An x-ray in A-P projection shows the tip of the IABP (arrowhead) malpositioned in the aortic knob (arrow) near the origin of the left subclavian artery and well above the carina (asterisk). Image B shows the IABP (arrowhead) retracted to the level of the carina (asterisk), and at least 2 cm below the aortic knob (arrow).
