Implantable cardioverter-defibrillators (ICDs) improve the survival of patients with
ischemic or non-ischemic cardiomyopathy and a reduced ejection fraction.
However, the efficacy of ICD therapy in patients with right ventricular outflow
tract ventricular tachycardia (RVOT-VT) and early stage arrhythmogenic right ventricular dysplasia / cardiomyopathy (ARVD/C) has not been well clarified. Although
the prognosis of RVOT-VT is generally good, malignant forms of RVOT-VT resulting
in polymorphic VT have been reported by several investigators. Radiofrequency
catheter ablation is still effective in such patients, and thus an ICD
implantation is usually not required. On the other hand, according
to the current guideline in
patients with ARVD/C, an ICD
implantation is recommended for secondary prevention when the patients develop
sustained VT of VF. An ICD implantation may also be considered for primary
prevention in high-risk patients: extensive disease, family history of sudden
cardiac death, or undiagnosed syncope. Since an ICD implantation in the early stage of ARVD/C is
controversial, physicians should well consider its risks and benefit.
Early intervention with ICD therapy in ARVD/C patients may reduce the arrhythmic death but
increase the device related complications especially in younger patients.
Credits: Yoshiyasu Aizawa MD; Seiji Takatsuki MD; Keiichi Fukuda MD