A 62-year-old woman developed shock immediately after the insertion of a right-sided chest tube. A chest roentgenogram showed the chest tube to be overlying the heart and possibly compressing the right ventricle. An animal model was developed to replicate this clinical situation. Using a domestic goat model pulmonary artery, peripheral arterial catheters were inserted along with a right sided chest tube placed to suction. A second chest tube guided by a flexible fiberoptic bronchoscope placed within its lumen was positioned between the right ventricle and the sternum of the animals. Thirteen paired measurements in three goats (average of 4.3 measurements per animal) of cardiac output, heart rate, and mean arterial blood pressure were made at baseline and after chest tube placement over the right ventricle. The data were analyzed using a paired t test statistic. Compared with baseline measurements, there was a significant decrease in cardiac output (p less than 0.001) and mean arterial pressure (p less than 0.001) as well as an increase in heart rate (p = 0.0056) after placement of the chest tube across the right ventricle. We conclude that a misplaced chest tube compressing the right ventricle can impede cardiac output and lead to a low cardiac output state. Physicians inserting chest tubes in patients should be aware of this potential complication as it is easily treated by withdrawal of the chest tube.