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Anomalous left coronary artery arising from the pulmonary artery with large left-to-right shunt in infancy
T h e Journal of P E D I A T R I C S
543
Anomalous left coronary artery arising from the pulmonary artery with large left-to-right shunt in infancy Anomalous origin of the left coronary artery from the pulmonary artery has been separated into the "infantile" type with poor collateral circulation and early death due to myocardial infarction and the "'adult" type in which there is well-developed collateral circulation and long survival. That this classification cannot be held too rigidly is demonstrated by the patient described, who developed a myocardial infarct in spite of the presence of a large collateral circulation.
Abraham M. Rudolph, M'D., ~ Norman L. Gootman, M.D., Neville Kaplan, M.D., and Michael Rohman, M.D. NEW
YORt%
N.
Y.
A N O M A Z O U S origin of the left coronary artery from the pulmonary artery is usually associated with the development of myocardial infarction and fibrosis within the first 6 months and death within the first year of life.i, 2 In rare instances, however, symptoms
From the Departments of Pediatrics, Radiology and Surgery, Albert Einstein College of Medicine, New York, N. Y. Supported by Grants-in-Aid from the Health Research Council of the City o[ New York (Contract No. U-1080), the Westchester Heart Association, and the United States Public Health Service Grant HE 05686. ~This work was performed during tenure as an Established Investigator of the American Heart Association. Address Professor of Pediatrics; Associate Professor of Philology, Detmrtment o] Pediatrlc~, Albert Einstein College of Medicine, Eastehester Road and Morris Park Avenue, New York 61, N. Y.
are absent in the early years of life, and a large collateral circulation between the right and left coronary artery is established. On the basis of these two symptom-complexes it has been suggested that the anomaly presents as two distinct types, an "infantile" and an "adult" type. a, 4 The "infantile" type of anomaly presents with symptoms of myocardial ischemia and infarction with minimal collateral circulation, whereas in the "adult" type myocardial ischemia is not evident, because of the large collateral circulation. The latter is characterized by a large flow from the right coronary artery via the left coronary artery into the pulmonary artery2 A left-to-right shunt is thus established, and continuous or diastolic murmurs may be audible due to the large blood flow through the collateral chan-
544
R u d o l p h et al.
October 1963
Fig, 1. Anteroposterior roentgenogram of chest preoperatively. nels. T h a t myocardial infarction may occur despite a large collateral circulation is illustrated by the following case report. T h e effect of surgical ligation of the anomalous coronary artery on the blood supply to the left ventricle is also discussed. CASE
REPORT
BMHC. S. C., a white female infant, was born uneventfully of a full-term normal pregnancy. The birth weight was 2.5 kilograms and the neonatal period was nnremarkable. At 6 months of age dyspnea and wheezing were noted and the child was thought to have bronchial asthma; this responded to 50 meg. of subcutaneous epinephANOMALOUS ORIGIN OF THE LEFT CORONARYARTERY BEFORE LIGATION
I
II
III
AVL
AVR
i-i {y~i+
i? vl
v3
Fig. 9. Electrocardiogram preoperatively.
AVF
rine. Excessive perspiration occurred, especially after feedings, and respiratory infections were frequent. At the age of 8 months the child was admitted to the Bronx Municipal Hospital Center with sudden onset of rapid breathing and pallor. Physical examination revealed a pale, somewhat undernourished, but well-deveIoped infant, weighing 5.4 kilograms, with rapid and labored respirations at 60 per minute. The liver was palpable 4 cm. below the right costal margin. Moist rfiles and diminished breath sounds were noted over both lung bases. The heart was enlarged to percussion in the sixth left intercostal space at the anterior axillary line. The first and second heart sounds were normal, a third sound was present at the apex, and no murmurs were audible. Femoral and radial pulses were equal. There was no edema. The admission roentgenograms of the chest demonstrated a marked enlargement of the left ventricle. The pulmonary vascular markings appeared normal and the lung fields were clear (Fig. 1). The electrocardiogram (Fig. 2) revealed evidence of left ventricular hypertrophy as well as deep Q waves in Lead I, aVl, V~, and V,. This was interpreted as being compatible with an anterolateral myocardial infarction. The child was given digoxin 75 meg. per kilogram in the first 24 hours and was maintained on 18 mcg. per kilogram per day. Dramatic improvement occurred during the next 2 days. Five days following admission cardiac catheterization was performed according to the methods previously described. G The child was premedicated with promethazine and chlorpromazine and tolerated the procedure well. The results are shown in Table I. Pressures in the superior vena cava, right atrium, right ventricle, and pulmonary artery were normal. There was a significant increase in oxygen saturation of 9 to 13 per cent at the pulmonary arterial level and the pulmonary to systemic flow ratio was 1.5:1 indicating a moderate left-to-right shunt. A patent ductus could not be entered from the pulmonary artery. A catheter was then inserted into the right femoral artery and passed retrograde into the ascending aorta and left ventricle. With the child in the right posterior oblique position, selective anglocardiography was performed through a catheter in the right ventricle. This showed a compressed, but otherwise normal, right ventricle and normal main and peripheral pulmonary vessels. The levocardiogram showed a markedly enlarged left
Volume 63 Number 4 part 1
Anomalous
le/t coronary artery
54 5
A-B Fig. 3, A and B. Angiogram from right ventricle showing small right ventricle and enormous left ventricle (lateral view). ventricle which formed the major part of the heart shadow. There was slow emptying of the left ventricle which changed little in size and shape between systole and diastole. The left atrium was slightly enlarged. Only faint visualization of the aorta was obtained, and the coronary arteries were not seen (Fig. 3, A and B). Aortograms through a catheter passed retrograde via the right femoral artery into the ascending aorta were performed in the anteroposterior and the right posterior oblique projections. Normal aortic valves and ascending aorta were demonstrated. There was prompt and dense filling of a dilated and tortuous right coronary ar-
tery. The left coronary artery was not seen arising from the aorta, but instead filled fi'om large anastomotic vessels and drained .into the main pulmonary artery (shown by the arrow) (Fig. 4, A and B). This was followed by dense opacification of the main pulmonary artery (Fig. 5). There was no evidence of a patent ductus arteriosus. Based on the clinical and catheterization findings the diagnosis of an anomalous left coronary artery which originated from the main pulmonary artery was made. Ligation of the anomalous vessel at it origin was advised. A left thoracotomy was performed; the anomalous left coronary was observed to arise from the
Table I
O~ sat. Superior vena cava 53 Right atrium 57 Right ventricle 53 Right pulmonary artery 66 Main pulmonary artery 66 A~rt~ 91 Left ventricle Systemic flow 3,9 L./min./M. 2 Pulmonary flow 6,0 L./min./M. 2
Preoperative Pressures Syst. ] Diast.
25 26
2 9
85 86
32 2.5
Mean
0~. sat.
2.5
69 7O 68 69 68 95 95
15 50
Postoperative Pressures S)~st. I Diast.
Mean 2.5 2.0
28 20
4 10
15
82
40
55
4.6 L./min./M. 2
546
Rudolph et al.
October 1963
with the diagnosis of a previous myocardial infarction. The chest was closed in routine fashion. The child had an uneventful postoperative course. All signs of congestive failure disappeared and digitalis was discontinued 3 months postoperatively. A roentgenogram 10 months postoperatively revealed a persistence of cardiomegaly with a prominent left ventricle (Fig. 6) and the electrocardiogram still showed changes but the Q waves had decreased in magnitude (Fig. 7). Cardiac catheterization was repeated 8 months postoperatively. This revealed normal pressures in the superior vena cava, right atrium, right ventricle, and pulmonary artery. There was no evidence of a left-to-right shunt as judged by blood oxygen saturation measurement (Table I). An aortogram (Fig. 8) from the root of the
Fig. 5. Angiogram from root of aorta showing filling of pulmonary artery via left coronary artery (posteroanterior view).
Fig. 4, A and B. Angiogram from root of aorta showing large right coronary artery and left coronary (marked by arrow) entering pulmonary artery (lateral view). pulmonary artery. As it was being isolated ventricular fibrillation occurred spontaneously. Brief cardiac massage resulted in a restoration of normal sinus rhythm without the use of electric countershock. The anomalous left coronary artery was rapidly doubly ligated wifh No. 2-0 silk sutures. An area of scar tissue 1.5 to 2 cm. in diameter was observed on the anterolateral surface of the left ventricle near the apex consistent
Fig. 6. Anteroposterior roentgenogram 10 months postoperatively.
Volume 63 Number 4 part 1
Anomalous left coronary artery
54 7
then via collateral blood vessels to the left coronary artery, a n d then to the p u l m o n a r y artery. I n effect, the left coronary artery behaves as an arteriovenous c o m m u n i c a t i o n between the a o r t a a n d p u l m o n a r y artery. T h e d e m o n s t r a t i o n of an increase in oxygen saturation at the p u l m o n a r y artery level is unusual. T h e only case r e p o r t e d is t h a t of Augustsson, Gasul, a n d Lundquist4 in w h i c h a 6 per cent increase was reported. O u r experience provides f u r t h e r evidence to indicate the course of blood flow is r e t r o g r a d e in the left coronary artery.
Fig. 7. Electrocardiogram 10 months postoperatively. aorta demonstrated the right coronary artery and diffuse collateral vessels. The left main coronary artery was not visualized and there was no evidence of a shunt since the pulmonary artery did not opacify. The child has continued to grow normally and is free of symptoms. She was seen at 2 years of age, at which time there was a relative reduction of heart size (Fig. 9). The electrocardiogram still revealed a persistence of the infarct pattern with Q waves in I, aVL, V~, and V 6 as well as left ventricular hypertrophy as indicated by tall R wave voltages in Vs, V 6.
Fig. 8. Angiogram from root of aorta 8 months postoperatively showing large right coronary artery, no filling of left coronary or pulmonary artery, and poor vascularity of left ventricnlar myocardium.
DISCUSSION A n o m a l o u s origin of the left coronary artery from the p u l m o n a r y artery is rare. Recent reviews 4, 7, 8 describe the characteristic clinical signs of this a n o m a l y a n d have stressed the i m p o r t a n c e of early diagnosis and surgical t r e a t m e n t . E d w a r d s 5 a n d m o r e r e c e n t l y Sabiston, Neill, a n d Taussig s and Apley, H o r t o n , and Wilson 9 h a v e defined tht h e m o d y n a m i c alterations in this condition. T h e y have demonstrated t h a t the direction of the blood flow in the a n o m a l o u s left c o r o n a r y is r e t r o g r a d e into the p u l m o n a r y artery. Thus, blood flows from the a o r t a to the right coronary artery,
Fig. 9. Anteroposterior roentgenogram 14 months postoperatively.
54 8
October 1963
Rudolph et al.
On the basis of the size of shunt, this disorder has been classified into the "infantile" and "adult" types. 3, 4 In this classification, the "adult" type is characterized by an extensive collateral circulation. These authors postulate that this large collateral circulation results in an adequate myocardial blood supply and prevents myocardial ischemia and myocardial infarction. The "infantile" type has minimal collateral circulation, resulting in a limited blood supply to the myocardium with resultant ischemia and infarction. These latter patients usually show early decompensation and die during the first year of life. T h a t this classification cannot be rigid is demonstrated by our patient. The patient presently being discussed does not conform to either the "adult" or "infantile" types. Despite the presence of a large collateral circulation and a large left-to-right shunt as demonstrated by oxygen saturation and angiography, marked myocardial ischemia with an infarct developed. It is evident, therefore, that the presence of a large collateral circulation does not necessarily imply an adequate myocardial blood supply. The myocardial ischemia may be related to a low perfusion pressure in the vessels supplying the myocardium resulting from run-off through the collateral vessels into the low resistance pulmonary circulation. It is postulated that the lack of symptoms in early infancy is probably due to high pulmonary vascular resistance during this period. Pulmonary vascular resistance is elevated during the early weeks of life, thus tending to minimize a left-to-right shunt through the left coronary artery and to maintain a high perfusion pressure to the myocardium. Concomitant with the fall in the pulmonary vascular resistance, the arteriovenous shunt increases and results in reduction of the effective perfusion of the myocardium. On the basis of these considerations, it would not appear advisable to consider the "infantile" and "adult" types of the disorder as separate specific entities, but rather as parts of a spectrum. The young infant with high pulmonary vascular resistance would have good coronary perfusion and no symp-
toms. In later infancy, should an adequate collateral circulation not be established, myocardial ischemia with infarction may result. If a collateral circulation is established, myocardial ischemia may be reduced, but infarction may still occur. Should good collateral circulation develop, an arteriovenous fistula may result, but myocardial blood supply may or may not be adequate to prevent ischemia. It is also possible that the infant may suffer a small infarct and then develop a large collateral circulation with clinical manifestations of an arteriovenous shunt. Since a large arteriovenous shunt may occur in infancy, the term "adult type" is not suitable for the disorder presenting with these features. The suggested surgical treatment of this condition, ligation of the anomalous left coronary at its origin from the pulmonary artery, has been discussed by others2 -a~ This is based on consideration of the hemodynamic alterations described; ligation may produce better perfusion of the myocardium by preventing run-off into the collateral circulation, and thus effectively increase blood supply to the myocardial tissue. Even though surgery is performed, fibrosis and myocardial damage may have been sufficiently extensive as to make complete recovery impossible. The postoperative examinations in the infant presented showed a persistence of cardiomegaly and electrocardiographic changes for at least 1 year, and tile angiographic studies still revealed a paucity of coronary vessels supplying the left ventricle. Marked clinical improvement resulted from the surgical procedure and the child is now symptom free and developing normally. In view of the demonstrated impairment of blood supply to the left ventricle, the prognosis m u s t still remain guarded. No information is at present available regarding the development of an adequate coronary arterial supply to the left ventricle following ligation of the anomalous artery. SUMMARY
An infant with anomalous origin of the left coronary artery arising from the pulmonary artery is presented.
Volume 63 Number 4 part 1
A large collateral circulation between the right a n d left coronary arteries h a d developed as d e m o n s t r a t e d by cardiac catheterization a n d angiography. This was insufficient to prevent myocardial infarction. These observations indicate that the differentiation of the lesion into "adult" a n d "infant" types on the basis of the degree of collateral circulation is not justified. Ligation of the left coronary artery resulted in i m p r o v e m e n t of the clinical condition, but future prognosis must be guarded.
Anomalous le[t coronary artery
4.
5. 6. 7.
8.
9. REFERENCES
1. Nadas, A. S.: Pediatric cardiology, Philadelphia, 1957, William B. Saunders Company. 2. Keith, J. D., Rowe, R. D., and Vlad, P.: Heart disease in infancy and childhood, New York, 1958, The Macmillan Company. 3. Gouley, B. A.: Anomalous left coronary artery
I0.
549
arising from the pulmonary artery (adult type), Am. Heart J. 40" 630, 1950. Augustsson, M. N., Gasul, B. M., and Lundquist, R.: Anomalous origin of the left coronary artery from the pulmonary artery (adult type), Pediatrics 29" 274, 1962, Edwards, J. E.: Anomalous coronary arteries with special reference to arteriovenous-like communications, Circulation 17" 1001, 1958. Rudolph, A. M., and Cayler, G. C.: Cardiac catheterization in infants and children, Pediat. Clin. North America 5" 907, 1958. Kuzman, W. J., Yuskis, A. S., and Carmichael, D. B.: Anomalous left coronary arising from the pulmonary artery, Am. Heart J. 57: 36, 1959. Sabiston, D. C., Neill, C. A., and Taussig, H.: The direction of blood flow in anomalous left coronary artery arising from the pulmonary artery, Circulation, 22: 591, 1960. Apley, J., Horton, R. E., Wilson, M. G.: The possible role of surgery in the treatment of anomalous left coronary artery, Thorax 12: 28, 1957. Case, R. B., Morrow, A. B., Stainsby, W., Nestor, J. O.: Anomalous origin of the left coronary. The physiologic defect and suggested surgical treatment, Circulation 17: 1062, 1958.
543
Anomalous left coronary artery arising from the pulmonary artery with large left-to-right shunt in infancy Anomalous origin of the left coronary artery from the pulmonary artery has been separated into the "infantile" type with poor collateral circulation and early death due to myocardial infarction and the "'adult" type in which there is well-developed collateral circulation and long survival. That this classification cannot be held too rigidly is demonstrated by the patient described, who developed a myocardial infarct in spite of the presence of a large collateral circulation.
Abraham M. Rudolph, M'D., ~ Norman L. Gootman, M.D., Neville Kaplan, M.D., and Michael Rohman, M.D. NEW
YORt%
N.
Y.
A N O M A Z O U S origin of the left coronary artery from the pulmonary artery is usually associated with the development of myocardial infarction and fibrosis within the first 6 months and death within the first year of life.i, 2 In rare instances, however, symptoms
From the Departments of Pediatrics, Radiology and Surgery, Albert Einstein College of Medicine, New York, N. Y. Supported by Grants-in-Aid from the Health Research Council of the City o[ New York (Contract No. U-1080), the Westchester Heart Association, and the United States Public Health Service Grant HE 05686. ~This work was performed during tenure as an Established Investigator of the American Heart Association. Address Professor of Pediatrics; Associate Professor of Philology, Detmrtment o] Pediatrlc~, Albert Einstein College of Medicine, Eastehester Road and Morris Park Avenue, New York 61, N. Y.
are absent in the early years of life, and a large collateral circulation between the right and left coronary artery is established. On the basis of these two symptom-complexes it has been suggested that the anomaly presents as two distinct types, an "infantile" and an "adult" type. a, 4 The "infantile" type of anomaly presents with symptoms of myocardial ischemia and infarction with minimal collateral circulation, whereas in the "adult" type myocardial ischemia is not evident, because of the large collateral circulation. The latter is characterized by a large flow from the right coronary artery via the left coronary artery into the pulmonary artery2 A left-to-right shunt is thus established, and continuous or diastolic murmurs may be audible due to the large blood flow through the collateral chan-
544
R u d o l p h et al.
October 1963
Fig, 1. Anteroposterior roentgenogram of chest preoperatively. nels. T h a t myocardial infarction may occur despite a large collateral circulation is illustrated by the following case report. T h e effect of surgical ligation of the anomalous coronary artery on the blood supply to the left ventricle is also discussed. CASE
REPORT
BMHC. S. C., a white female infant, was born uneventfully of a full-term normal pregnancy. The birth weight was 2.5 kilograms and the neonatal period was nnremarkable. At 6 months of age dyspnea and wheezing were noted and the child was thought to have bronchial asthma; this responded to 50 meg. of subcutaneous epinephANOMALOUS ORIGIN OF THE LEFT CORONARYARTERY BEFORE LIGATION
I
II
III
AVL
AVR
i-i {y~i+
i? vl
v3
Fig. 9. Electrocardiogram preoperatively.
AVF
rine. Excessive perspiration occurred, especially after feedings, and respiratory infections were frequent. At the age of 8 months the child was admitted to the Bronx Municipal Hospital Center with sudden onset of rapid breathing and pallor. Physical examination revealed a pale, somewhat undernourished, but well-deveIoped infant, weighing 5.4 kilograms, with rapid and labored respirations at 60 per minute. The liver was palpable 4 cm. below the right costal margin. Moist rfiles and diminished breath sounds were noted over both lung bases. The heart was enlarged to percussion in the sixth left intercostal space at the anterior axillary line. The first and second heart sounds were normal, a third sound was present at the apex, and no murmurs were audible. Femoral and radial pulses were equal. There was no edema. The admission roentgenograms of the chest demonstrated a marked enlargement of the left ventricle. The pulmonary vascular markings appeared normal and the lung fields were clear (Fig. 1). The electrocardiogram (Fig. 2) revealed evidence of left ventricular hypertrophy as well as deep Q waves in Lead I, aVl, V~, and V,. This was interpreted as being compatible with an anterolateral myocardial infarction. The child was given digoxin 75 meg. per kilogram in the first 24 hours and was maintained on 18 mcg. per kilogram per day. Dramatic improvement occurred during the next 2 days. Five days following admission cardiac catheterization was performed according to the methods previously described. G The child was premedicated with promethazine and chlorpromazine and tolerated the procedure well. The results are shown in Table I. Pressures in the superior vena cava, right atrium, right ventricle, and pulmonary artery were normal. There was a significant increase in oxygen saturation of 9 to 13 per cent at the pulmonary arterial level and the pulmonary to systemic flow ratio was 1.5:1 indicating a moderate left-to-right shunt. A patent ductus could not be entered from the pulmonary artery. A catheter was then inserted into the right femoral artery and passed retrograde into the ascending aorta and left ventricle. With the child in the right posterior oblique position, selective anglocardiography was performed through a catheter in the right ventricle. This showed a compressed, but otherwise normal, right ventricle and normal main and peripheral pulmonary vessels. The levocardiogram showed a markedly enlarged left
Volume 63 Number 4 part 1
Anomalous
le/t coronary artery
54 5
A-B Fig. 3, A and B. Angiogram from right ventricle showing small right ventricle and enormous left ventricle (lateral view). ventricle which formed the major part of the heart shadow. There was slow emptying of the left ventricle which changed little in size and shape between systole and diastole. The left atrium was slightly enlarged. Only faint visualization of the aorta was obtained, and the coronary arteries were not seen (Fig. 3, A and B). Aortograms through a catheter passed retrograde via the right femoral artery into the ascending aorta were performed in the anteroposterior and the right posterior oblique projections. Normal aortic valves and ascending aorta were demonstrated. There was prompt and dense filling of a dilated and tortuous right coronary ar-
tery. The left coronary artery was not seen arising from the aorta, but instead filled fi'om large anastomotic vessels and drained .into the main pulmonary artery (shown by the arrow) (Fig. 4, A and B). This was followed by dense opacification of the main pulmonary artery (Fig. 5). There was no evidence of a patent ductus arteriosus. Based on the clinical and catheterization findings the diagnosis of an anomalous left coronary artery which originated from the main pulmonary artery was made. Ligation of the anomalous vessel at it origin was advised. A left thoracotomy was performed; the anomalous left coronary was observed to arise from the
Table I
O~ sat. Superior vena cava 53 Right atrium 57 Right ventricle 53 Right pulmonary artery 66 Main pulmonary artery 66 A~rt~ 91 Left ventricle Systemic flow 3,9 L./min./M. 2 Pulmonary flow 6,0 L./min./M. 2
Preoperative Pressures Syst. ] Diast.
25 26
2 9
85 86
32 2.5
Mean
0~. sat.
2.5
69 7O 68 69 68 95 95
15 50
Postoperative Pressures S)~st. I Diast.
Mean 2.5 2.0
28 20
4 10
15
82
40
55
4.6 L./min./M. 2
546
Rudolph et al.
October 1963
with the diagnosis of a previous myocardial infarction. The chest was closed in routine fashion. The child had an uneventful postoperative course. All signs of congestive failure disappeared and digitalis was discontinued 3 months postoperatively. A roentgenogram 10 months postoperatively revealed a persistence of cardiomegaly with a prominent left ventricle (Fig. 6) and the electrocardiogram still showed changes but the Q waves had decreased in magnitude (Fig. 7). Cardiac catheterization was repeated 8 months postoperatively. This revealed normal pressures in the superior vena cava, right atrium, right ventricle, and pulmonary artery. There was no evidence of a left-to-right shunt as judged by blood oxygen saturation measurement (Table I). An aortogram (Fig. 8) from the root of the
Fig. 5. Angiogram from root of aorta showing filling of pulmonary artery via left coronary artery (posteroanterior view).
Fig. 4, A and B. Angiogram from root of aorta showing large right coronary artery and left coronary (marked by arrow) entering pulmonary artery (lateral view). pulmonary artery. As it was being isolated ventricular fibrillation occurred spontaneously. Brief cardiac massage resulted in a restoration of normal sinus rhythm without the use of electric countershock. The anomalous left coronary artery was rapidly doubly ligated wifh No. 2-0 silk sutures. An area of scar tissue 1.5 to 2 cm. in diameter was observed on the anterolateral surface of the left ventricle near the apex consistent
Fig. 6. Anteroposterior roentgenogram 10 months postoperatively.
Volume 63 Number 4 part 1
Anomalous left coronary artery
54 7
then via collateral blood vessels to the left coronary artery, a n d then to the p u l m o n a r y artery. I n effect, the left coronary artery behaves as an arteriovenous c o m m u n i c a t i o n between the a o r t a a n d p u l m o n a r y artery. T h e d e m o n s t r a t i o n of an increase in oxygen saturation at the p u l m o n a r y artery level is unusual. T h e only case r e p o r t e d is t h a t of Augustsson, Gasul, a n d Lundquist4 in w h i c h a 6 per cent increase was reported. O u r experience provides f u r t h e r evidence to indicate the course of blood flow is r e t r o g r a d e in the left coronary artery.
Fig. 7. Electrocardiogram 10 months postoperatively. aorta demonstrated the right coronary artery and diffuse collateral vessels. The left main coronary artery was not visualized and there was no evidence of a shunt since the pulmonary artery did not opacify. The child has continued to grow normally and is free of symptoms. She was seen at 2 years of age, at which time there was a relative reduction of heart size (Fig. 9). The electrocardiogram still revealed a persistence of the infarct pattern with Q waves in I, aVL, V~, and V 6 as well as left ventricular hypertrophy as indicated by tall R wave voltages in Vs, V 6.
Fig. 8. Angiogram from root of aorta 8 months postoperatively showing large right coronary artery, no filling of left coronary or pulmonary artery, and poor vascularity of left ventricnlar myocardium.
DISCUSSION A n o m a l o u s origin of the left coronary artery from the p u l m o n a r y artery is rare. Recent reviews 4, 7, 8 describe the characteristic clinical signs of this a n o m a l y a n d have stressed the i m p o r t a n c e of early diagnosis and surgical t r e a t m e n t . E d w a r d s 5 a n d m o r e r e c e n t l y Sabiston, Neill, a n d Taussig s and Apley, H o r t o n , and Wilson 9 h a v e defined tht h e m o d y n a m i c alterations in this condition. T h e y have demonstrated t h a t the direction of the blood flow in the a n o m a l o u s left c o r o n a r y is r e t r o g r a d e into the p u l m o n a r y artery. Thus, blood flows from the a o r t a to the right coronary artery,
Fig. 9. Anteroposterior roentgenogram 14 months postoperatively.
54 8
October 1963
Rudolph et al.
On the basis of the size of shunt, this disorder has been classified into the "infantile" and "adult" types. 3, 4 In this classification, the "adult" type is characterized by an extensive collateral circulation. These authors postulate that this large collateral circulation results in an adequate myocardial blood supply and prevents myocardial ischemia and myocardial infarction. The "infantile" type has minimal collateral circulation, resulting in a limited blood supply to the myocardium with resultant ischemia and infarction. These latter patients usually show early decompensation and die during the first year of life. T h a t this classification cannot be rigid is demonstrated by our patient. The patient presently being discussed does not conform to either the "adult" or "infantile" types. Despite the presence of a large collateral circulation and a large left-to-right shunt as demonstrated by oxygen saturation and angiography, marked myocardial ischemia with an infarct developed. It is evident, therefore, that the presence of a large collateral circulation does not necessarily imply an adequate myocardial blood supply. The myocardial ischemia may be related to a low perfusion pressure in the vessels supplying the myocardium resulting from run-off through the collateral vessels into the low resistance pulmonary circulation. It is postulated that the lack of symptoms in early infancy is probably due to high pulmonary vascular resistance during this period. Pulmonary vascular resistance is elevated during the early weeks of life, thus tending to minimize a left-to-right shunt through the left coronary artery and to maintain a high perfusion pressure to the myocardium. Concomitant with the fall in the pulmonary vascular resistance, the arteriovenous shunt increases and results in reduction of the effective perfusion of the myocardium. On the basis of these considerations, it would not appear advisable to consider the "infantile" and "adult" types of the disorder as separate specific entities, but rather as parts of a spectrum. The young infant with high pulmonary vascular resistance would have good coronary perfusion and no symp-
toms. In later infancy, should an adequate collateral circulation not be established, myocardial ischemia with infarction may result. If a collateral circulation is established, myocardial ischemia may be reduced, but infarction may still occur. Should good collateral circulation develop, an arteriovenous fistula may result, but myocardial blood supply may or may not be adequate to prevent ischemia. It is also possible that the infant may suffer a small infarct and then develop a large collateral circulation with clinical manifestations of an arteriovenous shunt. Since a large arteriovenous shunt may occur in infancy, the term "adult type" is not suitable for the disorder presenting with these features. The suggested surgical treatment of this condition, ligation of the anomalous left coronary at its origin from the pulmonary artery, has been discussed by others2 -a~ This is based on consideration of the hemodynamic alterations described; ligation may produce better perfusion of the myocardium by preventing run-off into the collateral circulation, and thus effectively increase blood supply to the myocardial tissue. Even though surgery is performed, fibrosis and myocardial damage may have been sufficiently extensive as to make complete recovery impossible. The postoperative examinations in the infant presented showed a persistence of cardiomegaly and electrocardiographic changes for at least 1 year, and tile angiographic studies still revealed a paucity of coronary vessels supplying the left ventricle. Marked clinical improvement resulted from the surgical procedure and the child is now symptom free and developing normally. In view of the demonstrated impairment of blood supply to the left ventricle, the prognosis m u s t still remain guarded. No information is at present available regarding the development of an adequate coronary arterial supply to the left ventricle following ligation of the anomalous artery. SUMMARY
An infant with anomalous origin of the left coronary artery arising from the pulmonary artery is presented.
Volume 63 Number 4 part 1
A large collateral circulation between the right a n d left coronary arteries h a d developed as d e m o n s t r a t e d by cardiac catheterization a n d angiography. This was insufficient to prevent myocardial infarction. These observations indicate that the differentiation of the lesion into "adult" a n d "infant" types on the basis of the degree of collateral circulation is not justified. Ligation of the left coronary artery resulted in i m p r o v e m e n t of the clinical condition, but future prognosis must be guarded.
Anomalous le[t coronary artery
4.
5. 6. 7.
8.
9. REFERENCES
1. Nadas, A. S.: Pediatric cardiology, Philadelphia, 1957, William B. Saunders Company. 2. Keith, J. D., Rowe, R. D., and Vlad, P.: Heart disease in infancy and childhood, New York, 1958, The Macmillan Company. 3. Gouley, B. A.: Anomalous left coronary artery
I0.
549
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