158 Br Heart J 1991;65:158-60 Two cases of left superior vena cava draining directly to a left atrium with a normal coronary Br Heart J: first published as 10.1136/hrt.65.3.158 on 1 March 1991. Downloaded from sinus Henry B Wiles Abstract left shunting at both the atrial and ventricular The most common variation in the levels (pulmonary vein 96%, left atrium 93%, thoracic systemic venous system is a left ventricle 93%, and femoral artery 86%). persistent left superior vena cava Both catheterisation and angiography draining to a coronary sinus. A rare showed a persistent left superior vena cava anomaly is a persistent left superior connected to the roof of the left atrium (fig 1). vena cava connecting directly to the left The left superior vena cava ran in front of the atrium. In this situation it is believed left pulmonary artery and was connected to that the coronary sinus must be absent. the normal left innominate vein at its junction This report describes two cases of a with the left subclavian vein. There was also a persistent left superior vena cava normal right superior vena cava and a patent draining to a left atrium with a normal foramen ovale. The catheter passed antero- coronary sinus. gradely from the left superior vena cava into the left atrium as well as retrogradely from the left atrium into the left superior vena cava. The embryological development of systemic The catheter also passed from the right atrium and pulmonary veins is complex and subject into the coronary sinus, which did not to considerable variation. The early, communicate with any systemic vein except symmetrical cardinal veins ultimately give rise the cardiac veins (fig 2). The pulmonary veins to the superior systemic venous channels were connected to the left atrium. while the splanchnic plexus of the foregut gives rise to the pulmonary venous channels. CASE 2 Most of the left sided cardinal system A nine month old infant had a complete disappears, leaving only the coronary sinus to atrioventricular canal, pulmonary hyper- http://heart.bmj.com/ drain the cardiac veins and a remnant known tension, and failed to thrive. He underwent as the ligament of Marshall. Many variations cardiac catheterisation before pulmonary and abnormalities of venous development artery banding. At catheterisation the right have been described.`3 One variation is the and left ventricular peak pressures were equal persistence of a left superior vena cava,4 which (70 mm Hg). Oxygen saturation data usually drains into the coronary sinus. A rare measured by oximetry showed a left to right abnormality is the presence of a persistent left shunt at the atrial and ventricular levels superior vena cava draining directly into the (mixed venous 63%, right atrium 81%, right on September 24, 2021 by guest. Protected copyright. left atrium.56 It is often stated that a persistent ventricle 85%, and main pulmonary artery left superior vena cava draining into the left atrium is associated with an absent coronary sinus. We describe two patients in whom a persistent left superior vena cava draining to the left atrium was associated with a normal coronary sinus. Case reports CASE 1 A two year old child with tetralogy of Fallot had cardiac catheterisation before elective surgical repair. His clinical course was Division of Pediatric unremarkable except for slowly progressive Cardiology, Medical University of South cyanosis. Haemodynamic evaluation during Carolina, South catheterisation showed an unrestrictive Carolina, USA ventricular septal defect (right and left H B Wiles ventricular peak pressures 90 mm Hg), Correspondence to infundibular and pulmonary valve stenosis Dr Henry B Wiles, Division of Pediatric (main pulmonary artery peak pressure 12 mm Cardiology, Hg), and unobstructed left ventricular outflow Medical University of South Carolina, 171 Ashley (right femoral artery peak pressure 110 mm Figure 1 Angiogram showing the connection of the Avenue, Charleston, persistent left superior vena cava (LSVC) to the roofof Hg). Oximetry did not show a left to right The catheter the SC 29425, USA. shunt (mixed venous 71% and main the left atrium (LA). passedfrom right Accepted for publication atrium through the right superior vena cava and left 15 November 1990. pulmonary artery 69%). There was right to innominate vein (Inn) into the left superior vena cava. Two cases of left superior vena cava draining directly to a left atrium with a normal coronary sinus 159 There was no bridging left innominate vein. The pulmonary veins entered the left atrium as normal. The postoperative course was complicated and the patient died 27 days after operation. Br Heart J: first published as 10.1136/hrt.65.3.158 on 1 March 1991. Downloaded from At necropsy the findings at catheterisation were confirmed: complete atrioventricular canal and a persistent left superior vena cava to the left atrium. In addition, a normal coronary sinus was found with normal connection to the right atrium. This coronary sinus was not connected to any systemic vein other than the cardiac veins. Discussion Embryological development of the systemic veins involves the umbilical, vitelline, and cardinal venous systems. The anterior and posterior cardinal veins join to form the right and left common cardinal veins which empty into the sinus horns and then into the primitive Figure 2 Angiogram showing that the normallyformed atria. Invagination of the sinus horns, which coronary sinus (CS) is separatefrom the left superior causes both the common cardinal veins to vena cava (seefig 1). The catheter course is inferior vena empty into the right atrium, and obliteration of cava, right atrium, patentforamen ovale, left atrium, left the anterior cardinal vein leaves the normal superior vena cava, innominate vein, right superior vena cava, right atrium, and mouth of the coronary sinus. coronary sinus, with absence of the left superior vena cava, as found in the mature heart.7 Many variations and abnormalities of 85%). Data were not collected to document this development have been reported. The the degree of right to left shunting. most common thoracic venous abnormality is Angiography and the catheter course the persistent left superior vena cava draining showed a persistent left superior vena cava into the coronary sinus as reported in 3-10% of connected to the roof of the left atrium. This patients with congenital heart disease.89 This vein ran in front of the left pulmonary artery variation in isolation results in no haemo- and was connected to the left subclavian vein. dynamic compromise. A more uncommon http://heart.bmj.com/ on September 24, 2021 by guest. Protected copyright. Figure 3 A theory to explain the association between a persistent left superior vena cava (LSVC) to left atrium and a normal coronary sinus. (A) The left superior vena cava retains a communication with the left atrium ("unroofed") while the coronary sinus develops normally. (B) If this communication persists and the left superior vena cava does not regress, then both a left superior vena cava to left atrium and coronary sinus can exist together. LA, left atrium; RA, right atrium; RSVC, right superior vena cava; LSVC, left superior vena cava; IVC, inferior vena cava; CS, coronary sinus. (Adaptedfrom Lucas R V. Anomalous venous connections, pulmonary and systemic. In: Adams FH, Emmanouilides GC, eds. Moss' heart disease in infants, children, and adolescents. 3rd ed. Baltimore: Williams and Wilkins, 1983:483.) 160 Wiles abnormality is the persistence of a left superior vein in this instance without a left innominate vena cava connecting directly to the left atrium. vein. "Vertical veins" and "levoatriocardinal This anomaly was found in about 7 5% ofcases veins" do not have these characteristics. In of persistent left superior vena cava,'0 and it addition, the coronary sinus was clearly seen by results in a small right to left shunt. This either angiography or direct visualisation. Br Heart J: first published as 10.1136/hrt.65.3.158 on 1 March 1991. Downloaded from lesion has little haemodynamic effect, mainly a Figure 3 shows a theory to explain this asso- variable degree of systemic cyanosis.7 ciation of left superior vena cava with left Various workers believe that the atrium and normal coronary sinus. A connec- embryological anomaly ofthe left superior vena tion between the left cardinal vein and left cava connecting into the left atrium cannot atrium remains (similar to an unroofed coron- exist with a normal coronary sinus.67"' ary sinus) while the distal coronary sinus Presumably a left superior vena cava is develops normally. The left superior vena cava produced when the left common cardinal vein retains this connection to the left atrium but and the left sinus horn are incorporated into the loses its connection to the coronary sinus. right atrium during invagination of the sinus There is no obvious reason for the coronary horns and the left atrium. Failure of this sinus to become involved when the left com- invagination allows the left superior vena cava mon cardinal vein retains a connection with the to remain connected to the left atrium and left atrium. makes development of the coronary sinus This report shows the association between impossible (fig 3). Ifthis were true then an atrial the rare anomaly of a persistent left superior septal defect of the coronary sinus type should vena cava to left atrium and a normal coronary be present in every case. This finding is not sinus. Both patients described had other present in all reported cases. cardiac malformations requiring catheterisa- Edwards and DuShane described one tion which showed the additional venous patient who had a connection to the left atrium, abnormality. We do not know whether this rare pulmonary veins, and systemic veins via a association ever occurs without other intracar- "levoatriocardinal vein".' This patient had diac malformations.