What defines the PASS position for the device in LAAO?

In the context of Left Atrial Appendage Occlusion (LAAO), the PASS position describes the optimal placement of the device aimed at effectively occluding the left atrial appendage while minimizing complications and ensuring proper device function.

The defining characteristic of the PASS position is that the device is placed distal to or at the ostium of the left atrial appendage (LAA). This allows the device to remain securely in place, ensuring that it effectively blocks blood flow into the appendage where thrombus formation can lead to stroke risks. By being situated in this defined location, the device can more successfully prevent blood from re-entering the appendage, thereby reducing the risk of embolic events.

The other positioning options do not align with the PASS definition since being at the apex of the left ventricle doesn’t relate to LAA occlusion, and placement within the left atrium only or in contact with the interatrial septum does not confer the same effectiveness in occluding the LAA, which is the primary goal of the intervention.