2006 terni, corso di aggiornamento, la displasia aritmogena ventricolare

1. ““ Arrythmogenic RightArrythmogenic Right
Ventricular Cardiomyopathy ”Ventricular Cardiomyopathy ”
An Electrophysiologic Overview
Stefano Nardi, MD
AZIENDA OSPEDALIERA SANTA MARIA TERNIAZIENDA OSPEDALIERA SANTA MARIA TERNI
DIVISIONE DI CARDIOLOGIADIVISIONE DI CARDIOLOGIA
UNITA’ OPERATIVA DI ARITMOLOGIA CARDIACAUNITA’ OPERATIVA DI ARITMOLOGIA CARDIACA
LABORATORIO DI ELETTROFISIOLOGIA ED ELETTROSTIMOLAZIONELABORATORIO DI ELETTROFISIOLOGIA ED ELETTROSTIMOLAZIONE

2. Arrhythmogenic Right Ventricular Cardiomyopathy
Sudden Cardiac Death in
Children
• Primary electrical diseases
– Congenital Long QT Syndrome
– WPW with rapid antegrade conduction
• Cardiomyopathies
– Hypertrophic
– Dilated (idiopathic, post-chemo, etc.)
– Arrhythmogenic right ventricular
cardiomyopathy
• Structural abnormalities
– Anomalous coronary arteries
– Severe aortic stenosis

3. Arrhythmogenic Right Ventricular Cardiomyopathy
Background
•“ARVC” proposed in 1977 by Fontaine
•Occurs in teenagers and young adults
(>80% diagnosed by age 40)
–Rarely in early childhood
•Italian study – ARVC = 20% of
postmortem sudden deaths in patients <
35 years old
•Incidence 1:~5,000

4. Arrhythmogenic Right Ventricular Cardiomyopathy
Genetics
• Familial pattern in ~50%; Autosomal
Dominant
• Variable penetrance
• Multiple loci on chromosomes 14, 1,
10
• Requires thorough investigation of
family history, suspicious symptoms,
other unexplained sudden deaths

5. Arrhythmogenic Right Ventricular Cardiomyopathy
Family Tree
43
66
47
22
81
45 48
69
11 12 15
JRA
Cataracts
Syncope
1311
Adopted Lung CA Sudden death
Etiology?
VSD
Asthma
Hypothyroid Fibromyalgias
Bell’s palsy
Hypothyroid
45 51
1468
ARVC
Hypothyroid
OK OK OK OK
OK
Palps OK
OK
* *
*

6. Arrhythmogenic Right Ventricular Cardiomyopathy
Etiology?
• Degeneration
– Myocyte death due to inherited metabolic or
ultrastructural defect
– “Myocardial dystrophy”
• Inflammatory/infectious/myocarditis
– Coxsackie-like RNA found in some cases
• Apoptosis
– Programmed cell death
• Transdifferentiation
– From myocardial cells to adipose tissue

7. Arrhythmogenic Right Ventricular Cardiomyopathy
Presentation
• Variable and non-specific symptoms
– Palpitations
– Shortness of breath; CHF-like
symptoms
– Syncope
• Many present with sudden death
primarily

8. Arrhythmogenic Right Ventricular Cardiomyopathy
Natural history
• “Concealed” phase - subtle RV changes;
+/- minor ventricular arrhythmias; rarely
SD during competitive athletics
• “Overt electrical disorder” – overt RV
structural/functional changes;
symptomatic RV arrhythmias
• “Right heart failure” – global RV
dysfunction w/ preserved LV function
• “Biventricular pump failure” – signif LV
dysfunction

9. Arrhythmogenic Right Ventricular Cardiomyopathy
Physical Exam
• May be normal
• Extra-systoles
• Gallop rhythm, AV valve
insufficiency (systolic murmur)

10. Arrhythmogenic Right Ventricular Cardiomyopathy
ECG
• Abnormal in 90%, though non-specific
• T waves flattened, inverted (esp in V1-
V3)
• Right precordial QRS prolongation
• Epsilon waves (small amplitude potentials
at start of ST segment –
“intraventricular myocardial defect”)
• Signal averaging (SAECG)

11. Arrhythmogenic Right Ventricular Cardiomyopathy
Ventricular Arrhythmias
• May be associated with palps, presyncope,
and syncope
• Isolated PVC’s, sustained ventricular
tachycardia, or ventricular fibrillation leading
to sudden cardiac arrest
• Usually LBBB (suggesting right sided ectopy),
sometimes of multiple morphology
• Not specific for ARVC
– rule out congenital heart disease – repaired TOF,
Ebstein anomaly, etc.
– Idiopathic RVOT VT

12. Arrhythmogenic Right Ventricular Cardiomyopathy
Ventricular Arrhythmias
• Ventricular fibrillation in ARVC
– Incidence unclear
– Many cases discovered post-mortem
– Most likely mechanism of sudden death

13. Arrhythmogenic Right Ventricular Cardiomyopathy
Echocardiography
• Hypokinetic, dilated right ventricle
– Especially in RV outflow tract
• LV dilation if LV also involved

14. Arrhythmogenic Right Ventricular Cardiomyopathy
MRI
• The definitive test?
• Requires experienced cardiac
imaging specialist
• Can distinguish fat from muscle
• Cine MRI helps qualitate free wall
function

15. Arrhythmogenic Right Ventricular Cardiomyopathy
Cardiac Catheterization
• Right ventricular angiography
– Dilated, poorly contractile RV free
wall and RV outflow tract
• RV endomyocardial biopsy
– Excessive fatty infiltration
– Sporadic, typically involves epicardium
first (ie. False negative sampling)

16. Arrhythmogenic Right Ventricular Cardiomyopathy
Treatment
• Main objective is to prevent sudden
death
• Primary vs. secondary prevention
• Risk stratification
– Young age
– Competitive sports
– Malignant FHx
– Signif RV disease or LV involvement
– Syncope,
– VT/VF

17. Arrhythmogenic Right Ventricular Cardiomyopathy
Treatment
• Restricted activities
• Medic Alert bracelet/necklace
• Medications
– Amiodarone, sotalol, beta-blockers
• Catheter ablation
• Implantable cardioverter-
defibrillator (ICD)

18. Arrhythmogenic Right Ventricular Cardiomyopathy
Implantable
Cardioverter Defibrillator
Successful Induction; Self termination

19. Arrhythmogenic Right Ventricular Cardiomyopathy
Implantable
Cardioverter Defibrillator
Successful Induction and Defibrillation

20. Arrhythmogenic Right Ventricular Cardiomyopathy
Implantable
Cardioverter Defibrillator

21. Arrhythmogenic Right Ventricular Cardiomyopathy
Take Home Points
• Rare disorder, but increasing recognized
as cause of malignant ventricular
arrhythmias
• Sudden death can be initial presentation
• Consider in young pts with arrhythmias
or unexplained cardiomyopathy
• Management via suppression of
arrhythmias, AICD placement
• Families need support!!