A 27 year old man was admitted to hospital having taken an overdose of diazepam. He was managed conservatively and admitted for overnight observation and psychiatric assessment. He had a past history of substance abuse and was a registered methadone user.

The following day, unhappy at the treatment that he was receiving, the patient picked up a safety pin that was located by the side of his bed. He proceeded to straighten out the pin to a length of 9 cm and stab himself in the chest (upper panel). It was apparent to the medical team that the pin was moving in time with the heart beat of the patient. There was no haemodynamic compromise.

Transthoracic echocardiography showed that the pin had breached the pericardium and pierced the heart at the apex of the right ventricle, with the tip lodged in the apical segment of the interventricular septum (lower panel: LV, left ventricle; RV, right ventricle). A 1.3 cm rim of pericardial fluid was also evident. The pin was successfully removed by the cardiothoracic team. Repeat echocardiography showed that the pericardial effusion had not increased in size. The patient was observed on the cardiothoracic unit for 24 hours and then transferred to the psychiatric unit.

Cardiac tamponade is often a fatal complication of penetrating mediastinal injury. In some patients, the classically described triad (muffled heart sounds, distended neck veins, and hypotension) is often absent because of concurrent hypovolaemia. The diagnostic procedure of choice is transthoracic echocardiography as chest radiography is often normal.