Abstract
Tetralogy of Fallot (TOF) is the most common form of cyanotic congenital heart disease beyond the age of 3 months. Complete heart block (CHB) is rare but a serious sequalae post-repair of TOF. We present a case of an 18-month-old child who developed late CHB after around 1 year of the corrective surgery of the congenital anomaly. On the regular follow-up visit, the patient assessment was unremarkable. However, there was bradycardia, 55 beats/min. The ECG showed complete atrioventricular dissociation. Echocardiogram was done and demonstrated severe tricuspid regurgitation (TR). The patient required a permanent pacemaker and he is currently well. We are presenting this case as a late unexpected CHB, with a possibility of progressive right-side dilatation as a contributing factor to CHB due to severe TR.
Keywords: arrhythmias, pacing and electrophysiology, valvar diseases, interventional cardiology
Background
The prevalence of tetralogy of Fallot (TOF) in the Saudi Arabia is about 5.7%.1 TOF accounts for about 7%–10% of cases of congenital heart disease and is one of the most common congenital heart lesions requiring intervention in the first year of life.2 Both genders are equally affected.3 Most patients with TOF undergo intracardiac repair as their initial intervention within the first year of age.4 However, some authors suggest that operating on TOF patients carries a lower risk of morbidity and mortality if done after the first year of life.5 Gerrah et al compared interventions in children weighing less than or equal to 4 kg in a retrospective study. They found that initial complete repair of TOF was associated with significantly less hospitalisation compared with the partial repair.6 Patients after intracardiac repair for TOF require a long-term follow-up, because they are at risk for the chronic postoperative sequelae which includes arrhythmias, pulmonary regurgitation with associated right ventricular volume overload, residual right ventricular outflow tract obstruction and sudden cardiac death.7 We report a case of a late complete heart block (CHB) post-intracardiac repair of TOF with summary of similar cases in the literature. Our case is unique in that CHB came much later than the usually reported (12 months) and we postulate that severe tricuspid regurgitation (TR) and progressive right-side dilatation may have been an important precipitating factor.
Case presentation
An 18-month-old boy known case of TOF, who was 1 year post-surgical repair, came to the cardiology clinic with his parents for a follow-up visit. The parents gave a medical history suggestive of a recent viral illness. There was no associated fever or loss of consciousness. There was no medical history of cardiac disease in the family.
At the age of 2 months, he had a medical history of cyanosis that was associated with crying. The parents took him to a hospital in their area where an echocardiogram was done. He was diagnosed there with TOF. At the age of 7 months, he had a surgical repair of TOF with a transannular patch.
Postoperatively, the patient developed junctional ectopic tachycardia (JET), bilateral pleural effusion, volume overload, which resolved during the hospital stay. JET responded well to cooling manoeuvres and increasing sedation. It subsided gradually over a course of 3 days after the operation. The bilateral effusion and volume overload were managed by fluid restriction and diuretics and resolved within 2 days.
Two weeks after the operation, the patient developed right-sided pneumothorax and chest tube was inserted, and the patient was kept for 2 days in-patient before the chest tube was removed. Postoperative ECG showed sinus rhythm and right bundle branch block (RBBB) (see figure 1). No other block type seen.
Figure 1.
This is an ECG of a 7-month-old boy post-tetralogy of Fallot repair showing right bundle branch block.
Investigations
ECG showed CHB with ventricular rate of 34/min (see figure 2). Echocardiogram showed depressed ventricular function, severe tricuspid regurgitation and small residual ventricular septal defect (VSD).
Figure 2.
This is an ECG of an 18-month-old boy showing complete heart block.
Treatment
The CHB was managed by undergoing a redo-sternotomy surgery with repair of regurgitating tricuspid valve with annuloplasty and commissurotomy and VVI permanent pacemaker was inserted. The patient was discharged home on the seventh day post-surgery.
Outcome and follow-up
Patient doing fine on follow-up visits.
Discussion
CHB in patients after surgical repair of TOF is a significant conduction abnormality which has been associated with an increased morbidity and mortality during the early and late postoperative period.8 Late-onset CHB has been reported in literature and it is a dangerous complication that necessitates a lifetime follow-up.9 10Heart block that occurs after 30 days of the surgery is considered late or delayed onset.11
Complete atrioventricular septal defect and TOF are the riskiest operations for the development of postoperative AV block.12
Potter et al described a 12-year-old boy with TOF who developed a transient heart block postoperatively, some years later had complete atrioventricular (AV) dissociation.13 Moss et al reported a 7-year-old boy who had complete AV dissociation immediately after definitive repair of TOF. After 4 years, the patient presented with nausea, vomiting dizziness and abdominal pain and was given symptomatic treatment for influenza. ECG was done, and it showed complete AV block with ventricular rate of
32/min.14
According to the literature, there are some predictors of delayed CHB after a surgical open-heart surgery for congenital heart disease including TOF. These predictors include the presence of a transient CHB immediately after the surgery, which our patient did not have include presence of an RBBB associated with left anterior hemiblock, occurrence of infra-Hisian block in response to atrial stimulation.10 11 13–15
Our patient developed JET postoperatively as it was documented in surgery notes. We included a figure for illustration. JET is a narrow complex tachycardia that usually arises near the AV node (see figure 3). It occurs mostly in the immediate postoperative period after congenital cardiac surgery.16 One study found that among patients with TOF, only 2% had JET.17
Figure 3.
Junctional ectopic tachycardia. Lead II shows competition between the sinus rate and the nodal tachycardia. After around the third beat, some sinus beats are conducted and followed by QRS complexes. Thereafter, the nodal tachycardia takes over resulting in a negative p-wave around the eighth beat, the proof of a junctional rhythm. Adopted under the creative commons license, brought to you for the educational purpose of our case (source link: https://commons.wikimedia.org/wiki/File:JEt_(CardioNetworks_ECGpedia).jpg).
Our patient had postoperative ECG that showed sinus rhythm and RBBB and no other degrees of AV block.
The occurrence of RBBB post-TOF surgical repair is attributed to the injury of the proximal right bundle branch as in courses along the rim of VSD, produced by repair of the VSD.
Kuzevska-Maneva et al reported the incidence of RBBB after repair of TOF was in all patients
(93.47% complete and 6.53% incomplete).18
We reviewed the literature about the late CHB in PubMed, Embase, Medline using the following keywords: Teratology of Fallot, Complete heart block, Heart block, AV block, AV dissociation and we ended up with 19 cases.10 13–15 17 19–22 Most of the cases with predictable CHB, 70%, had transient CHB. Seven cases, 35%, had RBBB prior to
CHB.11–13 Two cases, 10%, had infra-Hisian block in the form of HV prolongation due to atrial stimulation at 128 and 130 beats/min, respectively. RBBB is very common post-TOF repair and we believe it is not a strong predictor for developing CHB in post-TOF repair.15 Our patient did not have any of the serious predictors of late CHB mentioned. Severe TR and significant right atrial and ventricular dilatation may have played a role in our case and such a factor could be an additional predictor of CHB post-TOF repair. We reviewed all preoperative and postoperative echoes. All preoperative echocardiograms have shown minimal TR. In the first day postoperatively, an echocardiogram showed moderate TR which was made of a mild-moderate true TR jet and a second TR jet coming from a Garbode residual VSD left to right shunt going through the tricuspid valve leaflets. So, the described TR was most likely the result of the cardiac surgery performed.
In addition to that, our case is one of the youngest patients who suffered from CHB post-TOF repair. We calculated the mean age of presentation among the cases we reviewed, and it was 11.4 years. With the period between surgery and presentation with CHB to be 2.7 years. Some of the studies did not provide details about their patients including age and gender or the duration before the CHB occurrence.
Refer to table 1 for summary of the different cases with late CHB which were published to-date.
Table 1.
A summary table of cases of postoperative delayed complete heart block after tetralogy of Fallot repair
| Timing | # | Author | Age (year) and gender (male, female) | Did the patient have any of the predictors of late CHB | Postoperative transient CHB | Presence of RBBB | Presence of left anterior hemiblock associated with RBBB | Presence of infra-Hisian block in response to atrial stimulation | Duration between surgery and CHB |
| Delayed complete heart block after Fallot’s tetralogy repair | 1 | Lambert* | 13F | + | + | + | 4 years | ||
| 2 | Ainger* | 6M | 1 year | ||||||
| 3 | Cayler* | 16M | + | + | 8 years | ||||
| 4 | Goldberg* | 4M | + | + | |||||
| 5 | Fashena* | 18M | + | + | + | 8 years | |||
| 6 | Fashena* | 7M | 2 years | ||||||
| 7 | Potter13 | 14M | + | + | + | 1.5 years | |||
| 8 | Moss14 | 11M | + | + | + | + | 4 years | ||
| 9 | Moss | 8 1/2M | + | + | + | 3 years | |||
| 10 | Jue* | 7 1/2F | + | + | + | 1.5 months | |||
| 11 | Present case | 2 1/2M | + | 1 year | |||||
| 12 | Kaprawich17 | 25M | + | + | |||||
| 13 | Godman10 | 10 1/2 | 7 months | ||||||
| 14 | Godman | 8 1/2 | 5 months | ||||||
| 15 | Sethi19 | 17M | |||||||
| 16 | Bolens20 | + | + | 5 years | |||||
| 17 | Furuse21 | + | + | ||||||
| 18 | Friedli15 | + | + | 2 years | |||||
| 19 | Friedli | + | + | 5 years | |||||
| 20 | Sondheimer22 | + | + | + | 3.5 months |
*Cases were documented in the study done by Moss as personal communication in 1971.14
+, Criterion present; CHB, complete heart block; RBBB, right bundle branch block.
Learning points.
Complete heart block (CHB) is a rare but serious surgical complication that may arise after the repair of Fallot’s tetralogy.
The predictors of CHB have been studied in the literature and should be taken seriously.
The severe tricuspid regurgitation and the significant right atrial and ventricular dilatation may be an additional predicting predisposing factor of CHB post-tetralogy of Fallot repair.
Life-long follow-up is needed for postoperative CHB patient with especially ones with intracardiac repair.
We as clinicians should always think of the possibility of CHB in a patient presenting with lethargy and decreased activity after a repair of congenital heart anomaly.
Footnotes
Contributors: RW diagnosed the patient and followed him. He is the most responsible physician who was caring for the patient. RW discussed the importance of the case with JA and planned to prepare it for publication. RH and MB were involved in conducting the research including gaining the consent, collecting the data and writing. RW and JA encouraged RH and MB to include relevant data from important published research articles and use proper citation. JA added and modified the end point of conclusion addressing the possibly new risk factor of right ventricular dilatation as a cause for late complete heart block in this case. RW supervised the team and provided modifications. All authors discussed the results and contributed to the final manuscript.
Funding: The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests: None declared.
Provenance and peer review: Not commissioned; externally peer reviewed.
Patient consent for publication: Parental/guardian consent obtained.
References
- 1. Al-Mesned A, Al Akhfash AA, Sayed M. Incidence of severe congenital heart disease at the province of Al-Qassim, Saudi Arabia. Congenit Heart Dis 2012;7:277–82. 10.1111/j.1747-0803.2011.00614.x [DOI] [PubMed] [Google Scholar]
- 2. Anon. Report of the New England regional infant cardiac program. Pediatrics 1980;65:375–461. [PubMed] [Google Scholar]
- 3. Perloff JK. The clinical recognition of congenital heart disease. 4th ed. The Journal of Pediatrics 1995;126:460 10.1016/S0022-3476(95)70471-X [DOI] [Google Scholar]
- 4. Al Habib HF, Jacobs JP, Mavroudis C, et al. Contemporary patterns of management of tetralogy of Fallot: data from the Society of Thoracic Surgeons Database. Ann Thorac Surg 2010;90:813–20. 10.1016/j.athoracsur.2010.03.110 [DOI] [PubMed] [Google Scholar]
- 5. Waqar T, Riaz MU, Mahar T. Tetralogy of Fallot repair in patients presenting after Infancy: A single surgeon experience. Pak J Med Sci 2017;33:984 10.12669/pjms.334.12891 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6. Gerrah R, Turner ME, Gottlieb D, et al. Repair of Tetralogy of Fallot in Children Less Than 4 kg Body Weight. Pediatr Cardiol 2015;36:1344–9. 10.1007/s00246-015-1163-z [DOI] [PubMed] [Google Scholar]
- 7. Park CS, Lee JR, Lim HG, et al. The long-term result of total repair for tetralogy of Fallot. Eur J Cardiothorac Surg 2010;38:311–7. 10.1016/j.ejcts.2010.02.030 [DOI] [PubMed] [Google Scholar]
- 8. James FW, Kaplan S, Chou TC. Unexpected cardiac arrest in patients after surgical correction of tetralogy of Fallot. Circulation 1975;52:691–5. 10.1161/01.CIR.52.4.691 [DOI] [PubMed] [Google Scholar]
- 9. Liberman L, Pass RH, Hordof AJ, et al. Late onset of heart block after open heart surgery for congenital heart disease. Pediatr Cardiol 2008;29:56–9. 10.1007/s00246-007-9034-x [DOI] [PubMed] [Google Scholar]
- 10. Godman MJ, Roberts NK, Izukawa T. Late postoperative conduction distrubances after repair of ventricular septal defect and tetralogy of Fallot. Analysis by his bundle recordings. Circulation 1974;49:214–21. [DOI] [PubMed] [Google Scholar]
- 11. Kumar Das M. Modern pacemakers – present and future. USA: InTech, 2011. [Google Scholar]
- 12. Ayyildiz P, Kasar T, Ozturk E, et al. Evaluation of permanent or transient complete heart block after open heart surgery for congenital heart disease. Pacing Clin Electrophysiol 2016;39:160–5. 10.1111/pace.12778 [DOI] [PubMed] [Google Scholar]
- 13. Potter RT, Liu L, Maynard EP. Post-surgical heart block. Report of a case with bilateral bundle-branch block and changing rhythms. Br Heart J 1971;33:412–5. 10.1136/hrt.33.3.412 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14. Moss AJ, Klyman G, Emmanouilides GC. Late onset complete heart block. Newly recognized sequela of cardiac surgery. Am J Cardiol 1972;30:884–7. [DOI] [PubMed] [Google Scholar]
- 15. Friedli B, Bolens M, Taktak M. Conduction disturbances after correction of tetralogy of Fallot: are electrophysiologic studies of prognostic value? J Am Coll Cardiol 1988;11:162–5. 10.1016/0735-1097(88)90183-0 [DOI] [PubMed] [Google Scholar]
- 16. Haas NA, Plumpton K, Pohlner P, et al. Postoperative junctional ectopic tachycardia (JET). Zeitschrift für Kardiologie 2004;93:371–80. 10.1007/s00392-004-0067-3 [DOI] [PubMed] [Google Scholar]
- 17. Karpawich PP, Jackson WL, Cavitt DL, et al. Late-onset unprecedented complete atrioventricular block after tetralogy of Fallot repair: electrophysiologic findings. Am Heart J 1987;114:654–6. 10.1016/0002-8703(87)90768-X [DOI] [PubMed] [Google Scholar]
- 18. Kuzevska-Maneva K, Kacarska R, Gurkova B. Arrhythmias and conduction abnormalities in children after repair of tetralogy of Fallot. Vojnosanit Pregl 2005;62:97–102. 10.2298/VSP0502097K [DOI] [PubMed] [Google Scholar]
- 19. Sethi R, Khare R, Pradhan A, et al. Pentology of Fallot’s presenting with complete. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20. Bolens M, Friedli B. Progressive atrioventricular block after total correction of Fallot’s tetralogy, documented by repeat electrophysiological studies. Cardiology 1982;69:185–91. 10.1159/000173503 [DOI] [PubMed] [Google Scholar]
- 21. Furuse A, Wake K, Kotsuka Y, et al. Conduction disturbance and tachyarrhythmia in postoperative ventricular septal defect and tetralogy of Fallot. Jpn Circ J 1986;50:850–4. 10.1253/jcj.50.850 [DOI] [PubMed] [Google Scholar]
- 22. Sondheimer HM, Izukawa T, Olley PM, et al. Conduction disturbances after total correction of tetralogy of Fallot. Am Heart J 1976;92:278–82. 10.1016/S0002-8703(76)80107-X [DOI] [PubMed] [Google Scholar]