The blood from the operating field is sucked with the help of the cardiotomy sucker and pump, which is filtered to remove all particulate matter and then passed to the oxygenator for oxygenation. The oxygenated blood is pumped into the aorta via arterial filters where the particulate matter is filtered and air bubbles escape into the atmosphere.
Cardioplegia is discontinued after the desired time. After the cardiac surgery, the aortic cross clamp is released. As gradual re-warming is done, the heart starts beating. Temperature is brought to 37oC. In some cases, the surgeon may use direct internal defibrillation trying to revert the fibrillating heart to sinus rhythm. After the heart starts beating, CPB is discontinued after de-cannlation first aortic, then venous.