A knot in the heart.

Few diagnostic modalities in medicine have been the subject of greater debate for as long after their inception as the pulmonary artery catheter. Placement of a Swan-Ganz catheter is associated with various complications, one of which is knotting. Complications of usage of these catheters are numerous and can have devastating effects. Knotting of Swan-Ganz catheters is a rare complication that can often be managed successfully using interventional radiological techniques. The case reported is a rare case of Swan-Ganz catheter knotting resulting from inserting an excessive length of Swan-Ganz catheter into the heart. Knotting can be prevented by following the principle rule in floating Swan-Ganz catheters by correlating the inserted length of pulmonary artery catheter (PAC) with the expected change in waveform.