Origin of the Left Coronary Artery From the Right Pulmonary Artery

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1 JACC Vol. 3. No, 6 June 1984: Origin of the Left Coronary Artery From the Right Pulmonary Artery SAROJA BHARATI, MD, FACC,* NAKUL CHANDRA, MD,t LAWRENCE W. STEPHENSON, MD,t HENRY R. WAGNER, Mot, PAUL M. WEINBERG, MD, FACC,:!: MAURICE LEV, MD, FACC* Brown Mills and Neptune, New Jersey. Philadelphia and Hershev, Pennsylmnia Origin of the left coronary artery from the right pulmonary artery has rarely been documented. This is the first such case in a heart with an intact ventricular septum and paraductal coarctation of the aorta. Although an antemortem diagnosis was made and the anomalous left coronary artery was ligated, the patient, a 3V2 month old infant, died 1 day after surgery. Autopsy confirmed the diagnosis, but revealed that the left coronary artery was dominant. It is believed that the fatal outcome in the infant was, in part, due to the dominance of the left coronary artery and the effects of the coarctation on the already ischemic left ventricle. Origin of the left coronary artery from the right or left pulmonary artery is extremely rare. To date, we have found four reported cases (1-4). In three cases, the left coronary artery arose from the right pulmonary artery: in association with tetralogy of Fallot (I), ventricular septal defect (2) and common atrioventricular canal, aortic stenosis, patent ductus arteriosus and coarctation of the aorta (3). In a fourth case, in a patient with truncus arteriosus type II, the left coronary artery arose from the left pulmonary artery (4), This report concerns a case of origin of the left coronary artery from the right pulmonary artery, associated with coarctation of the aorta and intact ventricular septum. We believe that the case merits documentation because of its surgical import, Case Report This 31f2 month old Caucasian boy was the full-term product of a pregnancy complicated by maternal hypertension. He was born by caesarean section for breech presentation to a 28 year old female. At 3 weeks of life, he was From Congenital Heart and Conduction System Laboratory, Department of Pathology, Deborah Heart and Lung Center, Browns Mills, New Jersey:* Jersey Shore Medical Center, Neptune, New Jersey:t Departments of Pathology and Pediatrics, University of Pennsylvania, Philadelphia, Pennsylvania:\:: and Departments of Pathology, Temple University Medical School* and Pennsylvania State University Medical School*, The Milton S. Hershey Medical Center, Hershey, Pennsylvania. This study was aided by Grant HL from National Heart, Lung, and Blood Institutes, the National Institutes of Health, Bethesda, Maryland. Manuscript received October 31, 1983; revised manuscript received December 13, 1983, accepted December 15, Address for reprints: Saroja Bharati, MD, Congenital Heart and Conduction System Laboratory, Department of Pathology, Deborah Heart and Lung Center, Browns Mills, New Jersey ,,[') 1984 by the American College of Cardiology noted to be feeding poorly despite formula changes and he had multiple shuddering and crying episodes. No cyanosis was noted. One week before admission to the hospital, he developed a dry hacking cough and was treated with antibiotics. Four days before admission, he began to have episodes of coughing spells, crying and breath-holding. He was taken to a local hospital where a chest X-ray film showed a large heart. An electrocardiogram (Fig. I) showed an elevated ST-T wave segment in leads V5 and V6 and 6 mm Q waves in leads II, III and avf, compatible with infarction of anterolateral and inferior left ventricular walls. The echocardiogram revealed severe left ventricular dilation and poor contractility. An aortogram revealed the right coronary artery emerging from the aorta (Fig. 2A), which was considered to be of good size. An anomalous left coronary artery emerged from the right pulmonary artery (Fig. 2B). Cardiac catheterization and angiography showed poor left ventricular contractility with markedly elevated left ventricular end-diastolic pressure (12 mm Hg) and coarctation of the aorta. However, there was no systolic pressure gradient across the narrowed isthmus, probably because of reduced cardiac output. The pulmonary artery pressure was elevated (45110 mm Hg, mean 40) and there was no stepup in oxygen saturation at the pulmonary artery level The infant was transferred to the Children's Hospital of Philadelphia. On admission, physical examination revealed a pale, wasted, tachypneic infant with chest retractions. Auscultation revealed a positive S4 and a grade 3/6 holosystolic murmur of mitral regurgitation at the apex radiating to the axilla and left back. A thallium scan also was performed. Static images showed a large defect involving the anterolateral wall and extending /84/$3.00

2 1566 BHARATI ET AL. JACC Vol. 3. No.6 i mr. r.,.. ~.. ~ Ii, I Ii. 'I'i~ " " tf, Of! r r... I 1.. I' II. III avr ~::l Hjhi~! iiii Hn nn 'Hfi qn ~ ~!!::If.'; t. ~iti r' 1! t avl avf,i Ill!!U. p. Idl I!'!!::,;;; i1:.! if..!ei' ;i!i ~[ HIl l!!.! l ;!:l i:,' ::i! Itl' I:,!..I::t.: Vl V5 V6 Figure 1. Present case. Nine lead electrocardiogram showing deep and wide Q waves in leads II, III and avf, Vs and V 6 Marked ST elevation is seen in leads Vs and V6. to the inferior wall. The delayed images suggested that the anterolateral wall was ischemic rather than infarcted. Elevated creatine kinase (CK) levels also suggested myocardial infarction, (CK 716 U/liter, CK2-MB fraction 15%). Surgery. Because of the worsening clinical condition, it was decided to ligate the anomalous coronary artery or, possibly, disconnect it and anastomose it to the left subclavian artery. Correction of the coarctation of the aorta was also considered. The infant was operated on and the anomalous left coronary artery from the right pulmonary artery was ligated. There was immediate improvement on the electrocardiogram. The ST-T segments descended, although they did not become normal. Ligation rather than implantation was chosen because the left coronary artery was considered to be small. The aortic isthmus was also inspected and it was decided not to proceed with the resection because visual inspection did not suggest marked narrowing. The infant did well immediately after the surgery. The next day, however, he had an episode of supraventricular tachycardia and hypotension. With digoxin and cardiover- Figure 2. A, Aortogram showing single right coronary artery (arrow). B, Later phase of the same aortogram, showing the retrograde filling into the right pulmonary artery. The arrow points to the region ofthe pulmonary trunk. N = narrowing at the junction of the left subclavian artery with the descending aorta, suggesting coarctation of the aorta.

3 June 1984: BHARATI ET AL sion, he returned to normal sinus rhythm. A little later that day, he developed tachycardia with atrial flutter. An echocardiogram showed nonmoving anterior and posterior left ventricular walls. The same evening (I day after surgery) he became hypotensive, went into cardiac arrest and could not be resuscitated. Pathologic examination. Aside from the findings in the heart, the pathologic diagnosis was: I) pulmonary edema, atelectasis and hemorrhage, 2) fatty infiltration of the liver, and 3) submucosal edema and hemorrhage in the bladder. Heart. The heart was greatly enlarged, weighing 93.5 g in the fixed state. The apex was formed by the left ventricle. The right atrium and right ventricle were hypertrophied and enlarged. The tricuspid and pulmonary valves were normal. The left coronary artery emerged at the base of the origin of the right pulmonary artery (Fig. 3). The left coronary artery proceeded around the left side of the posterior aspect of the base of the pulmonary trunk (Fig. 4) and divided into three branches-the anterior descending, the ramus obtusi (oblique) and the left circumflex. The left circumflex branch formed the posterior descending branch. The main left coronary artery was ligated surgically at its base. The right coronary artery emerged from the right aortic sinus of Valsalva. After giving off the ramus acuti, it gave rise to several terminal small branches to the posterior wall of the right ventricle. The ductus arteriosus was probe-patent. The left atrium was hypertrophied and enlarged and showed distinct diffuse fibroelastosis. Although the mitral orifice was normal in size, the posterior leaflet was poorly developed. The chordae tendineae were abbreviated, and the anterior and posterior papillary muscles were fibrosed and situated more proximally than normal (Fig. 5). The left ventricle was enlarged, and its wall was thinner than normal, especially in the anterior wall (Fig. 5). The ventricular septum was intact. The endocardium revealed fibroelastosis throughout the septum and free walls and the myocardium showed areas of fibrosis grossly (Fig. 5). The aortic orifice was smaller than normal, but its valve was normally formed. The transverse aorta revealed distinct narrowing with a prominent circumferential ridge at the junction of the subclavian artery and the descending aorta. The descending aorta was outpouched at the junction ofthe ductus arteriosus. Histologically, the sections of the left ventricle showed old and recent inferolateral and anterior myocardial infarction. Figure 3. Origin of the left coronary artery from the right pulmonary artery. Arrow points to the mouth of the left coronary artery. LP = left pulmonary artery; PY = pulmonary valve. Case J. In the first reported case (I), a 3 '12 week old infant with tetralogy of Fallot had origin of the left coronary artery from the right pulmonary artery, just after the origin of the latter vessel. The left coronary artery gave off the Figure 4. External view of the left coronary artery as it passes along the posterior aspect of the base of the pulmonary trunk (PT). Note the probe lifting the left coronary artery as the vessel passes along this aspect. AD = left anterior descending coronary artery; LC = left circumflex coronary artery; LY = left ventricle. Discussion Reported cases. When the left coronary artery arises from the pulmonary artery. it is usually from the main pulmonary trunk. The three reported cases (1-3) in which the left coronary artery originated from the right pulmonary artery were described as follows.

4 1568 BHARATI ET AL. Figure 5. The open left ventricle (LV) revealing the fibrosis in the anterolateral and inferior walls and the septum, Also note the fibrosed anterior (APM) and posterior (PPM) papillary muscles situated more proximally than normal, Arrows point to the fibrosed areas in the anterolateral and inferior walls, A = aorta, anterior descending artery "which gave off a large interventricular branch. This branch ramified over its usual distribution as well as the apical region, extending to about one-third of the way along the inferior interventricular groove, The remainder of the left coronary artery appeared to ramify over its normal distribution" (I). Case 2. In the second case (2), a 3 year old girl had a ventricular septal defect and pulmonary hypertension. The left coronary artery arose from the right pulmonary artery, I cm distal to the bifurcation of the pulmonary trunk. This was diagnosed postmortem after the surgical closure of the ventricular septal defect. Case 3. In the third case (3), a 3 week old infant had persistent congestive heart failure and failure to thrive. Cardiac catheterization revealed the complete form of atrioventricular canal, mild sub- and supravalvular aortic stenosis, patent ductus arteriosus, coarctation of the aorta with marked hypoplasia of the isthmus and anomalous origin of the left main coronary artery from the inferior aspect of the proximal right pulmonary artery. The right coronary artery arose from the ascending aorta. The child was managed medically. Present case. Our case is the first of anomalous origin of the left pulmonary artery from the right pulmonary artery in association with intact ventricular septum and coarctation of the aorta. The marked fibrosis of the left ventricle may be related to the poor collateral circulation. In addition, because the coarctation of the aorta was not corrected at the time of ligation of the left coronary artery, this could have affected the left ventricular contractility postoperatively, especially because the left coronary artery was the dominant vessel. The recently and previously infarcted left ventricle probably was unable to function adequately in the presence of coarctation. The electrocardiographic or thallium scan findings are of interest in the four cases of origin of the left coronary artery from the right pulmonary artery. In our case, the electrocardiogram was somewhat atypical for anomalous left coronary artery, because it showed the infarct pattern best in the inferior wall. The thallium scan also suggested that the infarct was in the inferior wall and that the lateral wall was ischemic. In the first reported case (I) the electrocardiogram did not reveal any characteristics of ischemia. Likewise, in the second reported case (2), the electrocardiogram did not show any infarction pattern. Pulmonary hypertension may have preserved the coronary perfusion in that case. In contrast, Driscoll et al. (3) showed discordance of the QRS complex and T waves in the left lateral precordial leads, suggesting myocardial ischemia. Thus, evidence of ischemia may not be present, especially if there is a left to right shunt and pulmonary hypertension. Surgical management. In some selected cases, it may be possible to take the left coronary artery from the right pulmonary artery and anastomose it to the aorta. Because the main left coronary artery segment is long in these cases, the anastomosis may prove easier than in cases where the main left segment is short (as in origin of the coronary artery from the main pulmonary trunk). However, when a congenital lesion is associated with origin of the left coronary artery from the right pulmonary artery, producing pulmonary hypertension, removal of the congenital lesion will lower the pulmonary pressure and lessen the flow into the left coronary artery, complicating the surgical outcome, as in the case of Rao et al. (2). If complete repair is attempted, it might be better, if surgically feasible, to transfer the left coronary artery before repairing the tetralogy of Fallot or ventricular septal defect.

5 BHARATI ET AL. ORIGIN OF LEFf CORONARY ARTERY 1569 References I. Masel L. Tetralogy of Fallot with origin of the left coronary artery from the right pulmonary artery. Med J Aust 1960; 1:213~7. 2. Rao BNS, Lucas RV Jr, Edwards JE. Anomalous origin of the left coronary artery from the right pulmonary artery associated with ventricular septal defect. Chest 1970;58: Driscoll OJ. Garson A Jr, McNamara OG. Anomalous origin of the left coronary artery from the right pulmonary artery associated with complex congenital heart disease. Cathet Cardiovasc Oiagn 1982;8: Nora 11, McNamara OG. Anomalies of the coronary arteries and coronary artery fistula. In: Watson H, ed. Pediatric Cardiology vol. 17. London: Lloyd-Luke, 1968:297.