In this study, the clinical and implantable cardioverter-defibrillator 
(ICD)-related follow-up of patients with catecholaminergic polymorphic 
ventricular tachycardia (CPVT) with homogenous missense mutations in CASQ2 was 
summarized. Patients were followed in a pediatric cardiology clinic and an ICD 
clinic. All patients were treated with high-dose β blockers. ICDs were 
recommended for patients who remained symptomatic despite medical treatment. 
Twenty-seven patients were followed for 1 to 15 years (median 9). Twenty 
patients (74%) were symptomatic at diagnosis; 13 (65%) remained symptomatic 
after treatment with high-dose β blockers and thus were advised to receive ICDs. 
Eight of these patients refused ICDs, and eventually 6 (75%) died suddenly. Four 
of the 5 patients who received ICDs had ventricular tachycardia storms treated 
but not terminated by recurrent ICD shocks. These ventricular tachycardia storms 
(2 episodes in 2 patients and 1 episode in 2 patient) terminated spontaneously 
after finishing the programmed ICD shocks, without degeneration to ventricular 
fibrillation. None of the patients who received ICDs died. In conclusion, 
patients with CASQ2-associated CPVT should be recommended to receive ICDs to 
prevent sudden death when medical therapy is not effective. These patients may 
have recurrent ventricular tachycardia storms treated but not terminated by 
recurrent ICD shocks, without degeneration to ventricular fibrillation.