Trans-septal left atrial catheterisation.

A newly designed 4 FG double-lumen catheter with the second port located either 5 or 7 cm proximal to the tip was tested in five children undergoing open heart surgery. The catheter was inserted percutaneously and initially positioned in the superior vena cava, right atrium or inferior vena cava. During cardiopulmonary bypass, the tip of the catheter was repositioned manually in the left atrium across the interatrial septum. In all patients, left atrial pressure was monitored successfully while central venous pressure was monitored with the second port positioned in the superior vena cava. Removal of the catheter from the left atrium was easily performed and caused no problems.