Every open heart surgery presents the risk of complications.

The patient is closely monitored for these complications by staff and throughlab tests.

This is done for two reasons.

Three male surgeons in an operating room

Science Photo Library - Adam Gault / Getty Images

First, a pumping heart is a moving target, which makes surgery difficult or impossible for the surgeon.

If it is necessary to stop the heart, a cardiopulmonary bypass machinewill be used.

This oxygenates the blood and pumps it through the bloodstream when the heart and lungs cannot.

Procedures that require the bypass machine are often called on pump procedures.

Natarajan A, Samadian S, Clark S.Coronary artery bypass surgery in elderly people.Postgrad Med J.

2011;25(1):98-106. doi:10.1055/s-0031-1275176

National Heart, Lung and Blood Institute.Heart Surgery.