Stephen P Hoole, Duncan C McNab, Bushra S Rana, William R Davies and Leonard M Shapiro
Cobra head configuration of the Amplatzer Septal Occluder (ASO) is a benign but potentially avoidable phenomenon, occurring in approximately 3% of implantations. The mechanism of deformation is thought to occur due to device rotation and twisting of the ASO nytinol wires either in the delivery catheter or following interaction with adjacent heart structures e.g. left atrial wall after delivery.