A technique for unknotting an intracardiac flow-directed balloon catheter.

Described is an unusual complication occurring during right-sided cardiac catheterization using a 7F flow-directed balloon catheter. During an attempt to direct the catheter from the main pulmonary artery into the pulmonary wedge position, the tip became entangled in a loop of catheter and knotted. Initially, all attempts to unknot or remove the catheter failed. A movable core guide wire was passed through the major lumen of the catheter, resulting in the immediate unknotting of the catheter, thus allowing its withdrawal.