The case of a 45-year-old man with severe tricuspid insufficiency and interatrial septum rupture caused by a car accident is described. The patient had a rupture of the anterior papillary muscle of the tricuspid valve and right-to-left shunt through an interatrial defect with severe hypoxemia that was difficult to distinguish from that caused by pulmonary damage. Transesophageal echocardiography was extremely useful for early diagnosis.