Ann Thorac Surg 2008;85:1403-1406. doi:10.1016/j.athoracsur.2007.12.036
© 2008 The Society of Thoracic Surgeons
Original Articles: Pediatric Cardiac
Isolated Atrioventricular Discordance: Surgical Experience
Rajesh Sharma, MCh*,
Ashutosh Marwah, MD,
Sejal Shah, MD,
Sunita Maheshwari, ABPC
Departments of Pediatric Cardiology and Cardiovascular Surgery, Narayana Hrudayalaya Institute of Medical Sciences, Bangalore, India
Accepted for publication December 10, 2007.
* Address correspondence to Dr Sharma, Pediatric Cardiac Surgery, Escorts Heart Institute and Research Centre, Okhla Rd, New Delhi, Pin 110025, India (Email: rsharmacvs{at}hotmail.com).
 |
Abstract
|
|---|
Background: Isolated ventricular inversion (atrioventricular discordance with ventriculoarterial concordance) is an extremely rare presentation of cyanotic congenital heart disease. The mode of presentation is akin to D-transposition of great arteries as systemic venous drainage and systemic arterial output connect to the same side of the cardiac septae, and pulmonary venous drainage and pulmonary arterial outflow to the opposite. Systemic oxygenation relies on intracardiac or extracardiac modes of mixing, as does survival, similar to transposition of the great arteries. Published literature is scant, mainly because of the rarity of this cardiac anomaly. We review our surgical experience with this lesion.
Methods: Five children with isolated ventricular inversion presented to us between the ages of 6 days and 22 months (mean, 12 months). Preoperative echocardiogram diagnosed large interventricular communication in 4, a patent ductus arteriosus in 4, and total anomalous pulmonary venous drainage with supracardiac connection in 1. One had associated narrowing of the left pulmonary artery origin. Four patients had atrial situs solitus, whereas 1 had right atrial isomerism. Three hearts had normally related great arteries whereas in 2, the aorta was to the right and anterior to the main pulmonary artery and arising in parallel fashion from the cardiac mass. Four children underwent trans–right atrial patch closure of the interventricular communications, with ligation of the patent ductus arteriosus. All 4 underwent a concomitant modified Senning’s repair. The fifth patient underwent repair of total anomalous pulmonary venous drainage with a Mustard-type repair. One needed concomitant repair of the mitral valve for injury to a free edge chorda sustained during closure of the ventricular defect.
Results: There was 1 early death. Complete heart block developed in 2 children, of which 1 needed permanent pacemaker insertion, whereas the other converted to sinus rhythm with intermittent atrial tachycardia. All survivors are doing well on follow-up, at a follow-up duration ranging from 6 to 48 months (mean, 18).
Conclusions: Repair of isolated atrioventricular discordance can be successfully achieved in the majority of patients presenting with this complex anomaly.
|
Introduction
|
|---|
Atrioventricular discordance or ventricular inversion is commonly associated with ventriculoarterial discordance and is then part of the complex of congenitally corrected transposition of the great arteries. Isolated ventricular inversion (isolated atrioventricular discordance) is an entity first described by Van Praagh and Van Praagh [1] in 1966. The malformation was characterized by an anatomical right atrium opening through a mitral valve into a morphologic left ventricle. The anatomical left atrium in turn opened into the morphologic right ventricle through the tricuspid valve. In contrast to congenitally corrected transposition, the connections at the ventriculoarterial level in isolated ventricular inversion were concordant, with the left ventricle connecting to the aorta and right ventricle to the pulmonary artery. Subsequently, in 1988, they described five different anatomic types of isolated ventricular inversion [2]. The differentiating features from the standard description accepted so far was a discovery of varying great arterial relationship, with the unifying feature that anatomical correction can be achieved by an atrial switch procedure with closure of any associated septal defect [6–9]. We describe our surgical experience with this entity.
|
Material and Methods
|
|---|
Patient Population
From 2002 to 2006, 5 patients were diagnosed to have isolated atrioventricular discordance; their ages ranged from 6 days to 22 months (mean, 12 months). Patient details and preoperative characteristics can be obtained from Table 1.
Evaluation
Preoperative determination of cardiac anatomy was entirely by transthoracic echocardiography. Clinical features and chest plain x-ray film were thought to be sufficient to decide operability in those presenting beyond 6 months of age. Hence, there was no indication for cardiac catheterization in any of these children.
Surgical Management
Closure of the intracardiac and extracardiac communications with venous rerouting to the appropriate ventricle was carried out on cardiopulmonary bypass with cardioplegic arrest. Except in 1 patient, all repairs were carried out on moderate hypothermia. In the single neonate in this experience, deep hypothermic circulatory arrest (broken into two parts of 30 and 40 minutes, respectively, for the total anomalous pulmonary venous connection [TAPVC] repair and the Mustard repair) had to be resorted to. Cardiopulmonary bypass was conducted with inflow through the ascending aorta and return through the individually cannulated cavas, except in the neonate in whom a combination of appendage cannulation and cardiotomy sucker bypass was utilized for venous return. Cardiopulmonary bypass times ranged from 126 to 186 minutes (mean, 140).
Ventricular Septal Defect Closure
After an appropriate atriotomy in the right-sided atrium, location of ventricular septal defect was confirmed through the right-sided mitral valve. In all 4 with associated ventricular septal defects, most of the defects could easily be approached through this route. Additional muscular defects were also easily identified through the relatively less trabeculated morphologic left ventricle. The single patient with a subaortic conus that separated the aortic and mitral valves had a difficult exposure of the aortic valve through the mitral valve. However, it was possible to achieve satisfactory closure of the ventricular septal defect even in this patient through the same route without additional ventriculotomy. The position of the conduction bundle location was assumed to be akin to that in congenitally corrected transposition of the great arteries in the anterosuperior edge of the septal defect [3, 10]. Care was taken to avoid the presumed area of the conduction bundle by placing sutures on the right ventricular aspect of the septum in the anterosuperior border [5].
Senning Repair
Native interatrial septum sufficed for the intra-atrial baffle utilized to separate the pulmonary veins from the mitral valve in all four Senning repairs. In situ pericardial modification of Senning repair was utilized for the pulmonary venous pathway to the right-sided mitral valve in all.
Mustard Repair
In the single neonate with heterotaxy and total anomalous pulmonary venous drainage, after connection of the pulmonary venous chamber to the back wall of the atrium, a baffle of native pericardium was used to divert the caval return to the left-sided tricuspid valve, with augmentation of the free wall of the right-sided atrium with homologous pericardium.
|
Results
|
|---|
Two patients had complete heart block, from which 1 recovered spontaneously before hospital discharge, whereas the other required permanent pacemaker implantation. None of the patients had any residual anatomical defects of consequence. However, the course in the intensive care unit was protracted in all except the 3-month-old patient. In the neonate with anomalously draining pulmonary veins, respiratory failure of unknown etiology developed in the postoperative period. He could not be weaned successfully from the ventilator. The other patients who were operated on beyond 1 year of age had to be on ventilator for prolonged duration to await subsidence of persistent pulmonary hypertension, which precluded early weaning. Ultimately, after a mean stay in the intensive care unit of 18 days (range, 4 to 48), all survivors were discharged. All survivors had good subsidence of pulmonary artery pressures—to normal level in the 3-month-old patient, and to half systemic pressures in the remaining 3.
|
Comment
|
|---|
Isolated atrioventricular discordance forms an example of a lesion for which careful evaluation of cardiac morphology is critical to a successful surgical approach. None of the patients in this series underwent angiography. The entire diagnosis was obtained by echocardiography. Sequential identification of the cardiac segments is necessary to diagnose correctly the various anatomic forms of atrioventricular discordance with ventricular concordance. The position of the atrioventricular valves (tricuspid valve being more apically displaced than mitral valve) and the septophillic attachment of the tricuspid valve can used to identify the atrioventricular valves correctly. Similarly, the left and right ventricles can be identified by the presence of the moderator band and coarse trabeculations in the right ventricle. In the group with normally related great arteries, aortomitral continuity was present (Fig 1). Presence of aorta right-sided atrioventricular valve (mitral valve) continuity without pulmonary left-sided atrioventricular valve (tricuspid valve) continuity was diagnostic of isolated atrioventricular discordance in the group with normally related great arteries with normal situs (Figs 1 and 2).
In patients with the subaortic conus, there was absence of aortomitral continuity. In both groups, the pulmonary valve had no relationship with the tricuspid valve.
View larger version (104K):
[in this window]
[in a new window]
|
Fig 1. Modified apical four-chamber view showing the atrioventricular discordance with ventriculoarterial concordance and crossing-over of outflow tracts. "V" indicates the position of the cursor on the transducer while performing the echocardiogram. (LV = left ventricle; LVOT = left ventricular outflow tract; PA = pulmonary artery; RA = right atrium.)
|
|
View larger version (94K):
[in this window]
[in a new window]
|
Fig 2. Modified short-axis view showing the normally related great arteries in a patient with isolated atrioventricular discordance. "V" indicates the position of the cursor on the transducer while performing the echocardiogram. (AO = aorta; PA = pulmonary artery; RVOT = right ventricular outflow tract.)
|
|
The same echocardiograpic findings of the "S, L, S" variety of ventricular inversion were first described by Snider and associates [5]. Subsequently, Pasquini and colleagues [2] described the other possible types of great artery relationships that might coexist with isolated ventricular inversion.
Great Arterial Relationship
Of the 5 patients, 3 had normally related great arteries, indistinguishable externally from that found in normal hearts. In the remaining 2 patients, the aorta was right and anterior to the main pulmonary artery, both exiting from the base of heart in parallel fashion. One of the latter had a bar of muscle (conus) separating the mitral valve from the aortic valve. The presence of the same was not confirmed surgically in the remaining patient, as his only associated cardiac defect was total anomalous pulmonary venous drainage and the intraventricular anatomy went uninspected. The above findings of normally related great arteries in 3 of the 5 patients (Figs 1 and 2) are at variance with the description of Bernasconi and associates [3] and Cavalle-Garrido and colleagues [4]. According to these authors, the defining feature in all the hearts with isolated atrioventricular discordance studied by them had the characteristic feature of parallel great arterial relationship.
Ventricular Septal Defect
The position of the conduction bundle in isolated ventricular discordance has not been described, but it is assumed that it would lie in a position akin to that in congenitally corrected transposition of great arteries because of the identical atrioventricular connections [3]. Closure of the ventricular septal defect through the anatomical left-sided right ventricle has been advocated by Pasquini and colleagues [2], as it would avoid the conduction bundle, which is situated on the left ventricular aspect of the interventricular septum. In this experience, however, we elected to perform closure of the ventricular septal defects through the mitral valve orifice, as excellent exposure of the entire defect was obtained through this route in 3 patients. Sutures were placed on the right ventricular aspect of the septum in the anterosuperior edge of the ventricular septal defect to avoid the conduction bundle, as advocated by de Leval and colleagues [11]. In 1 of the patients, however, a permanent complete heart block did develop despite this precaution. The fourth patient with the "S, L, D" variant (1 of the 2 with a subaortic conus, lack of aortomitral continuity, and externally right and anterior location of aorta) had a complex ventricular septal defect in that, although the inferior edge of the defect was clearly visible and within reach, the aortomitral discontinuity resulted in the aorta lying at a far distance superiorly. Inadvertent injury to a mitral chorda resulted as a consequence, necessitating a concomitant mitral valve repair. In this particular anatomy, retrospectively, we would have been better advised to use a combined right atrial and right ventricular approach, which would have avoided both mitral valve injury and probably the temporary complete heart block (and possibly also the ensuing atrial tachycardia) that complicated his postoperative recovery.
Atrial Switch
Isolated ventricular inversion forms one of the remaining indications for an atrial level switch today, the other one being as part of a double switch for congenitally corrected transposition. The Senning repair in our patients was without any problem, as all of those who underwent this option had a generous free wall of the right atrium and dilated pulmonary veins, secondary to a large intracardiac shunt. All had most of the cardiac mass situated on the left side (levocardia) without any apicocaval juxtaposition that is often seen in double discordance, and hence, none of the technical problems related to the Senning repair, characteristic of congenitally corrected transposition of great arteries, were encountered.
Pulmonary Hypertension
In the lone patient with supracardiac total anomalous pulmonary venous drainage to the superior venacava with atrioventricular discordance, the pulmonary venous chamber was connected to the posterior wall of the right-sided atrium. A modified Mustard type repair was then achieved, routing the pulmonary venous opening to the right-sided mitral valve and the systemic veins to the left-sided tricuspid valve. This baby had heterotaxy with right atrial isomerism and finally died after a protracted course in the intensive care unit secondary to respiratory failure and persistent pulmonary artery hypertension despite an unobstructed repair.
Three of the survivors had presented late with severe pulmonary hypertension and with history of repeated respiratory tract infections. All had features of pulmonary overcirculation by clinical criteria and chest roentgenogram. In view of the difficulty in determining operability in this subset of patients by cardiac catheterization (as in transposition of great arteries with ventricular septal defect presenting late), and as all were less than 2 years old, all were offered corrective surgery without any further attempt at determining operability. All had a significantly prolonged hospital stay secondary to varying degrees of pulmonary dysfunction after surgery, necessitating a prolonged period on a ventilator. The pulmonary artery pressures in all the survivors gradually came to normal or near normal in the others on follow-up.
We believe that the importance of reaching an accurate diagnosis of the anomaly cannot be overemphasized. Surgical repair is advised early in life, as the postoperative course in the younger patient would be more benign owing to fewer pulmonary issues. Lastly, the route of closure of ventricular septal defect should be carefully planned, keeping the possibility of postoperative complete heart block and iatrogenic mitral valve injury in mind. Presence of subaortic conus should prompt an additional approach through the left-sided ventricle, as advocated by Pasquini and colleagues [2].
|
References
|
|---|
- Van Praagh R, Van Praagh S. Isolated ventricular inversion: a consideration of the morphogenesis, definition and diagnosis of non-transposed and transposed great arteries Am J Cardiol 1966;17:395.[Medline]
- Pasquini L, Sanders SP, Parness I, et al. Echocardiographic and anatomic findings in atrioventricular discordance with ventriculoarterial concordance Am J Cardiol 1988;62:1256.[Medline]
- Bernasconi A, Cavalle-Garrido T, Perrin DG, Anderson RH. What is anatomically corrected malposition? Cardiol Young 2007;17:26-34.[Medline]
- Cavalle-Garrido T, Bernasconi A, Perrin DG, Anderson RH. Hearts with concordant ventriculoarterial connections but parallel arterial trunks Heart 2007;93:100-106.[Abstract/Free Full Text]
- Snider AR, Enderlein MA, Teitel DF, Hirji M, Heymann MA. Isolated ventricular inversion: two-dimensional echocardiographic findings and a review of literature Ped Cardiol 1984;5:27.
- Ranjit MS, Wilkinson JL, Mee RB. Discordant atrioventricular connexion with concordant ventriculoarterial connexion (so called "isolated ventricular inversion") with usual atrial arrangement (situs solitus) Int J Cardiol 1991;31:114.[Medline]
- McElhinney DB, Reddy VM, Silverman NH, Hanley FL. Intraatrial baffle repair of isolated ventricular inversion with left atrial isomerism Ann Thorac Surg 1996;62:1529.[Abstract/Free Full Text]
- Ostermeyer J, Bircks W, Krian A, et al. Isolated atrioventricular discordance: report of two surgical cases with isolated ventricular inversion J Thorac Cardiovasc Surg 1983;86:926.[Abstract]
- Kannan BRJ, Kamath KP, Rao SG, Kumar RK. Successful management of isolated ventricular inversion in an adult Ped Cardiol 2004;25:554.
- Gillette PC, Buch U, Mullins CE, Mc Namara DG. Electrophysiologic studies in patients with ventricular inversion and corrected transposition Circulation 1974;50:795.[Abstract/Free Full Text]
- de Leval MR, Bastos P, Stark J, et al. Surgical technique to reduce the risks of heart block following closure of ventricular septal defect in atrioventricular discordance J Thorac Cardiovasc Surg 1979;78:515.[Abstract]
This article has been cited by other articles:
|
|
|
|
 
S. Talwar, V. V. Nair, S. K. Choudhary, and B. Airan
Atrial Switch Operation in the Current Era: Modifications and Pitfalls
World Journal for Pediatric and Congenital Heart Surgery,
January 1, 2012;
3(1):
96 - 103.
[Abstract]
[Full Text]
[PDF]
|
|
|
Top
Abstract
Introduction
