The heart lung machine is used so that surgeons can operate on the arteries supplying heart muscle. These arteries may be diseased.
(a) Name these arteries and explain how they may become diseased.
(b) suggest why a patient is put on a heart lung machine during such an opperation.
(a) The arteries supplying the heart muscle are known as coronary arteries. There are two main coronary arteries: the left coronary artery, which further branches into the left anterior descending artery (LAD) and the circumflex artery, and the right coronary artery (RCA). These arteries may become diseased due to a condition called coronary artery disease (CAD).
Coronary artery disease occurs when the coronary arteries become narrowed or blocked by the buildup of fatty deposits, known as plaque, on the inner walls of the arteries. This process is called atherosclerosis. Risk factors such as smoking, high blood pressure, high cholesterol levels, diabetes, obesity, and a sedentary lifestyle can contribute to the development of CAD.
Over time, the plaque buildup can restrict or block the blood flow to the heart muscle. This decreased blood flow can lead to a lack of oxygen and nutrients reaching the heart, causing symptoms like chest pain (angina) or shortness of breath. In severe cases, a complete blockage of a coronary artery can result in a heart attack.
(b) During certain cardiac surgeries, such as bypass surgery or valve replacement surgeries, a patient may be put on a heart-lung machine, also known as a cardiopulmonary bypass machine. The heart-lung machine temporarily takes over the function of the heart and lungs, allowing the surgeon to operate on the heart while it is not beating and the patient's blood is being oxygenated outside of the body.
The purpose of using a heart-lung machine is to ensure the circulation of oxygenated blood to the body's organs and tissues while the heart is immobilized or stopped for the surgery. By diverting the blood away from the heart and lungs, the heart-lung machine allows the surgeon to operate on the arteries supplying the heart muscle without the risk of the heart beating and interfering with the precise surgical procedures.
During the surgery, the heart-lung machine collects deoxygenated blood from the patient, removes carbon dioxide, adds oxygen, and pumps the oxygenated blood back into the patient's body, providing adequate circulation and oxygenation to vital organs until the surgery is complete, and the heart can resume its normal function.