Modern cardiac surgery requires many devices for diagnostic and therapeutic uses. Temporary pacemakers are external artificial conduction systems that are used for diagnostic purposes, management of rhythm disturbances that may occur immediately after separation of cardiopulmonary bypass, or prophylaxis postoperatively. Cardiogenic shock in the perioperative period has high in-hospital mortality, and short-term mechanical circulatory support devices are valuable in the management of this life-threatening condition. Postcardiotomy low cardiac output syndrome is a form of cardiogenic shock that occurs after cardiac surgery. For the management of this syndrome, the intra-aortic balloon pump, which provides internal counter pulsation to augment diastolic pressure and increase coronary circulation, with reduction in myocardial work, is a valuable assist. Extracorporeal membrane oxygenation can provide respiratory or cardiac output support or both. Miniature axial flow ventricular assist devices are newer technologies used for circulatory support of the postcardiotomy failing heart.