Percutaneous access allows implementation of mechanical support in minutes, rather than hours, as is the case with more invasive systems. The TandemHeart Cannula Set  - EF is designed to accommodate various patient sizes and to permit appropriate flows at various pump speeds.

Following standard transseptal puncture and hole dilation using a two-stage dilator, the TandemHeart Transseptal Cannula - Extended Flow (THTC-EF) is advanced through the femoral vein into the left atrium.

The curved design at the distal end of the cannula body facilitates optimal placement of the tip in the left atrium. Centimeter markings at the proximal end of the cannula are used to record the location of the cannula at placement, and also serve as a visual aid for monitoring any change in location, which could occur when the patient is moved. Distal tip and side holes are configured to allow adequate blood flow and drainage of the left atrium.  Radiopaque disks are located in the tip of the transseptal cannula, for visualization under fluourscopy.

The obturator has a short, tapered tip for ease of insertion. A standard locking Luer connector at the proximal end of the obturator allows attachment of a hemostasis valve for dye injection, pressure measurement or blood sampling. Commercially available wire-reinforced arterial cannulae are used to return the blood into the patient's systemic circulation by way of the femoral arterial system. .