The document discusses the principles of intra-aortic balloon pump counterpulsation. It provides a brief history of IABP development and use. It describes the hemodynamic effects of IABP including reducing systolic pressure and increasing diastolic pressure in the aorta and left ventricle. It lists common indications and contraindications for IABP use as well as potential complications. It also outlines the technique for IABP insertion and operation.