ECHOCARDIOGRAPHIC ASSESSMENT OF TOTAL ANOMALOUS PULMONARY VENOUS CONNECTIONS IN PEDIATRIC PATIENTS

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1 Total nomalous Pulmonary Venous Connection ECHOCRDIOGRPHIC SSESSMENT OF TOTL NOMLOUS PULMONRY VENOUS CONNECTIONS IN PEDITRIC PTIENTS Meng-Luen Lee, Mei-Hwan Wu, 1 Jou-Kou Wang, 1 and Hung-Chi Lue 1 ackground and Purpose: Cardiac catheterization can be superfluous and risky for sick babies, infants, and young children with total anomalous pulmonary venous connection (TPVC). This study assessed the accuracy of echocardiography in the clinical assessment of pediatric patients with TPVC before cardiac surgery. Patients and Methods: total of 15 consecutive patients with TPVC treated between July 1, 1993, and December 31, 1999, were included in this retrospective study. Patients with TPVC with heterotaxy syndrome were excluded. We assessed this cardiac anomaly preoperatively using plain chest roentgenograms, echocardiography, and magnetic resonance imaging. combination of suprasternal, parasternal, subcostal, and apical four-chamber views and their tilting scans were employed for diagnosis and to trace the course of the anomalous pulmonary venous connection. Results: Interatrial right-to-left shunt via atrial septal defects were documented by two-dimensional echocardiography with color Doppler mapping in all 15 patients. Patent ductus arteriosus was found in six patients. Cardiomegaly with enlargement of the right atrium and the right ventricle could be seen on plain chest roentgenograms and by echocardiography in all but two patients with infracardiac TPVC. In all patients, the left innominate vein, coronary sinus or right atrium, and portal vein were the draining sites of supracardiac, cardiac, and infracardiac TPVC, respectively. pattern of continuous flow without phasic variation, which is suggestive of stenosis of the pulmonary vein, was found in two patients with infracardiac TPVC with obstruction. The surgical findings were reviewed and correlated well with those of the echocardiography. Conclusions: In infants and children with TPVC, the drainage sites and flow profiles of the pulmonary veins can be exactly determined by Doppler echocardiography preoperatively, which makes cardiac catheterization and angiocardiography unnecessary. (J Formos Med ssoc 2001;100:729 35) Key words: total anomalous pulmonary venous connection septum primum malposition defect pulmonary vein echocardiography cor triatriatum Total anomalous pulmonary venous connection (TPVC) is a congenital cardiac anomaly that can mimic many cardiac and non-cardiac conditions during infancy and the neonatal period [1]. It is an emergency cardiac lesion that requires immediate surgical intervention. Echocardiography with color Doppler mapping can provide detailed information about cardiac pathology in infants with TPVC. The need for more invasive procedures, such as cardiac catheterization, in infants and neonates with TPVC must be justified based on the association of the disease with other intracardiac lesions or the need for documentation of pulmonary venous obstruction. This study assessed the accuracy of echocardiography in assessing sick infants and children with TPVC. Division of Pediatric Cardiology, Department of Pediatrics, Changhua Christian Hospital, Changhua, and 1 Division of Pediatric Cardiology, Department of Pediatrics, College of Medicine, National Taiwan University Hospital, Taipei. Received: 16 pril Revised: 26 May ccepted: 4 September Reprint requests and correspondence to: Dr. Meng-Luen Lee, Division of Pediatric Cardiology, Department of Pediatrics, Changhua Christian Hospital, 135 Nanhsiao Street, Changhua, Taiwan. J Formos Med ssoc 2001 Vol 100 No

2 M.L. Lee, M.H. Wu, J.K. Wang, et al Patients and Methods From July 1, 1993, to December 31, 1999, TPVC was diagnosed in 15 consecutive patients initially at a primary care center. The patients were transferred to the cardiovascular center of a tertiary medical hospital for surgical correction. Patients with TPVC associated with heterotaxy syndrome were excluded from this study due to its frequent syndromic association with TPVC. The clinical manifestations, plain chest roentgenograms, echocardiograms, magnetic resonance images, and surgical notes of these 15 patients were reviewed. We listed the most convincing echocardiographic features in all types of TPVC. We compared echocardiographic features of coronary sinus TPVC with those of the cor triatriatum for differentiation. ll but one patient were less than 12 months old. Seconal (5 8 mg/kg/dose) administered per rectum was used for sedation. Suprasternal, parasternal, apical, and subcostal views were employed to explore the presence of TPVC [1, 2]. Cardiac catheterization was performed in two patients to rule out mixed TPVC. Magnetic resonance imaging was performed in one patient. C D Fig. 1. Plain chest roentgenograms and magnetic resonance imaging study of total anomalous pulmonary venous connection (TPVC). ) Cardiomegaly, prominent pulmonary trunk, and increased pulmonary vascular markings are seen in plain chest roentgenograms of patients with non-obstructive TPVC. ) snowman contour is visible on plain chest roentgenogram in a patient with supracardiac TPVC. Four right-sided arrows denote the right superior vena cava, and four left-sided arrows indicate a vertical vein. C) combination of normal heart size, passive pulmonary congestion, and a ground-glass appearance is seen on plain chest roentgenogram in a patient with obstructive infracardiac TPVC. D) descending vein (arrow) is shown penetrating the diaphragm and draining into the portal vein on magnetic resonance imaging study. 730 J Formos Med ssoc 2001 Vol 100 No 11

3 Total nomalous Pulmonary Venous Connection Results Clinical profiles The cardiac pathology of the 15 patients with TPVC is shown in the Table. The left innominate vein, coronary sinus or right atrium, and portal vein were the sites of drainage of all cases of supracardiac, cardiac, and infracardiac TPVC, respectively. Interatrial septal defect was found in all patients. Cardiomegaly, prominent pulmonary trunk, and increased pulmonary vascular markings were found on plain chest roentgenograms in 13 patients with non-obstructive TPVC (Fig. 1). snowman contour could be seen in four patients with supracardiac TPVC (Fig. 1). combination of normal heart size and passive pulmonary congestion, mimicking the condition of respiratory distress syndrome, was noted in two patients with infracardiac TPVC with obstruction (Fig. 1C). rterial blood gas showed severe hypoxemia (PaO mmhg) in two patients with obstructive infracardiac TPVC. Oxygen saturation ranged from around 80% to 90% on oxymeter in 13 patients with non-obstructive supracardiac and cardiac TPVC. Right atrial enlargement and right ventricular hypertrophy were found on electrocardiography and on frontal and lateral roentgenograms, in all patients except those with infracardiac TPVC. One patient with cardiac TPVC suffered from severe pulmonary hypertension, which was suprasystemic, and pulmonary vascular obstructive disease. He had a pulmonary-to-systemic resistance ratio of 0.9 due to a prolonged untreated course. Magnetic resonance imaging was employed in one patient to identify other associated intracardiac anomalies in addition to the infracardiac TPVC to the portal vein (Fig. 1D). Echocardiography The suprasternal long axis and its rotational views are most useful for detecting supracardiac TPVC (Fig. 2). Coronary sinus TPVC can be diagnosed over the parasternal long-axis view (Fig. 3), and its anterolateral tilting view. The only pitfall that can be encountered in echocardiography is cor triatriatum, which possesses a membrane much more vertical in the parasternal long-axis view and can be clearly differentiated from coronary sinus TPVC by anterior tilting of the probe, during which this membrane remains in the left atrium receiving the pulmonary venous blood. With the aid of color Doppler, a turbulent jet through the ostium of the separating membrane can be visualized. In patients with TPVC to the coronary sinus, the pulmonary venous confluence and its drainage can be visualized over the apical four-chamber view (Fig. 3), and its anteromedial tilting view, respectively (Fig. 3C). In case of cor triatriatum, a membrane partitioning the left atrium into two separate chambers can be seen horizontally in the apical four-chamber view. However, this horizontal membrane remains in the left atrium, in spite of the anterior tilting of the probe. turbulent jet via the orifice of the limiting membrane can be visualized with the aid of color Doppler. In patients with Table. Cardiac pathology of 15 pediatric patients with total anomalous pulmonary venous connection ge Sex Type Drainage Flow profile ssociated lesion 3 mo M Supracardiac LINV Phasic SD II 3 mo M Supracardiac LINV Phasic SD II, PD 2 mo M Supracardiac LINV Phasic SD II 5 mo M Supracardiac LINV Phasic SD II 2 d F Cardiac CS Phasic SD II, SVC, 5th arch 2 mo M Cardiac CS Phasic SD II 1 mo M Cardiac CS Phasic SD II, PD 9 d M Cardiac CS Phasic SD II, PD, VSD 7 mo M Cardiac CS Phasic SD II 6.5 mo M Cardiac R Phasic CVC, PD, SPMD 5 mo F Cardiac R Phasic SPMD 7 yr M Cardiac R Phasic SPMD, PVOD 4.5 mo M Cardiac R Phasic SPMD 3 d M Infracardiac PoV Non-phasic SD II, Pat, PD, TOF 1 mo M Infracardiac PoV Non-phasic SD II, PD M = male; LINV = left innominate vein; SD II = secundum atrial septal defect; PD = patent ductus arteriosus; F = female; CS = coronary sinus; SVC = bilateral superior vena cava; VSD = ventricular septal defect; R = right atrium; CVC = complete atrioventricular canal; SPMD = septum primum malposition defect; PVOD = pulmonary vascular obstructive disease; Pat = pulmonary atresia; PoV = portal vein; TOF = tetralogy of Fallot. J Formos Med ssoc 2001 Vol 100 No

4 M.L. Lee, M.H. Wu, J.K. Wang, et al 4). There was no evidence of pulmonary venous obstruction in patients with cardiac TPVC. In patients with TPVC directly to the right atrium, septum primum malposition defect can be visualized over the subcostal transatrial view. In patients with infracardiac TPVC, the course of drainage of the pulmonary venous confluence and its flow pattern can be easily detected over the subcostal transatrial view (Fig. 5). Discussion Fig. 2. Echocardiographic images of supracardiac total anomalous pulmonary venous connection in the suprasternal long-axis view. ) vertical vein (VV) that connects the pulmonary venous confluence (star) to the left innominate vein (arrow) and right superior vena cava (SVC) is seen. ) Pulmonary venous blood with a phasic profile from the vertical vein to the left innominate vein is seen, implying the absence of pulmonary venous obstruction. TPVC draining directly to the right atrium, there were characteristic changes to the septum secundum and the septum primum over the apical four-chamber view (Fig. 4). The pulmonary venous confluence can be visualized as an isolated chamber that separates the left atrium superolaterally. y moving the transducer in an anteroposterior plane, the pulmonary venous confluence can be traced to drain into the coronary sinus inferiorly (Fig. 3D). In patients with TPVC directly to the right atrium, there were characteristic changes to the septum secundum and the septum primum over the subcostal four-chamber view (Fig. 732 Thorough understanding of the development of the pulmonary venous system facilitates differentiation among TPVCs in which there are persistent connections between the splanchnic venous plexus, cardinal venous system, and the pulmonary venous plexus [3 5]. TPVC can mimic so many cardiac and noncardiac diseases with persistent pulmonary hypertension of the newborn that early differentiation and identification are essential before surgical intervention [6 9]. Clinically, patients with TPVC may have congestive heart failure and/or profound cyanosis resulting from a balance between the interatrial communication and the patency of pulmonary venous flow. dequacy of interatrial communication via the secundum atrial septal defect or septum primum malposition defect is suggestive of heart failure more than cyanosis. In this condition, anticongestive agents may have a better palliative effect than balloon atrial septostomy, which is important in the management of patients with TPVC before transfer to a tertiary medical center for total correction. However, in cases with pulmonary venous obstruction at the atrial level due to a small and restrictive atrial septal communication, emergency balloon atrial septostomy is mandatory for survival before surgery. Precatheterization measurement of the size of the interatrial defect and evaluation of the flow pattern via the defect by echocardiography are informative for decision making [9]. On physical examination, a systolic ejection murmur and/or a loud pulmonary component of the second heart sound can be heard over the pulmonary area in patients with isolated TPVC. Plain chest roentgenograms showed cardiomegaly and increased pulmonary vascular markings in patients with supracardiac and cardiac TPVC. snowman figure is found in patients with supracardiac TPVC to the left innominate vein [6 8]. Ground-glass lung fields, which mimic those seen in respiratory distress syndrome in cyanotic premature infants, were noted in our two cases of infracardiac TPVC with pulmonary venous obstruc- J Formos Med ssoc 2001 Vol 100 No 11

5 Total nomalous Pulmonary Venous Connection C D Fig. 3. Echocardiographic images in a patient with total anomalous pulmonary venous connection to the coronary sinus. ) Parasternal longaxis view shows a dilated coronary sinus (CS) as a bulging horizontal membrane that slightly parallels the anteromedial wall of the left atrium. ) pical four-chamber view shows the pulmonary venous confluence (star) that separates the left atrium laterally. C) View obtained by tilting anteromedially from the standard apical four-chamber view shows the pulmonary venous confluence (star), which can be traced to drain to the dilated CS. D) On the subcostal tilting or rotating view, the pulmonary venous confluence (star) can be traced to drain to the dilated CS. tion in the portal venous system. Electrocardiography showed right axis deviation, right atrial enlargement, and right ventricular hypertrophy in patients with supracardiac and cardiac TPVC. When a small left atrium and a relatively hypoplastic left ventricle are found on echocardiography, the possibility of malformation or underdevelopment of the inflow (pulmonary veins and mitral valve) or outflow (aortic valve, root, and arch) of the left heart should be considered. Echocardiography can distinguish mitral atresia with levoatriocardinal vein [10], hypoplastic left heart syndrome [11], Shone complex [12], and congenital pulmonary vein stenosis [13, 14] from TPVC by visualization of all (or some) of the pulmonary veins draining to the left atrium. In patients with isolated TPVC, there is a clear line of demarcation between the left atrium and the pulmonary venous confluence. Usually, a pulmonary venous confluence is situated posterior to the left atrium. Cor triatriatum can occasionally be mistaken for coronary sinus TPVC on echocardiography if the section planes are not in true profile. Various tilting procedures of the standard precordial and subcostal views can be employed to differentiate these two anomalies. Echocardiography can delineate the course and site of the anomalous pulmonary venous drainage as well as the obstruction of the pulmonary venous inflow [13 17]. Supracardiac TPVC can be clearly delineated on the suprasternal long-axis rotation cut. Infracardiac TPVC can be best delineated on the J Formos Med ssoc 2001 Vol 100 No

6 M.L. Lee, M.H. Wu, J.K. Wang, et al Fig. 4. Echocardiographic images of total anomalous pulmonary venous connection (TPVC) to the right atrium. ) pical four-chamber view showing that the superior limbic band of the septum secundum (straight arrow) is absent, and that the septum primum (five arrowheads) is malpositioned, deviated, and curved leftward, showing the possible morphogenesis of TPVC (4 curved arrows) to the right atrium (R) and a relatively small left atrium (L). ) Subcostal four-chamber view showing underdevelopment of the superior limbic band of the septum secundum (2 straight arrows) and malposition of the septum primum (5 arrowheads) in patients with TPVC (2 curved arrows) draining directly to the R. subcostal short-axis rotation cut. Coronary sinus TPVC can be detected and differentiated from cor triatriatum on the parasternal long-axis and apical four-chamber views and their tilt-axis views. Malalignment between the underdeveloped septum secundum and the leftward malpositioned septum primum, i.e., septum primum malposition defect, can contribute to the morphogenesis of TPVC draining directly to the right atrium [18]. non-phasic pattern of pulmonary venous flow can be detected by pulsed-wave Doppler in pa- tients with congenital pulmonary vein stenosis [13, 14], and TPVC with obstruction [15 17]. Pulsed-wave Doppler also shows the presence of acquired pulmonary venous obstruction following total correction for TPVC [19]. In conclusion, various types of TPVC can be accurately verified by echocardiography, except for mixed TPVC, which was not found in this series. The adequacy of interatrial communication or obstruction at the atrial level in TPVC should be assessed prior to Fig. 5. Echocardiographic images of infracardiac total anomalous pulmonary venous connection. ) Subcostal transatrial view: the pulmonary venous confluence (star) can be traced craniocaudally as a descending vein (arrow) that penetrates the diaphragm and drains into the portal vein. ) Continuous turbulent pulmonary venous flow with a non-phasic profile implies the presence of pulmonary venous obstruction. 734 J Formos Med ssoc 2001 Vol 100 No 11

7 Total nomalous Pulmonary Venous Connection balloon atrial septostomy. non-phasic pulmonary venous flow-characterized obstruction should be explored before and after surgery for TPVC. Underdevelopment or absence of the septum secundum and malposition of the septum primum contribute to the morphogenesis of TPVC directly to the right atrium. References 1. Smallhorn JF, Sutherland GR, Tommasini G, et al: ssessment of total anomalous pulmonary venous connection by two-dimensional echocardiography. r Heart J 1981; 46: Snider R, Serwer G: bnormal vascular connections and structures. In: Snider R, Serwer G, eds. Echocardiography in Pediatric Heart Disease. Chicago: Year ook Medical Publishers, Inc., 1990: utler H: n abnormal disposition of the pulmonary veins. Thorax 1952;7: Lucas RV Jr: nomalous venous connections, pulmonary and systemic. In: Moss J, dams FH, Emmanouillides GC, eds. Heart Diseases in Children, Infants and dolescents. altimore: Williams and Wilkins Co., 1977: Sissman NJ: Developmental landmarks in cardiac morphogenesis: comparative chronology. m J Cardiol 1970;25: onham Carter RE, Capriles M, Noe Y: Total anomalous pulmonary venous drainage. clinical and anatomical study of 75 children. r Heart J 1969;31: Delisle G, ndo M, Calder L, et al: Total anomalous pulmonary venous connection: report of 93 autopsied cases with emphasis on diagnostic and surgical considerations. m J Cardiol 1976;91: Hastreiter R, Paul MH, Milthan ME, et al: Total anomalous pulmonary venous connection with severe pulmonary venous obstruction. clinical entity. Circulation 1962;25: Meyer R: Total anomalous pulmonary venous return. In: Meyer R, ed. Pediatric Echocardiography.Philadelphia: Lea & Febiger, 1977: Lee ML, Wang JK, Lue HC: Levoatriocardinal vein in mitral atresia mimicking obstructive total anomalous pulmonary venous connection. Int J Cardiol 1994;47: Lee ML, Wu MH, Wang JK, et al: Flow characteristics in infants with hypoplastic left heart syndrome: an echocardiographic study. cta Paed Sin 1995;36: Shone JD, Edwards JE: Mitral atresia associated with pulmonary venous anomalies. r Heart J 1964;26: Huhta JC: Pediatric Imaging/Doppler Ultrasound of the Chest. Philadelphia: Lea & Febiger, 1986: Smallhorn JF, Panperi OH, enson L, et al: Pulsed Doppler assessment of pulmonary vein obstruction. m Heart J 1985;110: Smallhorn JF, Freedom RM: Pulsed Doppler echocardiography in the preoperative evaluation of total anomalous pulmonary venous connection. J m Coll Cardiol 1986; 8: Vick GW III, Murphy DJ, Ludomirsky, et al: Pulmonary venous and systemic ventricular inflow obstruction in patients with congenital heart disease: detection by combined two-dimensional and Doppler echocardiography. J m Coll Cardiol 1987;9: Wang JK, Lue HC, Wu MH, et al: Obstructed total anomalous pulmonary venous connection. Pediatr Cardiol 1993; 14: Van Praagh S, Carrera ME, Sanders S, et al: Partial or total direct pulmonary venous drainage to right atrium due to malposition of septum primum. natomic and echocardiographic findings and surgical treatment: a study based on 36 cases. Chest 1995;107: Lee ML, Wang JK, Lue HC: Visualization of pulmonary vein obstruction by pulmonary artery wedge injection and documentation by pressure tracings: report of one case with persistent wheezing following correction of total anomalous pulmonary venous connection. Int J Cardiol 1995;49: J Formos Med ssoc 2001 Vol 100 No