Atrial fibrillation Stroke
What is Atrial Fibrillation and Stroke?
Atrial fibrillation (AF) is defined as the rapid, irregular
beating of the left atrium (upper chamber) of the heart. These rapid contractions of the heart
are weaker than normal contractions, results in slow flow of blood in the atrium The blood
pools and becomes sluggish and can result in the formation of blood clots. When a clot leaves
the heart and travels to the brain, it can cause a stroke by blocking the flow of blood through
cerebral arteries. Some people with AF have no symptoms, but others will experience a
fluttering feeling in the area of the chest above the heart, chest pain, light headedness or
fainting, shortness of breath, and fatigue.
What Causes Atrial Fibrillation?
Atrial fibrillation can affect the structure of the heart that is why atrial fibrillation is
most common in older adults. Hypertension when untreated force the heart muscle to
work overtime in order to maintain normal blood flow through the body. This extra
work makes the heart muscle increase in size, known as cardiomegaly. As the size
of the heart increases, its muscle becomes stiff, and atrial fibrillation increases. Other
disorders that can lead to atrial fibrillation include
1)Heart valvular disorder (such as rheumatic heart disease),
2) Inflammation of pericardium (pericarditis)
3) Fluid around the heart (pericardial effusions),
4) Prior heart attacks, and
5) Diseases of the electrical conduction system of the heart
overproduction of thyroid hormones by the thyroid gland
(hyperthyroidism) can lead to atrial fibrillation, as several lung diseases and
infections, such as pneumonia.
Atrial fibrillation can also be caused by emotional or
physical stress, alcohol, nicotine, caffeine .
Why Atrial Fibrillation Cause Strokes?
Depend upon the age of a person, and the specific cause of chronic atrial fibrillation,
the incidence of stroke in people with this disorder can range from 5 to 17 times
higher than that of people without atrial fibrillation. Most commonly, atrial fibrillation
causes cardio embolic strokes -- those caused by a clot that escapes from the heart
and blocks a blood vessel in the brain. Blood clots are known to form when blood
remains clot for prolonged periods of time, or as a result of turbulent blood flow, both
of which are likely to occur disorganized heart beat of atrial fibrillation.