Conclusion.

A substantial proportion of adults under the age of 60 who present with ventricular tachyarrhythmia requiring an ICD will not have an apparent diagnosis after baseline ECG, TTE and coronary assessment. Comprehensive assessment with second-line investigations such as CMR, flecainide challenge and genetic testing may provide an underlying diagnosis in many of these patients, however the diagnostic evaluation in these patients is highly variable and often incomplete. Implementation of a systematic protocol for work-up of these patients requires further study.