OBJECTIVE To evaluate cardiac function at the early phase of severe trauma. METHODS Prospective, clinical study. METHODS Anesthesiological Intensive Care Unit. METHODS 7 consecutive patients admitted after severe trauma (ISS: 38 +/- 9, mean +/- SD), without preexisting cardiac disease. METHODS Each patient received midazolam and sufentanyl for sedation. Right heart catheterization (Swan-Ganz) and transesophageal echocardiography (TEE) were performed. The fractional area change (FAC) of the left ventricle was calculated within 6 h following trauma and at day 1 and day 2 in order to evaluate left ventricular function. RESULTS All of the patients had a low FAC value < 50% at day 0 (43.2 +/- 2.4%, range 39-46%), which increased significantly at day 2 (52.5 +/- 4%, range 47-59%, p = 0.001), whereas heart rate and preload (assessed by left ventricular end diastolic area and pulmonary arterial occlusion pressure) were constant and afterload, assessed by systolic blood pressure, increased significantly between day 0 and day 2 (112 +/- 21 to 145 +/- 24 mmHg, p = 0.02). CONCLUSIONS The initial phase of severe trauma is associated with an abnormal cardiac function, suggested by a low FAC value. This myocardial dysfunction must be taken into account for early resuscitation after severe injury.