Introduction:
Ebstein’s anomaly is a relatively rare congenital heart disease due to
tricuspid valve malformation and right ventricular myopathy (1). This
anomaly is commonly seen with other cardiac anomalies such as atrial
septal defect (ASD), ventricular septal defect (VSD) and some types of
accessory pathways (2). Among them, presence of accessory pathways makes
patients susceptible to developing tachyarrhythmia such as paroxysmal
supraventricular tachycardias, atrial fibrillation and atrial flutter
that have been observed in 25 to 30 % of the patients (3).
Atrio-fascicular Mahaim (AFM) pathway is one possible associated
condition diagnosed in relation with Ebstein’s anomaly. This is
described as the presence of conducting pathways between the AV node in
RV and right bundle branch (4). The association between Ebstein’s
anomaly and Mahaim fibers is due to Mahaim fibers’ proximal end being
located near the lateral tricuspid annulus (5). Due to the risk of
arrhythmia, electrophysiological study is recommended before starting
therapeutic interventions for Ebstein’s anomaly.
ASD is another anomaly associated with Ebstein’s anomaly which needs
attention. In these patients, the shunt is usually right to left, which
increases with the age of the patient; the severity of the tricuspid
regurgitation and right ventricular function. Closure of this defect can
lead to increased central venous pressure and decreased cardiac output
due to reduced left ventricular preload (6). The age of onset of
symptoms is usually different and depends on the severity of the
tricuspid regurgitation; right ventricle function and associated
abnormalities. Hence, careful hemodynamic examination is recommended
before deciding to manage associated anomalies in these patients
because, the appropriate time for proper intervention and treatment is a
challenging issue and is related to many factors (2).
In this paper we report the case of a 32-year-old woman, a known case of
Ebstein’s anomaly with large ASD and concomitant atrio-fascicular Mahaim
pathway who successfully underwent ASD device closure with Cribriform
Amplatzer device and ablation of accessory pathway.Case presentation :
A 32-year-old female, known case of Ebstein’s anomaly and concurrent
Atrial Septal Defect (ASD), referred to our center with complaint of
frequent palpitation attacks. The patient was under medical treatment
and regular follow-up due to her stable condition. In basic
electrocardiography, we observed normal sinus rhythm and no evidence of
abnormalities.
For better evaluation, trans-esophageal Three-Dimensional (3D)
echocardiography (TEE) was done and revealed four secundum type ASDs in
different levels of inter-atrial septum (IAS) (1.4cm, 0.6cm, 0.4cm,
0.7cm), with multiple small fenestrations that caused left to right
shunt with appropriate rims for device closure (posterio-superior
rim:0.6cm, postero-inferior rim: 0.4 cm, antero-inferior rim: 2.3 cm)
and also there was a large stretched patent foramen ovale (PFO)
(0.3cm*1.23cm) with distance of about 1.1cm from ASD.(figure1). Other
findings of echocardiography were as follows: normal left ventricle (LV)
size with mild systolic dysfunction; severe right ventricle (RV)
enlargement and systolic dysfunction; functional RV/anatomical RV
ratio:70%, fractional area change (FAC):30%; apical displacement of
tricuspid valve (TV) septal leaflet: 11 cm/m2 and posterior leaflet: 3.3
cm/m2 with elongation of anterior leaflet. Mild to moderate tricuspid
regurgitation (TR) without pulmonary hypertension.
Because of the history of frequent palpitation, after consultation with
electrophysiology expert team, she was candidate for
electrophysiological study (EPS). In EPS, changes of electrocardiography
(ECG) to left bundle branch bloke (LBBB) pattern during rapid atrial
pacing with negative HV and the most fused AV and Mahaim potential in
the postero-lateral part of TV annulus area were observed. Furthermore,
two different narrow QRS tachycardia were also induced; the first one
was the atrial tachycardia (AT) from right postero-septal area with
cycle length of about 285 ms and HV and AH of about 45 and 115 ms
respectively with retrograde atrial activation with earliest A in the
HBE. The second was AT from infra-crista region with cycle length of
about 330 ms and HV and AH of about 45 and 115 ms respectively with
retrograde atrial activation and with earliest A in high right atrium
(HRA). Finally, EPS revealed that she had Mahaim accessory pathway
(Atrio-fascicular type) and Atrial tachycardia from postero-septal and
infra-crista regions that all of them were successfully ablated during
this procedure. Moreover, because of atrial fibrillation (AF) rhythm she
received external electrical DC shock and fully converted to sinus
rhythm.
After successful ablation of accessory pathways, since she was not
candidate for surgical correction of other structural heart defects and
morphological properties of ASD (suitable for device closure), she
underwent diagnostic and therapeutic catheterization. During
catheterization, hemodynamic study showed evidence of left to right
shunt via ASD with ratio of pulmonary to systemic blood flow (QP/QS):
1.6. Also left ventricular (LV) injection showed normal LV size with
mild systolic dysfunction; abnormal septal motion and also abnormal
shape of LV in favor of Ebstein’s anomaly. ASD closure was performed by
an Amplatzer Multi Septal Occluder Cribriform device of about 35mm
without any complication. There remained only a small
posterio-superiorly placed ASD about 2mm which had no hemodynamically
significant residual shunt. Figure 2 shows the final successful closure
of multiple ASDs using a single Cribriform Amplatzer
device.Discussion :
Ebstein’s anomaly is an uncommon congenital malformation with different
presentations (1) due to its heterogenic nature. These patients can
remain asymptomatic for years but the common symptoms are abnormal heart
rhythms; shortness of breath; fatigue and bluish discoloration of the
skin (7). A significant issue in patients with Ebstein’s anomaly is
identifying the appropriate time for therapeutic intervention.
Asymptomatic patients only need regular follow-up and evaluation for the
onset of symptoms. One of the most common manifestations of the disease
in adulthood is arrhythmia due to accessory pathways. Atrial
fibrillation; atrial flutter and ectopic atrial tachycardia are usually
seen in 40% of newly diagnosed adult patients. A distinct subgroup of
these atrioventricular accessory pathways is called Mahaim fibers that
seen in less than 2% of the normal heart population but it is present
in up to 13% of the patients with Ebstein’s anomaly (1).
In our case, due to the history of palpitations and the possibility of
preexcitation syndrome, at first, electrophysiological study was
performed which demonstrated atrio-fascicular Mahaim pathway in addition
to atrial fibrillation and atrial tachycardia which is a relatively rare
association in Ebstein’s anomaly. Furthermore, in these patients,
antiarrhythmic medication not only fails to effectively prevent
tachycardia recurrences, but also carries a high potential for
aggravating preexisting disturbances of physiological impulse generation
or conduction, and does not seem to be attractive to a mainly young
patient that requiring long term treatment. Hence, catheter ablation of
cardiac arrhythmias particularly those related to presence of accessory
pathways are the best choice for management of these patients (3).
Another cardiac anomaly known to be associated with Ebstein’s anomaly is
ASD with the prevalence of 80 to 94% (8). Although in most patients
there is a right-to-left shunt via ASD (6), but in ASD in our patient,
according to different paraclinical studies, had significant left to
right shunt that need intervention and with regard to lack of other
cardiac anomalies, we candidate her for trans-catheter closure. However,
if other heart defects are acknowledged, the only approach is surgery
(9).
Today, trans-catheter approach is the accepted and standard method for
ASD closure in non-Ebstein patients. For Ebstein patients who have
traditionally been managed by surgical approaches, trans-catheter
closure of ASDs seems more attractive due to fewer associated
complications including arrhythmias resulted from surgical scars (10).
Based on 3D echocardiography finding, she had multiple fenestrated ASDs,
and for closure of such ASDs, different strategies are available. Among
them we used Amplatzer Cribriform Multi-Fenestrated Septal Occluder
(Cribriform ASO) (Abbott Structural, Santa Clara, CA), which is a non
self‑centering device that have two large equal sized discs with small
linking waist diameter that can cover more than one adjacent defect
(11). In this way, usually we can close all the defects with a single
device and often in some case, a small residual defect is left behind
with hemodynamically nonsignificant shunt (12).
Another way for closure of fenestrated secundum ASD, that accounts for
10% of all ASDs, is simultaneous implantation of two or more devices or
use of atrial septostomy with balloon and tear the strands and then
placing a single larger atrial septal Occluder (ASO). Although these two
methods have been successfully performed in some cases, they have side
effects such as prolonged procedure time, risk of erosion and
embolization, which are not seen in the case of using a Cribriform
device (11).
In general, we noticed concurrent happening and presentation of
Ebstein’s anomaly with multiple small ASDs and a less common accessory
pathway known as Mahaim accessory pathway. Beside these, we also
challenged with a different kind of tachyarrhythmia known as Atrial
tachycardia (AT).
Our decision to perform this procedure was based on the patient’s
symptoms and the findings of echocardiography (appropriate rims and
defect size) and angiography (significant left-to-right shunt) and in
our patient, only a small postero-superiorly ASD of about 2mm remained
in our patient, which had no hemodynamically significant residual shunt
and we preferred to keep this defect as a backup because of the
underlying patient’s anatomy.
This was the first time we tried to correct multiple ASDs with such an
anatomy in a known case of Ebstein’s anomaly by a cribriform device.
There are few reports in the literature of trans catheter closure of the
septum defect in Ebstein patients, which includes a small ASD with left
to right shunt PFO (10).
Conclusion :
Our experience with the reported case indicated that percutaneous device
closure of multiple ASDs after percutaneous electrophysiological study
is useful in management of patients even with complex anatomy and
conductive pathway disorders and this should be as an available and
minimally invasive approach on the table for management of these
patients. It is worth mentioning that the important issue in these
patients is the accurate anatomical and hemodynamic evaluation with
different paraclinical methods. In general, timely intervention and
correct patient selection and type of intervention can help to reduce
complications and improve the prognosis of patients.
Data availability statement: The data that support the findings
of this study are available from the corresponding author upon
reasonable request.
Authors Contribution: MA, ZK and AF managed the patient, MA
drafted the paper, IH and MK revised the draft. All authors read and
approved final version of the paper.
Ethical statement : We took informed consent of the patient for
reporting this case, additionally we ensured that her information would
not be disclosed.
Acknowledgements : We thank patient’s family for their agreement
and consent to report the case. We also appreciate kind staff of the
hospital for their scarifying during the present pandemics.