Atheroma can be referred to as tiny fatty lumps which gets develop within blood vessels (arteries). These form as patchy areas of plaque and contribute to the hardening of arteries, a condition known as atherosclerosis.
Atheromas do not get developed instantly but instead it takes months or years to grow, becoming larger and thicker. With passage of time, a patch of atheroma can make an artery narrower, restricting and reducing the blood flow through vessel.
A danger that atheromas exhibit is their tendency to grow tiny cracks or rupture. When this happens, it can trigger the circulatory system to produce a blood clot (thrombosis) at the site of the atheroma. This can further lead to a complete obstruction of blood flow at the affected site, potentially causing a heart attack.
What are the causes of atheroma?
Atheromas are made up of mostly macrophage cells (a type of white blood cell) or debris, containing lipids (fats), calcium, and a variable amount of connective tissue. When these materials grow, they lead to the narrowing of the artery they are attached to.
Atheromas do not occur in veins, the blood vessels responsible for delivering de-oxygenated blood back to the heart, as they are not subjected to the same hemodynamic pressure that the arteries are.
The most important contributors to endothelial dysfunction or damage are hemodynamic disturbances (high blood pressure), hypercholesterolemia (high cholesterol levels), and inflammation.
Toxins that come from cigarettes, homocysteine, and wide-spectrum infectious agents can also contribute to atheroma development.
However, the exact origins of atheromatous plaque are not well understood. These fatty streaks can be found in the artery walls of infants but are usually absorbed. But in some of the cases, incomplete absorption can contribute to atheromatous plaque later in life.
Effects of Atheroma
Atheromatous plaque causes partial or complete obstruction of an artery. In the majority of cases, a clot formation is responsible for complete blockage.
Usually, the level of ischemic damage depends on the size of the artery involved and whether collateral circulation is present to help bypass the blocked artery.
Often the arteries of the heart, abdomen, and pelvis are affected by atheromatous plaque.
Complications associated with Atheroma
Atheromas and the narrowing or complete blockage of arteries can lead to several complications.
When the fibrous cap covering plaque tears down platelets that are involved in blood clot formation gets activated. When enough platelets reach the site of the plaque, blood clots form, causing ischemia and infarction.
Moreover, if atheromatous plaque gets calcified, it makes the artery brittle, rigid, and unresponsive to increases in blood pressure. This can result in a ruptured artery, leading to a hemorrhage or excessive bleeding.
Another complication can occur due to weakened arterial walls that are caused by plaque which has developed between layers of blood vessel tissue.
This may lead to an aneurysm, which is an enlargement of part of the artery, and there is a chance the artery could rupture.
Signs and symptoms of atheromas include:
- Angina (chest pain)
- Heart attack
- Transient ischemic attack (TIA)
- Peripheral vascular disorder
- Vascular dementia
- Pain in the calf
- Abdominal pain