Understanding Heart Disease
WHAT IS HEART DISEASE?
Heart disease is a result of plaque buildup in your coronary arteries – a condition called atherosclerosis – that leads to blockages. The arteries, which start out smooth and elastic, become narrow and rigid, restricting blood flow to the heart. The heart becomes starved of oxygen and the vital nutrients it needs to pump properly.
HOW DOES HEART DISEASE DEVELOP?
From a young age, cholesterol-laden plaque can start to deposit in the blood vessel walls. As you get older, the plaque burden builds up, inflaming the blood vessel walls and raising the risk of blood clots and heart attack. The plaques release chemicals that promote healing but make the inner walls of the blood vessel sticky. Then, other substances, such as inflammatory cells, lipoproteins and calcium that travel in your bloodstream start sticking to the inside of the vessel walls.
Eventually, a narrowed coronary artery may develop new blood vessels that go around the blockage to get blood to the heart. However, during times of increased exertion or stress, the new arteries may not be able to supply enough oxygen-rich blood to the heart muscle.
In some cases, a blood clot may totally block the blood supply to the heart muscle, causing a heart attack. If a blood vessel to the brain is blocked, usually from a blood clot, it can cause an ischemic stroke. If a blood vessel within the brain bursts, it can cause a hemorrhagic stroke.
Cardiac ischemia occurs when plaque and fatty matter narrow the inside of an artery to a point where it cannot supply enough oxygen-rich blood to meet your heart's needs. Heart attack can occur - with or without chest pain and other symptoms.
Ischemia is most experienced during:
√ Exercise or exertion
√ Eating
√ Excitement or stress
√ Exposure to cold
Coronary artery disease can progress to a point where ischemia occurs even at rest. Ichemia can occur without any warning signs in anyone with heart disease, and it's more common in people with diabetes.