Arrhythmogenic Right Venticular dysplasia (ARVD )
QxDx :
1. Hx : VT VF หรือ cardiac arrest
2. EKG : มี Epsilon waves ที่ V1-V3
3. Echo : พบ trabeculation in rt venticle

ARVD เป็น โรคผิดปกติไฟฟ้าหัวใจ ที่ทำให้เกิด VT VF เสียชีวิตได้

-ECG expression of this depolarization delay was first described in 1978
-Fontaine named tiny signals found during endocardial mapping (and also in the surface ECG) Right after the QRS complexes in leads V1-V3 Epsilon waves 

DDx of ARVD/C
-Cardiac sarcoidosis
-Idiopathic OTVT
-Some congenital heart disease with RV volume overload
-In case of LV involvement, any type of idiopathic NICM 

Incidence
-1:2,000 and 1:5,000
-4% of SCD cases referred for autopsy 10% of cases of “unexplained” cardiac arrest

-RV fibrofatty infiltration
-Potential risk for sudden cardiac death (SCD)
-Eight genes account for the majority of pathogenic
5 desmosomal genes (PKP2, DSP, DSG2, DSC2, and JUP)
3 nondesmosomal genes (TMEM43, DES, and PLN)
-50% to 60% - desmosomal

ARRHYTHMOGENIC SUBSTRATE
-Impaired gap junction function
-Reduction of the inward Na+ current (INa) in response to NaV1.5 dysfunction
-Dysregulation of intracellular calcium (Ca2+) handling
-structural abnormalities “triangle of dysplasia”
RV inflow tract
Outflow tract
Apex

Management
-Conservative treatment
-Pharmacologic therapy
-Implantable cardioverter defibrillators
-Ablation
-Cardiac transplantation
Conservative Treatment
-Restriction of exercise activity - 30 minutes of brisk walking per day
จำกัดห้ามออกกำลังกายหนัก ให้แค่เดินได้ 30 นาทีพอ
ลดการกระตุ้น
-Reduce the amount of VAs
-Reduce risk of heart failure
Pharmacologic therapy
Limited observational data for the use of antiarrhythmic therapy
B-blockers
- strongly recommend with ARVC and nonsustained VT Sotalol and amiodarone 

Implatable cardioverter-defibrillators
-History of resuscitated cardiac arrest
-Sustained VT (>100 beats/min, >30 seconds)
-Severe RV or LV dysfunction
-Device-related complications
3.9% annual rate of inappropriate shocks
4.2% annual rate of infection or lead malfunction

Ablation
Combined endocardial(ใส่สายผ่านจากเส้นเลือดเข้าห้องหัวใจ) and epicardial approach(ใส่สายจากด้านนอกหัวใจ ทำยากกว่า)
Epicardial ablation is generally required
ทำ Bipolat voltage mapping แล้วค่อยจี้

Cardiac transplatation
-Beneficial in patients with intractable Vas
-Favorable outcomes of transplantation when compared with patients with ischemic or restrictive cardiomyopathies

Conclusions
-Clinical phenotype caused by disordered function of the intercalated disk, particularly the desmosome, with resultant arrhythmogenesis
-Clinical, electrophysiological, and cardiac imaging parameters is important to both the diagnosis and risk

Ref.
Qcenter InterestingCase 6705