Role of chest CT scan in atypical cardiac trauma management:
A 28-year-old man without previous medical history was brought to the emergency department of the hospital with worsening dyspnea, chest pain, and coughing developed following penetrating chest trauma by a nail gun which happened 5 hours earlier. He was repairing a sofa at his home using this gun when a nail was misfired to his chest accidentally. Upon primary survey, the patient's airway was intact, he was tachypneic, and had reduced lung sound at left hemithorax. He had a blood pressure of 110/70 mm Hg and a heart rate of 94 beats per minute and his heart sounds were muffled but regular S1-S2 were barely heard. He had a GCS score of 15/15. Upon chest inspection, a clean circular puncture wound was noted in the third intercostal space of the left hemithorax at the midclavicular line. According to the hemodynamic stability, he underwent a chest CT scan and it revealed a nail as a sharp hyperdense foreign body that penetrated the chest wall and passed through the lower lobe of the left lung and then entered the pericardium, and finally, the anterior aspect of the left ventricle (LV) reaching LV cavity. Also, patchy ground-glass opacities at the left lower lobe were noted which pertained to hemorrhage. Transthoracic echocardiography was performed and chest CT scan observation was confirmed and revealed pericardial effusion.

Considering clinical and imaging findings, the patient underwent midline sternotomy. After opening the pericardium, the gush of blood was completely evacuated and controlled by Teflon felt-supported suture, and to impede the left anterior descending artery involvement, Teflon-felt wrapping repair was performed in a horizontal mattress manner. After cardiac suturing, the nail was extracted from the left lung and the chest wall. Regarding surgery assessment, transesophageal echocardiography was done and confirmed no evidence of further intraventricular dissection, ventricular septal rupture, or any residual defect. There was no postoperative complication and he was extubated on postoperative day 2 and the drain output progressively diminished and was removed serially. The patient was discharged 4 days after admission. His outpatient follow-up, 2 weeks after surgery was uncomplicated.