Fifty years old male patient with low ejection fraction (35%) was admitted to our department for elective bypass graft surgery. Anaesthesiologist decided to insert the pulmonary artery thermodilution catheter for hemodynamic monitoring. Insertion was normal. The only reported problem was not correct wedge pressure curve. After opening the pericardium we found perforation of the anterior wall of the right ventricle with approximately 8 cm of the catheter penetrated to the pericardial cavity. The perforation was sutured, operation was successfully completed and the patient had uncomplicated postoperative course. The only prevention of severe complication is strict observance of the implantation technique and recommendation given by manufacturers of all central venous devices. Pulmonary artery catheter is helpful, but might be a risky procedure.

        Key words: pulmonary catheter – thermodilution catheter – perforation of the right ventricle