Truamatic dissection of the interventricular septum (IVS) is rare. The management scheme is not well-established.

A 15 year old girl sustained multiple injuries in a motor vehicle accident. Echocardiogram showed dissection of the posterointerior IVS, creating a 5.5x 4.5x 4 cc space communicating with the left ventricle through a 7mm defect. She remained stable and underwent elective repair at six months. On cardiopulmonary bypass the heart was arrested at 28 degrees and a right atriotomy made. An incision was made into the IVS, entering the cavity. On its leftward side, a 7mm defect was closed primarily. The cavity was obliterated by approximating the leftward to the rightward wall using sutures.

The patient was discharged on hospital day 4. Follow up echocardiogram at 7 months showed improved ventricular function and no recurrence of the cavity. Traumatic dissection of the IVS is rare. Patients must be observed carefully for progression to VSD, ventricular inlet or outlet obstruction, or free wall aneurysm, which can occur early or late. Elective repair, weeks to months after injury, is recommended if the initial lesion persists.