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Coronary Heart Disease - Causes - Causes

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There are three main types of coronary heart disease: obstructive coronary artery disease, nonobstructive coronary artery disease, and coronary microvascular disease. Coronary artery disease affects the large arteries on the surface of the heart. Many people have both obstructive and nonobstructive forms of this disease. Coronary microvascular disease affects the tiny arteries in the heart muscle.

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The cause depends on the type of coronary heart disease. The condition may also have more than one cause, including plaque buildup or problems that affect how the heart\u2019s blood vessels work. Visit How the Heart Works to learn more.

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\n Plaque buildup \n
- Coronary Heart Disease - Causes

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Plaque buildup in the arteries is called atherosclerosis. When this buildup happens in the heart's arteries over many years, the arteries become narrower and harden, reducing oxygen oxygen (OK-sih-jen):
A gas that is essential for humans and other animals to live. It is breathed into the lungs from the air. In the lungs, it enters the bloodstream, where red blood cells transport it to cells throughout your body. -rich blood flow to the heart. The result is coronary artery disease.

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\n \"Normal \n
\n Normal versus a blocked artery. The image shows a normal coronary artery with normal blood flow and a blocked coronary artery narrowed by plaque. The buildup of plaque limits the flow of oxygen-rich blood through the artery. Medical Illustration Copyright \u00a9 2019 Nucleus Medical Media, All rights reserved. \n
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Obstructive coronary artery disease means the heart\u2019s arteries are more than 50% blocked. The blood flow may eventually be completely blocked in one or more of the three large coronary arteries. In nonobstructive coronary artery disease, the large arteries may be narrowed by plaque, but not as much as they are in obstructive disease.

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Small plaques can also develop in the small blood vessels in the heart, causing coronary microvascular disease.

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\n Problems affecting the blood vessels \n
- Coronary Heart Disease - Causes

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Problems with how the heart\u2019s blood vessels work can cause coronary heart disease. For example, the blood vessels may not respond to signals that the heart needs more oxygen-rich blood. Normally, the blood vessels widen to allow more blood flow when a person is physically active or under stress. But if you have coronary heart disease, the size of these blood vessels may not change, or the blood vessels may even narrow.

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The cause of these problems is not fully clear. But it may involve:

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  • Damage or injury to the walls of the arteries or tiny blood vessels from chronic inflammation, high blood pressure, or diabetes.
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  • Molecular changes that are part of the normal aging process. Molecular changes affect the way gene gene (jeen):
    The unit that passes heredity from parents to children. Genes are pieces of DNA and contain information for making a specific protein.     and proteins protein (PRO-teen):
    Large molecule made up of building blocks called amino acids. Proteins make up the structure of a cell. Proteins are involved in structures, hormones, enzymes, muscle contraction, immune system responses, and other essential life functions. The amino acids involved are generally determined by a gene.     are controlled inside cells.
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In nonobstructive coronary artery disease, damage to the inner walls of the coronary arteries can cause them to spasm (suddenly tighten). This is called vasospasm. The spasm causes the arteries to narrow temporarily and blocks blood flow to the heart.

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\n \"Spasm \n
\n Spasm and plaque buildup can cause your arteries to narrow. Top left: image of a heart showing the coronary arteries. Top right: This artery does not have plaque buildup but has a vasospasm, causing it to narrow. This is a type of nonobstructive coronary artery disease. Bottom left: This artery is also classified as nonobstructive because it is less than 50% blocked by plaque. However, the vasospasm causes severe narrowing. Bottom right: This artery also has a spasm but is considered to be obstructive coronary artery disease, because it is 80% blocked. Medical Illustration Copyright \u00a9 2019 Nucleus Medical Media, All rights reserved. \n
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These problems can also happen in the tiny blood vessels in the heart, causing coronary microvascular disease (sometimes called coronary syndrome X). Coronary microvascular disease can happen with or without obstructive or nonobstructive coronary artery disease.

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\n \"Coronary \n
\n Coronary microvascular disease in small arteries and obstructive coronary artery disease in large arteries. Figure A shows the small coronary artery network, which includes a normal artery and an artery with coronary microvascular disease. Figure B shows a large coronary artery with plaque buildup. \n
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Learn more about the important role that inflammation, which is the body\u2019s reaction to an injury, plays in the development of coronary heart disease.

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\n Read more \n
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Plaque can attract platelets platelet (PLAYT-let):
A tiny piece of a cell that helps form blood clots to slow or stop bleeding and to help wounds heal; also known as a thrombocyte. and white blood cells to the area of buildup in the large coronary arteries, causing inflammation. Inflammation can also prevent the small arteries of the heart from responding to the physical, electrical, and chemical signals that tell the arteries when the heart needs more oxygen-rich blood. This can lead to coronary microvascular disease. Research suggests that inflammation may also reduce levels of HDL cholesterol (sometimes called \u201cgood\u201d cholesterol).

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Syndicated Content Details:
Source URL: https://www.nhlbi.nih.gov/subscribe/86289
Source Agency: National Heart, Lung, and Blood Institute (NHLBI)
Captured Date: 2019-01-22 15:53:00.0
","description":"There are three main types of coronary heart disease: obstructive coronary artery disease, nonobstructive coronary artery disease, and coronary microvascular disease. Coronary artery disease affects the large arteries on the surface of the heart. Many people have both obstructive and nonobstructive forms of this disease. Coronary microvascular disease affects the tiny arteries in the heart muscle.","id":18489,"mediaType":"Html","name":"Coronary Heart Disease - Causes","sourceUrl":"https://www.nhlbi.nih.gov/subscribe/86289"}]}