Coronary heart disease

Also known as ischaemic heart disease (IHD)

Coronary artery disease (CAD) is the most common type of heart disease and happens when the arteries that supply blood to the heart muscle (the coronary arteries) become hardened and narrowed. A gradual blockage can result in angina. A sudden or severe blockage can cause a heart attack or cardiac arrest.

Key points

  1. Coronary heart disease and stroke remain the number one causes of death and disability in many developed countries including New Zealand.
  2. One in 20 adults have been diagnosed with heart disease. That's more than 165,000 New Zealand adults.
  3. Every 90 minutes a New Zealander dies from heart disease. Many of these deaths are premature (the person dies too early) and could be prevented. 
  4. There are a number of steps you can take to reduce your risk, including being smokefree, being physically active, eating heart healthy foods, keeping to a healthy weight and having your blood pressure and cholesterol checked. 
  5. If you are 35 or older, check at what age you should start having a heart check.

What are the causes of coronary heart disease?

The narrowing of the coronary arteries can be due to the buildup of cholesterol and other material, called plaque, on their inner walls. This buildup is called atherosclerosis. As it grows, less blood can flow through the arteries. As a result, the heart muscle can't get the blood or oxygen it needs. This can lead to angina (chest pain) or a heart attack.

Most heart attacks happen when a blood clot suddenly cuts off the hearts' blood supply, causing permanent heart damage. Over time, CAD can also weaken the heart muscle and contribute to heart failure and arrhythmias.

  • Heart failure means the heart can't pump blood well to the rest of the body.
  • Arrhythmias are changes in the normal beating rhythm of the heart.


  1. National Heart, Lung, and Blood Institute, USA