|Year : 2014 | Volume
| Issue : 2 | Page : 133-135
Tricuspid atresia with congenital advanced AV nodal block: An extremely rare association
Debabrata Bera, Biswajit Majumder, Ashfaque Ahmed, Deepesh Venkatraman
Department of Cardiology, Radha Gobinda Kar Medical College, Kolkata, West Bengal, India
|Date of Web Publication||3-Oct-2014|
Department of Cardiology, Radha Gobinda Kar Medical College, Kolkata - 700 004, West Bengal
Source of Support: None, Conflict of Interest: None
Tricuspid atresia (TA) is a cyanotic congenital heart disease (CHD) with incidence of 0.06/1000 live birth with a prevalence rate of 1-3% of all CHDs. TA can be associated with either normally related (type I) or transposed great arteries (TGA) (type II and III) and can be associated with/without ventricular septal defect (VSD) ± pulmonary stenosis (PS). An atrial level shunt through atrial septal defect/ patent foramen ovale (ASD/PFO) is essential for life. Although advanced atrioventricular (AV) block including complete heart block is seen in few CHDs like with congenitally corrected TGA (CC-TGA), AV discordance (isolated ventricular inversion), endocardial cushion defect (ECD), and left isomerism (polysplenia), it is not described in TA. Here, we report a neonate having TA with transposition with VSD, no PS (type IIc) who also had advanced heart block since intrauterine life. His mother was worked for autoimmune disease, but did not reveal any evidence of such.
Keywords: Congenital heart block, congenital AV nodal block, echocardiography, tricuspid atresia
|How to cite this article:|
Bera D, Majumder B, Ahmed A, Venkatraman D. Tricuspid atresia with congenital advanced AV nodal block: An extremely rare association. Nig J Cardiol 2014;11:133-5
|How to cite this URL:|
Bera D, Majumder B, Ahmed A, Venkatraman D. Tricuspid atresia with congenital advanced AV nodal block: An extremely rare association. Nig J Cardiol [serial online] 2014 [cited 2020 Apr 5];11:133-5. Available from: http://www.nigjcardiol.org/text.asp?2014/11/2/133/142120
| Introduction|| |
Tricuspid atresia (TA) is a relatively rare cyanotic congenital heart disease (CHD) with incidence of 0.06/1000 live birth with prevalence rate of 1-3% of all CHDs. TA can be associated with either normally related (type I) or transposed great arteries (TGA) (type II: d-TGA, type III: L-TGA) and can be associated with/without ventricular septal defect (VSD) ± pulmonary stenosis (PS). In all types, an atrial level shunt through ASD/PFO is essential for life.
Although advanced atrioventricular (AV) block including complete heart block is seen in few CHDs like with congenitally corrected TGA (CC-TGA or L-TGA), AV discordance (isolated ventricular inversion), endocardial cushion defect (ECD), and left isomerism (polysplenia),  it is not described as an association of TA.  Here, we report a neonate having TA with d-transposition with VSD, no PS (type IIC, the second most common type of TA), who also had congenital heart block detected since intrauterine life. His mother was worked for systemic lupus erythematosus (SLE), both ante- and postnatally, but did not reveal evidence of any autoimmune diseases.
| Case report|| |
A new born was sent for echocardiographic screening at 12 h of life because fetal echo done antenatally was suggestive of probable TGA with bradycardia. Baby was pink (though SpO2 = 90%), and he had a short systolic murmur. His electrocardiogram (ECG) showed high-grade AV block with AV dissociation and inferior QRS axis (around 90°). He did not have any other clinical markers of neonatal lupus. With possibility of CC-TGA in mind, echocardiography examination was started. It showed the following:
- Situs solitus [Figure 1]a. Single AV valve on left side. No AV valve on right side with atretic scar tissue seen [Figure 1]b
- Left atrium opening into a larger ventricular chamber, morphologically left ventricle (LV) (smooth, no moderator band, no septal attachment of chordae), on left side [Figure 1]c
- LV was connected to smaller but trabeculated right ventricle (RV) through a nonrestrictive VSD [Figure 1]b
- Short-axis view showed double circle and long-axis view showed both great arteries side by side with the bifurcating great artery pulmonary artery (PA) arising from LV [Figure 1]c and [Figure 2]a. Aorta was arising from RV [Figure 1]d
- No PS [Figure 2]b and c.
|Figure 1: Transthoracic echocardiography showing the following: (a) Subcostal view: Situs solitus. Aorta on left of vertebra. (b) Apical four chamber view: TA, VSD. (c) Parasternal long axis (PLAX) view: LV giving origin to PA (bifurcating great artery). (d) PLAX view: Side by side great arteries. RV giving rise to aorta. TA = tricuspid atresia, VSD = ventricular septal defect, PLAX = Parasternal long axis, LV = Left ventricle, RV = Right ventricle|
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|Figure 2: Transthoracic echocardiography showing the following: (a) Apical five chamber view: LV giving rise to PA (bifurcating great artery). (b) Apical five chamber view: No turbulence in RVOT (RV outflow tract). (c) Apical five chamber view: No significant gradient across RVOT, trivial pulmonary regurgitation (PR). (d) Subcostal view: Showing ASD (R to L shunt). LV = left ventricle, RV = Right ventricle, RVOT = Right ventricle outflow tract, R = Right, L = Left|
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On basis of above findings, final diagnosis of TA with d-transposition with VSD and no PS (second most common type of TA, type IIc) was made.
In the ECG, contrary to leftward axis of classical TA, he had inferior QRS axis. Escape rhythm was arising from multiple sites, having varying QRS morphology, but complete AV dissociation [Figure 3]. The advanced AV block was thought to be either a part of the CHD as an association itself or due to SLE in his mother (thus, a separate pathology).  As the fetus had bradycardia, detected during intrauterine life, mother was already worked up for autoimmune disease antenatally. It was negative for SLE. The autoimmune work up repeated now was again negative (Anti-Ro, Anti-La, and Rheumatoid Factor (RA) factor all negative) for both mother and baby.
|Figure 3: ECG showing high grade AV block, complete AV dissociation, inferior QRS axis, varying QRS morphology, and varying R-R interval, tall P waves. ECG = electrocardiogram, AV = atrioventricular|
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| Discussion|| |
Congenital heart block can be due to autoimmune or non-autoimmune causes. Among the autoimmune etiologies, the most common cause is SLE in mother, where cardiac injury in the fetus is believed to be due to active transport of maternal IgG auto-antibodies into the fetal circulation.  Otherwise, congenital heart block may be due nonautoimmune causes most commonly associated with congenital cardiac malformations or drugs. Among the CHDs, advanced AV block is found in 25% cases of CC-TGA. It is also reported in ECD and polysplenia syndrome. 
In literature, association of advanced heart block with TA is extremely rare.  Our index case had high-grade congenital AV block with TA (with d-TGA, IIc). On ECG, he did not have classical complete heart block, rather his R-R interval was varying (probably due to varying origin of escape beat) but consistently having AV dissociation and fixed P-P intervals with no relation of P and QRS complexes. He had inferior QRS axis (in contrast to left axis deviation in classical TA), which was probably due to escape rhythm arising from bundle of His, or, it also could be due to associated d-transposition of the great arteries (type II), where the frontal plane QRS axis is evenly divided between a leftward superior axis and an axis that is directed inferiorly and to the left. 
On the other hand, except the age old classical congenital heart block, other cardiac malformations like late onset cardiomyopathy (some of which display endocardial fibroelastosis) has been described in neonatal lupus.  But no literature describes TA with neonatal lupus (though our index case did not have any laboratory evidence of such).
This baby has multiple problems that were detected antenatally, and it was late for medical termination of pregnancy. Having such multiple problems, it's difficult to treat the baby surgically at this early age. Thus, the plan of management is initial medical management, followed by stepwise surgical approach.
| References|| |
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[Figure 1], [Figure 2], [Figure 3]