What is a typical cause of air embolism during catheter procedures?

Air embolism during catheter procedures typically occurs when air enters the vascular system, often as a result of certain procedural techniques. Transseptal sheath manipulation is particularly prone to this risk because it involves puncturing through the interatrial septum, which can create pathways for air to potentially enter the heart and subsequently the bloodstream.

During this manipulation, if not done carefully or if the equipment is not appropriately primed, there's a risk of trapping air bubbles within the sheath or the manipulative instruments. These air bubbles can then enter the circulatory system, leading to an air embolism, which can cause serious complications.

In contrast, other factors such as excessive fluid infusion, blood clot dislodgement, and improper catheter positioning can lead to different complications but are not directly associated with the introduction of air into the system during the course of catheter manipulation. Excessive fluid could lead to fluid overload or interstitial edema, while blood clot dislodgement relates to thromboembolic events, and improper catheter positioning may result in incorrect delivery of therapy but does not generally introduce air into circulation. Therefore, the manipulation of transseptal sheaths specifically makes this procedure particularly associated with the risk of air embolism.