Outcomes from patients in the New Zealand Cardiac Inherited disease registry have contributed to a significant piece of research regarding the use of ICDs (implantable defibrillators) in patients with CPVT (paper linked below).
Patients tended to do worse with an ICD. It is important to note that this does not mean that ICDs should never be implanted in people with CPVT. At least one of our subjects in New Zealand has had appropriate shocks despite being on full therapy , including flecainide. The key message from this work is that, whether patients with CPVT have an ICD or not, institution of at least double therapy is required for those who present with a cardiac arrest due to CPVT (beta blockers and flecainide), and close clinical follow up with repeat exercise testing on therapy is required. And of course, the diagnosis of CPVT must be a certain one; this result does not apply to people with other conditions such as HCM or long QT syndrome.