Vol.2, No.8, 460-462 (2013) Case Reports in Clinical Medicine
http://dx.doi.org/10.4236/crcm.2013.28121
Arrhythmogenic right ventricular cardiomyopathy
associated ventricular tachycardia misdiagnosed as
idiopathic right ventricular outflow tract origin and its
management
Xiangmin Shi*, Yutang Wang, Zhaoliang Shan
Department of Cardiology, The General Hospital of People’s Liberation Army, Beijing, China;
*Corresponding Author: shixm301cardiac@hotmail.com
Received 25 June 2013; revised 23 July 2013; accepted 20 August 2013
Copyright © 2013 Xiangmin Shi et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT
Arrhythmogenic right ventricular cardiomyopa-
thy/dysplasia (ARVC/D) is an autosomal domi-
nant genetic form of cardiomyopathy (CM), which
primarily affects the right ventricle (RV) and re-
sults in life threatening ventricular arrhythmias
and sudden cardiac death (SCD). Diagnosis is
difficult due to the broad spectrum of phenol-
typic variations, especially in the early stage.
Clinical suspicion should be raised in the setting
of refractory ventricular tachycardia originating
from the RV, and the final diagnosis could be
made based on the combination of electrocar-
diography, echocardiography, cardiac magnetic
resonance imaging (CMRI) and myocardial bi-
opsy. Implantable cardioverter-defibrillator (ICD)
implantation is an effective option for the treat-
ment of ARVC.
Keywords: Arrhythmogeni c Right Ventricular
Cardiomyopathy; Ventricular Ta chycardia; Cardi ac
Magnetic Resonance Imaging
1. INTRODUCTION
Arrhythm ogenic right ventricul ar cardiom yopathy (ARVC )
is one of the major causes of recurrent ventricular tachy-
cardia (VT) and sudden cardiac death in young people.
QRS morphology of VT and abnormalities of precordial
leads in sinus rhythm, in association with echocardi-
ography (UCG) and cardiac magnetic resonance imaging
(CMR), play an important role in early diagnosis of
ARVC. Presented herein is a 25-year-old male soldier
who suffered from recurrent episodes of palpitation and
presyncope due to VT, which resembled that of idio-
pathic right ventricular outflow tract (RVOT) origin, di-
agnosed as idiopathic RVOT VT in the presence of
echocardiographic normal heart and received oral ad-
ministration of metoprolol which eventually proved to be
ineffective. Meanwhile, surface 12 leads ECG indicated
persistent T wave inversion in V1-V4, which was sug-
gestive of ARVC, and following CMR scan confirmed
the diagnosis, and subsequently the patient was treated
with implantable cardioverter defibrillator (ICD).
2. CASE REPORT
A 25-year old male soldier without significant structural
heart disease and past medical therapy as well as family
history of sudden death, complained of recent onset of
recurrent palpitation and presyncope. Documented ECG
in local clinic revealed VT of left bundle branch block
(LBBB) morthology with a inferior axis (Figure 1(b)),
which was similar to VT arising from RVOT. Physical
examination and routine laboratory tests, including ESR,
CRP, cardiac-specific enzymes, D-dimer and serum elec-
trolytes, were within normal limits. ECG indicated Rs
pattern of QRS complex of normal width in lead V1-V3
and T wave inv er s ion in V1-V 4 ( Figure 1(a)), no epsilon
wave was seen. Firstly ARVC was suspected, however,
UCG ruled out the possibility in the setting of structur-
ally normal left and right ventricular. The patient was
primarily diagnosed as idiopathic RVOT-VT and rec-
ommended the radiofrequency ablation therapy, which
was declined by him latterly. In the following several
weeks, oral administration of metoprolol (25 mg, bid)
was prescribed to prevent the occurrence of ventricular
arrhythmia, however, he still complained frequent epi-
sode of palpitation with presyncope, and consequently
refered for hospitalization for further examin ation.
During hospitalization, repeated trans-thoracic UCG
Copyright © 2013 SciRes. OPEN ACCESS
X. M. Shi et al. / Case Rep orts in Clinical Med icine 2 (2013) 460-462 461
(a)
(b)
Figure 1. (a) ECG of sinus rhythm revealing T wave inversion
in lead V1-V4; (b) ECG documented ventricular tachycardia
with LBBB morphology and a inferior axis similar to idiopathic
RVOT-VT.
revealed normal dimension, thickness and ejection frac-
tion of dual ventricular chamber. He was still suspected
the diagnosis of A RVC due to the surface ECG findings,
Gadolinium-enhanced cardiac MRI (CMR) scan was
subsequently arranged for detailed assessment, which
revealed abnormality of right ventricular including focal
enlargement, akinetic motion with aneurysm of the free
wall (Figure 2), these findings were strongly suggestive
of ARV C.
Based on those clinical features, the soldier fulfilled
the clinical criteria for ARVC and ICD was implanted
consequently, during the follow-up, we observed ICD
treatment in the presence of VT, including anti-tachy-
cardia pacing (ATP) and shock delivery, the patient no
longer suffered presyncope.
3. DISCUSSION
ARVC is characterized by the progressive replacement
of right ventricular myocytes by fibrous or fibro-fatty
tissue which results in an area of slow conduction and
dispersion of refractoriness [1], leading to reentrant ven-
tricular tachyarrhythmia. Mutations in the desmosomal
proteins of the myocardium are believed to be attribut-
able to the pathog enesis of ARVC. However, the d iagno-
sis of ARVC is challenging due to its wide range of
manifestations ranging from an absence of symptoms to
cardiac arrest. Currently the 1994 Task Force Criteria
Figure 2. CMR scan indicating focal enlargement, akinetic
motion with aneurysm (arrow indicated) localized in the free
wall of right ventricular. Left: enhenced-CMR imaging; right:
non enhenced-CMR imaging.
(TFC) has been the frequently used method for the diag-
nosis of ARVC based on electrocardiographic, structural,
functional abnormalities and family history [2].
The patient firstly referred to our hospital with recur-
rent VT of LBBB morphology and an inferior axis, pre-
senting as an R wave in II, III and AVF leads; QS wave
in AVR and AVR leads with precordial R/S transition in
V4, which was typical features of idiopathic VT arising
from the RVOT. It is commonly believed that patients
with RVOT-VT rarely suffer from underlying structural
heart disease, and the prognosis is satisfactory. Because
of no abnormality detected by the first UCG screening,
the diagnosis of idiopathic RVOT-VT was made even
when ARVC was highly suspected in the presence of T
wave inversion in V1-V4 leads, which were characteris-
tic of ARVC. Because RVOT-VT can be adrenergically
mediated, β-receptor antagonist, metoprolol (25 mg,
twice daily), was orally administrated, however which
could not effectively prevent recurrence of VT. Some
studies have suggested that patients with ARVC could
manifest the same VT pattern as idiopathic RVOT-VT [3]
and T wave inversion (TWI) in V1-V3 of sinus rhythm,
which has a high sensitivity and specificity in the dis-
crimination of ARVC from RVOT [4]. Discrimination
between these 2 entities is critical due to different prog-
noses and therapeutic options. TWI in V1-V3 has been
reported in 36% to 96% of ARVC patients [5] and has
been proposed as a major criterion for the diagnosis of
ARVC [6].
UCG is commonly used as a screening tool for the di-
agnosis of ARVC, and most affected areas of RV involve
the apex, the outflow tract and posterior wall, which are
known as “triangle of dysplasia” and can be detected by
UCG. In this case, twice UCG scan revealed structural
and functional normal heart, leading to the misdiagnosis
of idiopathic RVOT-VT. Focal minor abnormality within
the right ventricle in the early stage of ARVC not de-
tected by UCG could be the major reason, which limited
the accuracy and utility of UCG. Compared with UCG,
Copyright © 2013 SciRes. OPEN ACCESS
X. M. Shi et al. / Case Rep orts in Clinical Med icine 2 (2013) 460-462
Copyright © 2013 SciRes. OPEN ACCESS
462
CMR has been proved to more precisely assess the re-
gional, morphological abnormalities and potentially the
presence of fatty infiltration. The patient referred to
CMR imaging and was found localized aneurysm and
dilation of the right ventricular free wall, which sup-
ported the diagnosis of ARVC. For patients with possible
ARVC who do not meet criteria of TFC, CMR may re-
veal the typical features and alter the subsequent treat-
ment [7,8]. It was reported that TWI of right precordial
leads usually occurred in patients with extensive right
ventricular involvement [9], however, the soldier has
pronounced TWI in the setting of minor abnormality,
which implies repolarization abnormality and may not be
parallel to anatomical changes.
ICD has been proved to be the most effective treat-
ment of ARVC by far. During the follow-up, we ob-
served that the soldier und erwent anti-tachycardia pacing
(ATP) and shock therapy of ICD in the setting of VT,
which successfully terminated tachyarrhymia and pre-
vented it from degenerating in to ventricular fibrillation.
REFERENCES
[1] Dimitrios, A., Nikos P, Angeliki, A., et al. (2011) Arrhy-
thmogenic right ventricular cardiomyopathy/dysplasia.
The Hellenic Journal of Cardiology, 52, 452-461
[2] McKenna, W.J., Thiene, G., Na va, A., et al., Task Force of
the Working Group Myocardial and Pericardial Dis- ease
of the European Society of Cardiology and of the Scien-
tific Council on Cardiomyopathies of the Interna- tional
Society and Federation of Cardiology (1994) Di- agnosis
of arrhythmogenic right ventricular dysplasia/ cardio-
myopathy. British Heart Journal, 71, 215-218.
http://dx.doi.org/10.1136/hrt.71.3.215
[3] O’Donnell, D., Cox, D., Bourke, J., et al. (2003) Clinical
and electrophysiological differences between patients
with arrhythmogenic right ventricular dysplasia and right
ventricular outflow tract tachycardia. European Heart
Journal, 24, 801-810.
http://dx.doi.org/10.1016/S0195-668X(02)00654-1
[4] Daniel, P., Morin, M., Andreas, C., et al. (2010) Useful-
ness of precordial T-Wave inversion to distinguish ar-
rhythmogenic right ventricular cardiomyopathy from
idiopathic ventricular tachycardia arising from the right
ventricular outflow tract. American Journal of Cardiology,
105, 1821-1824.
http://dx.doi.org/10.1016/j.amjcard.2010.01.365
[5] Nasir, K., Bomma, C., Tandri, H., et al. (2004) Electro-
cardiographic features of arrhythmogenic right ventricu-
lar dysplasia/cardiomyopathy according to disease sever-
ity: A need to broaden diagnostic criteria. Circulation,
110, 1527-1534.
http://dx.doi.org/10.1161/01.CIR.0000142293.60725.18
[6] Marcus, F., McKenna, W., Sherrill, D., et al. (2009) Di-
agnosis of arrhythmogenic right ventricular cardiomyo-
pathy/dysplasia (ARVC/D): Proposed modification of the
task force criteria. Circulation, in Pres s .
[7] Khang, L., Colin, E., Hamish, H., et al. (2012) Utility of
cardiac magnetic resonance in the evaluation of unse-
lected patients with possible arrhythmogenic right ven-
tricular cardiomyopathy. Clinical Medicine Insights: Car-
diology, 6, 153-162.
[8] Giovanni, Q., Syed, I., Andrew, S., et al. (2013) Arrhyth-
mogenic right ventricular cardiomyopathy mimics: role of
cardiovascular magnetic resonance. Journal of Cardio-
vascular Magnetic Resonance, 15, 16.
http://dx.doi.org/10.1186/1532-429X-15-16
[9] Nasir, K., Bomma, C., Tandri, H., et al. (2004) Electro-
cardiographic features of arrhythmogenic right ventricu-
lar dysplasia/cardiomyopathy according to disease se-
verity: A need to broaden diagnostic criteria. Circulation,
110, 1527-1534.
http://dx.doi.org/10.1161/01.CIR.0000142293.60725.18