajik AJ. Visualization of aortopulrnonary window by two-dimensional echocardiography. Mayo Clin Proc 1982;57:482-7. 8. Smallhom J, Anderson R, Macartney F. Two-dimensional echocardiographic assessment of communications between ascending aorta and pulmonary trunk or individual pulmonary arteries. Br Heart J 1982;47:563-72. 9. Huhta JC, Gutgesell HP, Latson LA, Mullins CEo Two-dimensional echocardiographic assessment of the aorta in infants and children with congenital heart disease (abstr). J Am Coli Cardiol 1983;1:681.