Echocardiographic manifestations of d-transposition of the great vessels

PEDIATRIC CARDIOLOGY

Echocardiographic Manifestations of d-Transposition of the Great Vessels

JAMES C. DILLON, MD HARVEY FEIGENBAUM, MD, FACC LEE L. KONECKE, MD JERGEN KEUTEL, MD ROGER A. HURWlTZ, MD, FACC RICHARD H. DAVIS, MD SONIA CHANG, BA

Indianapolis. Indiana

From the Departments of Medicine and Pediatrics, Indiana University School of Medicine, and the Krannert Institute of Cardiology, Marion County General Hospital, Indianapolis, Ind. This study was supported in part by the Herman C. Krannert Fund, Eli Lilly and Company, U.S. Public Health Service Grants HE0981506, HE-6308, HTS-5363, HE-5749 and the Indiana Heart Association. Manuscript accepted January 19, 1973. Address for reprints: James C. Dillon, MD, Indiana University, University Quarter, 1100 W. Michigan St., Indianapolis, Ind. 46202.

74

July 1973

Echocardiograms were obtained from 16 patients with d-transposition of the great vessels proved at catheterization. These echocardiograms were compared with those obtained from 74 children who had congenital heart disease proved at catheterization but no transposition of the great vessels and those from 60 normal children. All 16 patients with transposition of the great vessels showed superimposition of the great vessels without intervening crista, and in 14 of 16 patients simultaneous recording of echoes from the semilunar valves was observed. This finding was not observed in the 74 children with other forms of congenital heart disease or in the 60 normal children. Superimposition of the great vessels with simultaneous recording of semilunar valve echoes appears to be specific for dtransposition of the great vessels.

Transposition of the great vessels is the most common cyanotic heart disease observed in newborn infantsJ Various studies show it comprises between 3.9 and 5.4 percent of all congenital cardiac lesions, 2-4 ranking behind ventricular septal defect, atrial septal defect, patent ductus arteriosus, coarctation, tetralogy of Fallot, pulmonic stenosis and aortic stenosis. This serious malformation is characterized by the aorta originating anteriorly from the right ventricle and the pulmonary artery originating posteriorly from the left ventricle. Death rapidly occurs when there are no other associated cardiac defects. The average life expectancy at birth has been reported to be 0.65 years, increasing to 3.92 years at age 1 year. 5 Associated lesions have a marked effect on the overall prognosis, which has been greatly improved by the recent introduction of the Rashkind atrial balloon septectomy. 6 Often the complexity of congenital heart disease can only be disclosed by cardiac catheterization and cineangiography, but these procedures are not without risk, especially in the very young cyanotic infant. 7 The use of echocardiography in heart disease in adults is well established, 8 and the scope of this noninvasive technique is constantly being enlarged to include the study of many congenital defects. 9 In our recent recordings in children, we noted certain specific echocardiographic findings in pat!ents with transposition of the great vessels which we describe in this report . M e t h o d s and Materials

Three groups of patients were studied. The first group was composed of 16 patients who had undergone selective right and left heart catheterization and cineangiography and were found to have d-transposition of the great vessels. The second group was composed of 74 children who had undergone cardiac catheterization and were found to have congenital heart lesions other than transposition of the great vessels. The third group was composed of 60 normal children who did not undergo cardiac catheterization.

The American Journal of CARDIOLOGY

Volume 32

ECHOCARDIOGRAM IN d-TRANSPOSITION OF GREAT VESSELS--DILLON ET AL.

The 16 patients with transposition ranged in age from 5 days to 16 years (mean 4.4 years). Six patients were under age 1 year, and 3 patients were less than 1 week old. Sedation was not employed during the echocardiographic evaluation of any patient. All 3 groups were examined by standard echocardiographic techniques. An Ekoline 20 Mark IIA echograph was employed with the use of an Electronics for Medicine recorder on a Honeywell model 1856 line scan recorder. In the younger children, a 3.5 megaHertz nonfocused transducer with an outer diameter of 0.25 inch was used and in the older patients, a 2.25 megaHertz transducer with an outer diameter of 0.5 inch focused at 7.5 cm. A water-soluble gel was utilized to insure airless contact between the patient's skin and the transducer. All patients were examined in the recumbent position with the transducer placed along the third or fourth left intercostal space near the left sternal border so as to record echoes from the mitral valve. Once the mitral valve echoes were recorded, the transducer was directed superiorly toward the right shoulder, and the ultrasonic beam entered the root of the aorta and left atrium as previously described, s,~° The exact angle of the transducer was adjusted to record echoes from a semilunar valve, usually the aortic valve, within the root of the aorta. To record the pulmonic valve echo, usually one had to direct the ultrasonic beam superiorly and to the left of the aortic valve. ~,~ The recording sequence was from the mitral to aortic to pulmonic valve, or the reverse, depending on how easy it was to locate the valves. Results

N o r m a l a o r t i c a n d p u l m o n i c v a l v e r e l a t i o n : Figure 1 is an e c h o c a r d i o g r a m showing the relation between the p u l m o n a r y artery and the aorta and their respective valves in the n o r m a l situation. In this echocardiogram the ultrasonic b e a m was initially directed at the p u l m o n a r y artery at the level of the p u l m o n i c valve. A thick dark b a n d of echoes is seen below and posterior to the p u l m o n a r y artery and is t h o u g h t to originate from the crista. The t r a n s d u c e r was then tilted to the p a t i e n t ' s right a n d inferiorly in order to record from the root of the aorta a n d the left

FIGURE 1. Echocardiogram from a patient with normally positioned great vessels. The ultrasonic beam initially is directed at the pulmonary artery at the level of the pulmonic valve (PV). The transducer is then tilted to the aorta with its aortic valve (AV). The left atrium (LA) lies behind the aorta. By reading the echogram from right to left, one can see that the pulmonary artery dips posteriorly, and at the level of the pulmonic valve the posterior wall of the pulmonary artery is at the mid-portion of the aorta. Behind the pulmonic valve is a thick band of echoes thought to originate from the crista (CR). At no time are echoes from both semilunar valves recorded simultaneously.

atrium. The aortic valve is seen within the aorta. At this level the space anterior to the aorta represents the right ventricular outflow tract, and there is no evidence of the pulmonic valve. By reading the echocardiogram from right to left or from aortic valve to p u l m o n i c valve, one sees t h a t the anterior wall of the aorta; which is also the posterior wall of the right

FIGURE 2. Echocardiogram from a patient with dtransposition of the great vessels; the ultrasonic beam is scanned from the great vessels to the left ventricle. The anterior artery (aorta [AO]) and the posterior artery (pulmonary artery [PAl) run parallel to each other without an intervening crista. In addition, echoes from both semilunar valves (V) are recorded simultaneously. The echoes from the interventricular septum (IVS) become the dividing plane between the great vessels. The mitral valve echoes (MV) are continuous with those of the posterior wall of the posterior artery. There is a thin echo within the left atrium (LA), the significance of which is not determined.

July 1973

The American Journal of CARDIOLOGY

Volume 32

75

ECHOCARDIOGRAM IN d-TRANSPOSITION OF GREAT VESSELS--DILLON ET AL,

1

FIGURE 3. Echocardiogram of a patient with d-transposition of the great vessels and an interventricular septal defect. (See text for

discussion.) ventricular outflow tract, dips posteriorly as the pulmonic valve echo appears. In addition, the lower portion of the pulmonic valve echo and the crista lie in a plane that would run through the center of the aorta and aortic valve echoes. At no time in this echocardiogram are echoes from both semilunar valves recorded simultaneously. This echocardiogram was representative of all the normal children and those children with congenital heart disease and a normally related aorta and pulmonary artery. E c h o c a r d i o g r a m in d-transposition: Figure 2 is a representative echocardiogram of a patient with dtransposition of the great vessels. Obtained from a 5 day old infant, the recording was taken with the ultrasonic beam initially in the area of the base of the heart through both of the great vessels. The ultrasonic beam was then directed toward the ventricles

and eventually recorded the mitral valve echoes. By reading this echogram from right to left, one follows the cardiac structures from the ventricles into the great arteries. The interventricular septal echoes are continuous with those from the anterior wall of an artery that ordinarily would be the aorta. Within this artery one can see a box-like configuration of a semilunar valve that ordinarily would be the aortic valve. Anterior to the interventricular septum is a space representative of the right ventricle. As one traces the echogram from the area of the ventricles to the arteries, one records echoes from the semilunar valve in the anterior artery, which would ordinarily be a pulmonary artery. Thus, both semilunar valves are seen simultaneously and both great vessels run parallel to each other instead of the anterior artery dipping posteriorly at the level of the upper

FIGURE 4. Same patient. Echocardiogram of the great vessels taken during cardiac catheterization. Echoes from the aortic catheter (CATH) prove that the anterior artery is the aorta and not the pulmonary artery. 76

July 1973

The American Journal of CARDIOLOGY

Volume 32

ECHOCARDIOGRAM IN d-I"RANSPOSITION OF GREAT VESSELS--DILLON ET AL.

semilunar valve. In this echogram the upper artery was labeled aorta and the lower artery, pulmonary artery. Another finding t h a t was fairly consistent in our patients with transposition was a linear echo inside the left atrium. The identity of this echo is uncertain, but it probably originates from a pulmonary vein or the coronary vein. The significance of this finding was uncertain. To prove that the anterior artery was truly the aorta, we attempted to record echoes from the aortic catheter at the time of cardiac catheterization. Figure 3 is an echocardiogram from another patient with transposition of the great vessels. This echocardiogram was recorded by scanning from the ventricles into the base of the heart. This patient had a ventricular septal defect and, as one scanned to the base of the heart, the echoes from the interventricular septum disappeared. 9 At the base of the heart, one again observes 2 great vessels in which remnants of both semilunar valves can be seen. Figure 4 is an echocardiogram from the same patient at the time of cardiac catheterization. Again the pulmonary artery can be seen; within this artery is the echo from a stenotic pulmonic valve. The very strong, irregularly moving echo in the space above the pulmonary artery originates from the catheter placed in the aorta. T h i s demonstration proves that the upper artery was truly an aorta and not a pulmonary artery. In all 16 patients with transposition of the great vessels, superimposition of the great vessels was noted without intervening crista. The 2 great arteries ran parallel to each other, and the anterior artery did not dip posteriorly. In 14 of 16 patients, echoes from both semilunar valves could be recorded simultaneously. The relation of the interventricular septum and the dividing plane between the 2 arteries depended on the size of the left ventricle. With a normal left ventricle the interventricular septal echoes were at the same level as those from the anterior wall of the posterior artery. If the left ventricle was dilated, then the interventricular septal echoes were at a more anterior level. Figure 5 demonstrates the relation of the great arteries and the semilunar valves to the ultrasonic beam in both the normal situation and in transposition of the great vessels. Figure 5A shows that normally the 2 arteries cross; the pulmonary artery begins anteriorly but then dips posteriorly and bifurcates behind the aorta. In addition, the pulmonic valve is anterior, superior and to the left of the aortic valve. In this situation it is not possible to record echoes from both semilunar valves simultaneously. One would need to change the direction of the ultrasonic beam to record both the aortic valve (transducer position 1) and the pulmonic valve (transducer position 2). Figure 5B is a drawing of the relation of t h e great vessels and their respective valves in patients with transposition of the great vessels. The arteries are uncoiled and run parallel to each other rather than crossing. In addition, the position of the semilunar valves is altered so that it is now possible to record from both valves with the same ultrasonic beam.

DIAPHRAGM FIGURE 5. Drawings showing the relation of the great vessels and the ultrasonic beam in the normal situation (A) and in transposition of the great vessels (B). This illustration demonstrates that one must change the position of the transducer in order to record from both semilunar valves in normal subjects, whereas in patients with d-transposition of the great vessels echoes from both valves can be recorded with the same transducer position. The drawings also show that at the level of the pulmonic valve the pulmonary artery dips posteriorly as it bifurcates behind the aorta in the normal situation (A). With transposition (B), the vessels run parallel to each other,

Discussion Recordings of high quality are required to make the diagnosis of d-transposition from the echocardiogram. At times a repeat examination was necessary to obtain a record of high quality. In our study no child underwent sedation; we might have avoided some technical problems if mild sedation had been used. Experience has shown that children from 1 to 1 1/2 years of age are more difficult to examine than infants; after age 2 or 2 1/2, children seem to be more cooperative. The results of our study indicate that the echocardiographic finding of superimposition of the great vessels without intervening crista together with simultaneous recording of the semilunar valves is diagnostic for transposition of the great vessels. The superimposition without intervening crista seems to be due to the uncoiling and straightening of the great vessels that occur in transposition (Fig. 5). The si-

July 1973

The American Journal of CARDIOLOGY

Volume 32

77

ECHOCARDIOGRAM

IN d-TRANSPOSITION OF GREAT VESSELS--DILLON ET AL.

multaneous recording of echoes from both semilunar valves probably occurs because the pulmonic valve is inferior to its normal position and thus falls within the same ultrasonic beam as the aortic leaflets (Fig. 5). The origin of the posterior great artery, normally the aorta, on a plane equal to or posterior to the interventricular septum is an important finding in the differential diagnosis of cyanotic congenital defects such as tetralogy of Fallot, truncus arteriosus or double outlet right ventricle since, in these lesions, the origin of the artery is anterior to the interventricular septal plane. 9 The size of the 2 great vessels, especially the pulmonary artery, may vary at times; unfortunately we could not correlate the size with the pressure or flow within that vessel. Frequently the pulmonary arterial pressures were not obtainable. We believe that a small pulmonary artery probably represents obstruction to flow at the level of the pulmonic valve or in the subpulmonic region, but we could not prove this. Diagnostic value of echocardiography: The usually described contours of the aortic and pulmonic valves s,9,zl are frequently altered in transposition of

the great vessels. Normally the echocardiographic appearance of the 2 valves is distinctively different, but with transposition this distinctive appearance disappears. Thus, the classic echocardiographic configuration of a normal aortic or pulmonic valve cannot be relied on as an aid in determining whether the superficial or deep vessel is an aorta or pulmonary artery. We recently examined 2 adult patients who exhibited some degree of paralleling of the great vessels. The origin of their heart disease was not well documented, but they apparently did not have transposition. Echoes from the semilunar valves could not be recorded simultaneously. Although there were no exceptions among the children in our study, the finding of superimposition or paralleling of the great vessels may not in itself be diagnostic of transposition of the great vessels. However, if simultaneous semilunar valve echoes are recorded, along with the finding of superimposition, then diagnosis is probably more definitive. No patient w i t h / - t r a n s p o sition or situs inversus was included in our study. We caution that our criteria for these conditions might be altered or in error.

References 1. Edwards JE, Caby LS, Neufeld NN, el al.: Congenital Heart Disease, vol 1: Philadelphia, WB Sau'nders, 1965, p 365 2. Nadas AS: Pediatric Cardiology, second edition. Philadelphia, WB Saunders, 1963, p 609 3. Keith JD, Rowe RD, Vlad P: Heart Disease in Infancy and Childhood, second edition. New York, Macmillan, 1967, p 697-698 4. Abbott MES: Atlas of Congenital Cardiac Disease. New York, The American Heart Association, 1936, p 54-56 5. Liebman J, Cullum L, Belloc NB: Natural history of transposition of the great arteries: anatomy and birth and death characteristics. Circulation 40:237-262, 1969 6. Rashkind WJ, Miller WW: Creation of an atrial septal de-

78

July 1973

The American Journal of CARDIOLOGY

Volume 32

7. 8. 9. 10. 11.

fect without thoracotomy: palliative approach to complete transposition of the great arteries. JAMA 196:911-992, 1966 Braunwald E, Swan HJC: Cooperative study on cardiac catheterization. Circulation 37: suppl 3:1-113, 1968 Feigenbaum H: Clinical application of echocardiography. Progr Cardiovasc Dis 14:531-558, 1972 Feigenbaum H: Echocardiography. Philadelphia, Lea & Febiger, 1972, p 187-197 Hirata T, Wolfe SB, Pepp RL, et al: Estimation of left atrial size using ultrasound. Amer Heart J 78:43-52, 1969 Gramiak R, Nanda NC, Shah PM: Echocardiographic detection of pulmonary valve. Radiology 102:153-157, 1972