The earliest surgery on the heart took place in the 19th century, and involved surgical repair of the area around the heart. Surgery on the heart itself was limited by the fact that the heart must beat continuously in order to supply blood to the brain and vital organs. Surgeons needed to find a way to keep the heart motionless and emptied of blood before attempting repair, and were unable to perform surgery on the heart until this problem was solved.
Surgeons began to experiment with techniques that allowed the heart to stop beating while an operation was completed. First, heart surgeons had to find a way to provide blood to the rest of the body while the operation was completed. This is known as cardiopulmonary bypass, where an external system does the work of the heart and lungs. The first attempts started in the 1950’s, and used a patient’s family member to provide blood during the operation. This was soon replaced with the heart-lung machine, which did the work of oxygenating blood and pumping it to the body during surgery.
The second major hurdle was to find a way to slow the heart down while the operation was completed. This was completed with a combination of medications, potassium, and cold temperatures known as cardioplegia. After refinements in cardiopulmonary bypass and cardioplegia, heart surgeons began to develop techniques to surgically correct problems with the heart valves, coronary arteries, and structure of the heart.
Modern heart surgery has undergone tremendous advances in the last 25 years, and continues to advance with new techniques such as robotic heart surgery, transcatheter aortic valve surgery, endovascular aortic replacement.