Download Arrhythmogenic right ventricular cardiomyopathy

Article
"Development of the European Network in Orphan Cardiovascular Diseases"
„Rozszerzenie Europejskiej Sieci Współpracy ds Sierocych Chorób Kardiologicznych”
Title:
Arrhythmogenic
right
ventricular
cardiomyopathy – still a diagnostic and therapeutic
challenge.
RCD code: III-4A
Author: Prof. Piotr Podolec, MD, PhD
Affiliation: Department of Cardiac and Vascular Diseases, John Paul II Hospital in Cracow,
Poland
Date:
BACKGROUND
Arrhythmogenic right ventricular cardiomyopathy (ARVC), previously known as
arrhythmogenic right ventricular dysplasia (ARVD) is a rare myocardial disease caused by
replacement of cardiomyocytes by fibrous and fatty tissue. This pathological process leads to
dilation of the right ventricle (RV), thinning of its wall, hemodynamic dysfunction and
electrical instability. Patients with ARVC usually complain of heart palpitations, dizziness,
and recurrent syncopes.
DISCUSSION
ARVC is regarded as a distinct morphological and functional cardiomyopathy, which
can be subclassified into familial (genetic) and nonfamilial types. The prevalence of ARVC is
estimated to be 1:5000/10 000 in the general adult population and it mostly affects men. It is
considered a frequent cause of otherwise unexplained sudden cardiac death (SCD) which in
John Paul II Hospital in Kraków
Jagiellonian University, Institute of Cardiology
80 Prądnicka Str., 31-202 Kraków;
tel. +48 (12) 614 33 99; 614 34 88; fax. +48 (12) 614 34 88
e-mail: [email protected]
www.crcd.eu
those patients is strongly related to exercise (e.g. in athletes). It is probably triggered by
increased exertional RV stress and high levels of catecholamines.
In at least half of the
reported cases, ARVC is found among members of a patient’s family and is typically
autosomal dominant with variable penetrance. The majority of causative mutations affect the
genes encoding desmosomal proteins, others concern genes for cardiac ryanodine receptor
and transforming growth factor‑β3. So far at least nine different genetic types of ARVC
have been distinguished. Fibro-fatty degeneration of RV myocardium is a reparative
mechanism for necrosis and apoptosis of myocytes. The regions affected are those prone to
increased hemodynamic stress (the so called “triangle of dysplasia” which includes the RV
inflow and outflow tracts and its apex).
A tendency to ventricular arrhythmias is best
explained by the micro- and macroreentry circuits that form in the borders between the
normal and altered ventricular wall.
The disease usually manifests itself in adolescence and early adulthood. The main
symptoms include heart palpitations, dizziness, syncope or even SCD. In most cases, ARVC
is a progressive disorder, often
consisting of three stages: (1) latent phase
(discrete
morphological changes, normal ECG, absent/asymptomatic arrhythmias); (2) electrical
instability phase
(regional RV wall motion abnormalities, symptomatic ventricular
arrhythmias); (3) dilation phase (RV dilation and failure). The 2010 ESC Task Force
algorithms encompass six categories such as: (1) dysfunction and structural alternations of
RV,
(2)
RV
wall
histology,
(3)
ECG
repolarization
abnormalities,
(4)
ECG
depolarization/conduction abnormalities, (5) arrhythmias, (6) family history. There are major
and minor criteria within each category. Diagnosis is made on the basis of following tests’
results: electrocardiogram, echocardiography, cardiac magnetic resonance imaging, RV
angiography, endomyocardial biopsy and electrophysiological study with electro-anatomic
mapping.
Due to evident association between SCD and exercise, persons diagnosed with ARVC
should not be engaged in any professional sports. The goal in the management of ARVC is to
prevent SCD. Several randomized controlled trials unequivocally confirmed benefits of
implantable cardioverter-defibrillator (ICD) in both primary and secondary SCD prevention
in those patients. Unfortunately ICD implantation complications may add up to those specific
John Paul II Hospital in Kraków
Jagiellonian University, Institute of Cardiology
80 Prądnicka Str., 31-202 Kraków;
tel. +48 (12) 614 33 99; 614 34 88; fax. +48 (12) 614 34 88
e-mail: [email protected]
www.crcd.eu
to ARVC, for instance resulting in perforation
of the thin RV wall. Moreover, progressive and extensive fibro-fatty myocardial degeneration
may compromise effectiveness of ICD interventions. Although antiarrhythmic medications
(sotalol, amiodarone), and radiofrequency (RF) ablation can decrease the number of
ventricular arrhythmias, these methods do not prevent SCD and therefore cannot be
considered an alternative to ICD but rather an adjunvant therapy.
Increasing awareness of ARVC and advancement in therapeutic methods (particularly
ICD application), have led to a substantial decrease in SCD statistics. However, severe RV
failure leading to death has been not unfrequently observed in the recent years.
CONCLUSION
Arrhythmogenic right ventricular cardiomyopathy is a rare but very dangerous entity
which may cause dangerous ventricular arrhythmias (including electrical storm) associated
with sudden cardiac death and right ventricular failure. It should always be suspected in
young, active adults with history of syncope and recurrent ventricular arrhythmias. There are
specific diagnostic algorithms for ARVC. Early diagnosis is crucial and ICD implantation
along with adjuvant therapy may prevent SCD and allow the patients to live a full normal life.
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John Paul II Hospital in Kraków
Jagiellonian University, Institute of Cardiology
80 Prądnicka Str., 31-202 Kraków;
tel. +48 (12) 614 33 99; 614 34 88; fax. +48 (12) 614 34 88
e-mail: [email protected]
www.crcd.eu
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John Paul II Hospital in Kraków
Jagiellonian University, Institute of Cardiology
80 Prądnicka Str., 31-202 Kraków;
tel. +48 (12) 614 33 99; 614 34 88; fax. +48 (12) 614 34 88
e-mail: [email protected]
www.crcd.eu
John Paul II Hospital in Kraków
Jagiellonian University, Institute of Cardiology
80 Prądnicka Str., 31-202 Kraków;
tel. +48 (12) 614 33 99; 614 34 88; fax. +48 (12) 614 34 88
e-mail: [email protected]
www.crcd.eu