Open heart surgery is usually performed while the heart is still inside your body.
During coronary bypass surgery or open heart surgery, your breastbone is divided in half to expose your heart. Your heart is then connected to a heart-lung machine which completely takes over the function of your heart and lungs, permitting the surgeon to temporarily stop your heart.
With the heart now still and not moving, the surgeon then bypasses the blocked coronary arteries with a vein taken from your leg or arteries taken from your chest or arm.
Your heart is then allowed to resume beating, it is disconnected from the heart-lung machine, and your breastbone is closed with wires.
The operation of open heart surgery usually takes from three to five hours from start to completion.
In some cases, the surgeon may also be able to perform the operation while your heart is still beating which is called "off-pump" coronary bypass surgery.