[Myths and Legends: Electrocardiographic Position Control of Central Venous Catheters - Where Does the P Come from?]

Misplacement of central venous accesses can be associated with deleterious iatrogenic complications. Electrocardiography is often used to guide the placement of central venous catheters and to confirm the correct position of the catheter tip. A characteristically peaked p-wave is traditionally considered to indicate the entrance of the catheter tip into the right atrium. However, recent data show that intraarterial and even extravascular localisation might result in an increased amplitude. The peaked p-wave most likely detects the pericardial reflection rather than a right atrial catheter position, hence real-time ultrasound is to be recommended as a superior technique to confirm a correct catheter position.