Medical References

Diseases & Conditions

Women's Health

Mental Health

Men's Health

Medical Web Links

MOL Site Map

Sites

Attention, chocolate lovers: You may not be able to help yourselves. Swiss and British scientists have linked the widespread love of chocolate to a chemical "signature" that may be programmed into our metabolic systems.
Read more health news

Brain Attack - Stroke from Cardiogenic Embolism

Overview, Causes, & Risk Factors

A stroke is the death of brain tissue that occurs when the brain does not get enough blood and oxygen. A stroke from cardiogenic embolism occurs when blood clots travel from the heart to an artery supplying the brain.

What is going on in the body?

A stroke from cardiogenic embolism is classified as an ischemic stroke, which means it is caused when the blood supply to the brain is interrupted. In this case, a blood clot is formed in the heart and travels through the bloodstream to block one of the arteries supplying the brain. The brain cells then die from lack of oxygen. The products released when cells die cause swelling in the brain. Since the skull doesn't allow much room for expansion, this swelling can damage the brain tissue even further.

What are the causes and risks of the condition?

A stroke from cardiogenic embolism is caused by a blood clot from the heart traveling to the blood vessels supplying the brain. Blood clots from the heart may be caused by an irregular heartbeat called atrial fibrillation, a condition in which the upper chambers of the heart beat very quickly and erratically. This irregular beating allows blood to pool and thus form clots within the heart.

A cardiogenic embolism may also be caused by severe congestive heart failure, a condition in which the weakened heart is unable to pump blood effectively. The sluggish blood flow through the heart allows clots to form.

Other conditions that increase the risk of a blood clot forming in the heart include infections of a heart valve and the presence of a surgically implanted artificial heart valve. Clots can also form when the heart muscle is damaged, as from a heart attack.

The person's risk of stroke from cardiogenic embolism is increased if other risk factors for stroke are also present.

The American Heart Association has recently issued guidelines for stroke prevention. The guidelines discuss risk factors for stroke in 3 categories: nonmodifiable, well-documented modifiable, and less well-documented or potentially modifiable.

The nonmodifiable factors are ones that cannot be changed by the individual, and include:

increasing age. A person's risk of stroke doubles each year after age 55.

race. Strokes occur approximately twice as often in blacks and Hispanics as they do in whites.

gender. Men have a 50% higher chance of stroke than women do.

family history of stroke or transient ischemic attack (TIA). A TIA is a short, reversible form of stroke that may serve as an early warning sign of stroke.

Well-documented modifiable risk factors are those that can be changed by the individual in conjunction with his or her healthcare provider. These factors are linked to stroke by strong research findings, and there is documented proof that changing the risk factor lowers a person's risk of stroke. These factors include:

high blood pressure

smoking

diabetes

asymptomatic carotid stenosis, or narrowing of one of the arteries in the neck

sickle cell anemia, a blood disorder that forms abnormal red blood cells

high cholesterol levels in the blood, including total cholesterol and LDL or "bad cholesterol." Low levels of HDL or "good cholesterol" are also cause for concern.

atrial fibrillation, an abnormal heart rhythm

Less well-documented or potentially modifiable risk factors for stroke are those that have less proof of either a link to stroke or the impact of modifying the risk factor. These factors include:

obesity

sedentary lifestyle

alcohol abuse

high blood levels of homocysteine, a blood component sometimes associated with a higher risk of stroke

drug abuse

blood disorders, such as blood that clots easily or deficiencies of various blood components

hormone replacement therapy (HRT). The AHA currently states that the risk of stroke associated with HRT appears low but needs further study.

use of birth control pills, or oral contraceptives

inflammatory processes, such as a chronic infection with chlamydia

Several recent studies have identified factors that seem to increase or decrease the risk of stroke in particular groups of people. These studies, which warrant further investigation, include these findings:

People who were treated for high blood pressure with thiazide diuretics, such as hydrochlorothiazide, had a significantly lower stroke risk than people on ACE inhibitors or calcium channel blockers.

Women ages 39 to 50 who ate more fish and omega-3 polyunsaturated fatty acids had a reduced risk of stroke. This was particularly true in women who did not take aspirin regularly.

Women ages 15 to 44 who had 2 drinks of wine a day had a 40% to 60% lower risk of stroke than women who did not drink alcohol.

Phenylpropanolamine, a compound contained in appetite suppressants and cold remedies, significantly increased the risk of hemorrhagic stroke in women 18 to 49 years of age. The Food and Drug Administration (FDA) has since asked manufacturers to remove phenylpropanolamine from their products.

In one study, people who were treated in emergency departments for transient ischemic attacks (TIA) had a 25% chance of having a stroke or other serious health event within the next 90 days.

Home • Sitemap • Contact Us • Advertising • Press Room • Give Us Your Feedback • Read Our Terms & Conditions and Our Disclaimer • Privacy Statement