In IABP part 1 the cardiac cycle and cardiac output were reviewed. IABP part 2 reviewed the concepts of intra aortic balloon counter pulsation (inflation and deflation) and the relationship to the cardiac cycle. Part 3 focuses on the Teleflex AC3 Optimus IABP which is available from the Critical Care Unit. Note, the features on the AC3 are similar to the AC2 which is kept in the operating theatre.