In coronary heart disease layers of fatty material build up inside the coronary arteries and narrow them. This reduces the flow of blood through the coronary arteries, so the heart muscle gets too little oxygen. If an artery is blocked completely, part of the heart muscle can die in a heart attack. It is a non-communicable disease, so it cannot be passed from one person to another.
A stent is a small mesh tube placed inside a coronary artery to keep it open. It works straight away and recovery is quick, but it does not cure the disease, it needs an operation, and the artery can narrow again. Statins are drugs that reduce blood cholesterol, which slows down the rate at which fatty material is deposited. They reduce the risk of heart disease but must be taken for years, and some people get side effects.
Heart valves can become faulty. A valve may not open fully, or it may develop a leak, so blood does not flow efficiently and the body gets less oxygen. A faulty valve can be replaced with a biological valve, taken from an animal or a human donor, or with a mechanical valve. Mechanical valves last a long time but the patient needs drugs that prevent blood clotting. Biological valves do not need these drugs but may wear out sooner.
In heart failure, a donor heart, or a heart and lungs, can be transplanted. The risks are that a suitable donor must be found, and the immune system of the patient may reject the new organ, so they must take drugs to reduce this. An artificial heart is occasionally used to keep a patient alive while they wait for a transplant, or to let the heart rest so it can recover. Artificial hearts can cause blood clots and infections.
