What is atrial fibrillation? Why does one get it? How can it be prevented?
Atrial fibrillation is a condition in which the heart rhythm is irregular. Normally, the heart beats on an average 72 times a minute and has a very regular rhythm.
Each heartbeat normally starts in the upper right chamber of the heart from where an electric impulse travels to the lower chambers to complete the heartbeat. When there is disturbance in the initiation and/or transmission of the electrical impulse, the heartbeat goes haywire and irregular. This is called arrhythmia.
There are many types of arrhythmias affecting the upper and lower chambers of the heart. Atrial fibrillation is one of the common ones requiring treatment. It affects five percent of people older than 65 years. It accounts for up to 36 percent of all strokes in elderly people. The symptoms of atrial fibrillation are palpitation, shortness of breath, and fatigue.
Atrial fibrillation can be paroxysmal (episodic) or persistent. Some times the paroxysmal form occurs in healthy persons for no reason. It can also occur in individuals who develop acute infections, or in patients who have rheumatic heart disease, heart attack or have some other medical conditions.
Usually, paroxysmal attacks occur few times before permanent atrial fibrillation gets established. The episodic attacks may last from few seconds to few days. The onset and offset of atrial fibrillation can sometimes be quite abrupt. Permanent atrial fibrillation is almost always (with few exceptions) associated with some heart problem or other medical conditions like overactive thyroid gland.
The human heart beats 100,000 times each day. About 2000 gallons of blood is pumped out of the heart each day into the blood vessels. Irregular rhythm can impair this function. As a result, a person can go into heart failure, get a heart attack or stroke.
The most effective way to minimise the increased risk of stroke is to return the heart rhythm to sinus (regular) by electrical or chemical (medications) cardioversion. Cardioversion is a process by which the heart is returned to sinus rhythm. Cardioversion is safe, says an editorial in the British Medical Journal, with an estimated risk of stroke of less than one percent even among those at highest risk. If the atrial fibrillation has been present for more than 48 hours then the patient should receive blood thinners before and after the cardioversion to minimise the risk of stroke.
The editorial says that large series have shown initial success rates for cardioversion of around 75 to 91 percent of patients of all ages. It says that restoration and maintenance of sinus rhythm after successful cardioversion maybe enhanced by the use of medications, though optimal drug therapy has yet to be determined.
If it is difficult to sustain sinus rhythm, then the patient should receive blood thinners (like warfarin) on regular basis to reduce the risk of stroke by 70 percent. The editorial says that many physicians are reluctant to use blood thinners in the elderly due to associated risk of internal bleeding and prefer to keep them on aspirin. Aspirin does not do the job.
The editorial concludes by saying: In practice, even though the ideal may be unachievable, many elderly patents with atrial fibrillation remain suboptimally treated.
If you have irregular heart rhythm then get yourself checked out. If you think your condition is suboptimally treated then get a second opinion. It may save your life!
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