Congenital ventricular diverticulum presenting as sustained monomorphic ventricular tachycardia

Congenital ventricular diverticulum is a rare congenital cardiac defect. Most patients with this abnormality will remain asymptomatic and without complications during long-term follow-up. However a subgroup of these patients may experience life threatening complications such as ventricular arrhythmias, systemic embolism, sudden death, spontaneous rupture, and valvular regurgitation. We present a case of a patient with a congenital ventricular diverticulum presenting with sustained monomorphic ventricular tachycardia and evaluated by 64-slice CT. This is an uncommon but possibly life threatening arrhythmia described in less than 10 cases in the medical literature. The natural history of such patients as well as the appropriate treatment is unclear. Most of the literature advocates early surgical intervention. We decided to provide the patient with an implantable cardioverter defibrillator (ICD) and not surgical intervention due to the close proximity of the defect to the mitral valve.