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Problems with the heart's electrical system, called arrhythmias, can make it hard for the heart to pump blood efficiently.
Atrial fibrillation (AF) is an irregular and often rapid heart rate that commonly causes poor blood flow to your body. Although AF itself usually isn't life-threatening, it is a serious medical condition.
Electrical signals fire from multiple locations in the atria, causing abnormal quivering of the atria (1). The atrioventricular node — your heart's natural pacemaker — is unable to prevent all of these chaotic signals from entering the ventricles (2). Your ventricles respond to these extra, chaotic signals by beating faster than normal (3).
Please take a look at this animation for more information:
AF occurs when rapid, disorganized electrical signals cause the two upper chambers of the heart, to fibrillate. The term "fibrillate" means to contract very fast and irregularly. In AF, blood pools in the atria and isn't pumped completely into the ventricles, the heart's two lower chambers. As a result, the heart's upper and lower chambers don't work together as they should.
Often, people who have AF may not feel symptoms. However, even when not noticed, AF can increase the risk of stroke. In some people, AF can cause chest pain or heart failure, particularly when the heart rhythm is very rapid.
AF may occur rarely or every now and then, or it may become a persistent or permanent heart rhythm lasting for years.
The most common rhythm complication after coronary artery bypass graft surgery (CABG) is probably the occurrence of Atrial fibrillation (AF). Function is affected by the presence of AF, particularly if there has been damage to your heart . Affected patients may also be at increased risk for stroke. In addition, AF may cause significant symptoms of discomfort.
For many people with AFib, the disease symptoms can be very scary. People often say that when they have an episode of AFib, they feel as though a fish is flopping around in their chest, or that their heart feels like it will explode. Common symptoms include:
- Pounding or fluttering in the chest (palpitations)
- Shortness of breath
- Chest pain
- Dizziness or fainting
These symptoms may occur either once in a while, or all of the time. They can range from mild to severe. When symptoms become especially severe, many patients end up in the emergency room or hospitalized. However, 30 percent of people with AFib do not feel any symptoms at all.
AF is probably related to the combination of a number of factors.They include
- advancing age,
- underlying heart disease,
- Emphysema (COPD),
- Excessive alcohol and caffeine usage
- Atrial fibrillation occurs in up to 60 percent of binge drinkers with or without an underlying alcoholic heart disease. Most cases occur during and following weekends or holidays when alcohol intake is increased, a phenomenon that has been called "the holiday heart syndrome." Chronic heavy alcohol use does increase the risk of AF.
- There is a widespread belief that caffeine, particularly at high doses, is associated with palpitations and a number of arrhythmias, including AF.
- low blood counts of Potassium and Calcium after surgery.
AFib can be diagnosed through a simple test called an electrocardiogram (ECG or EKG), which creates a graph of the heartbeat. In people with AFib, this graph will show a chaotic, irregular line instead of the steady pattern seen in people with a normal heart rhythm:
Generally, the goals of treating atrial fibrillation are to:
- Reset the rhythm or control the rate
- Prevent blood clots that may cause a stroke or other complication
Treatment includes the use of Beta blocker medication and correct low Potassium and Calcium blood levels.If persistent for more than a few days, a blood thinner may become necessary to protect against the risk of thrombus (clot) formation, that can cause a stroke.
Usually all new onset AF should be managed with a blood thinner such as Warfarin (Coumadin) to protect against blood clots that may cause a stroke, Pulmonary embolus (PE), or a clot to other parts of your body. Atrial fibrillation, especially if not controlled, may also cause heart failure.
In some cases patients with otherwise normal heart function can be managed with aspirin alone to prevent complications such as a stroke. An algorithm such as the CHA2DS2-VASc score can estimate the risk of stroke and indicate whehter a patient should be treated with full anticoagulation.
Fish and fish oil supplements
Some data suggest that dietary fish intake or fish oil supplements, may reduce the incidence of arrhythmias.
The best treatment will depend on how long atrial fibrillation has been present, how bothersome the symptoms are and what the underlying cause is. If the symptoms are bothersome or if it is a new episode of atrial fibrillation, cardioversion may be needed:
- Cardioversion with drugs. This form of cardioversion uses medications called anti-arrhythmics to help restore normal sinus rhythm. This is often done in the hospital with continuous monitoring of your heart rate. If your heart rhythm returns to normal, your doctor often will prescribe the same anti-arrhythmic or a similar one to try to prevent more spells of atrial fibrillation.
- Electrical cardioversion. In this procedure, an electrical shock is delivered to your heart through paddles or patches placed on your chest. The shock stops your heart's electrical activity momentarily. When your heart begins again, the hope is that it resumes its normal rhythm.
Before cardioversion, a blood thinner such as warfarin (Coumadin) is usually given for several weeks to reduce the risk of blood clots and stroke.
- Maintaining a normal heart rhythm:
- Amiodarone (Cordarone, Pacerone)
- Dronedarone (Multaq)
- Propafenone (Rythmol)
- Sotalol (Betapace)
- Dofetilide (Tikosyn)
- Flecainide (Tambocor)
- Heart rate control drugs:
- Calcium channel blockers
- Calcium Channel Blockers like Diltiazem may provide better rate control and arrhythmia-related symptom relief than beta blockers in patients with permanent atrial fibrillation . A study has suggested that calcium channel blockers performed better than beta blockers on heart rate and arrhythmia-related symptoms in patients with permanent, rapidly conducted AF. and should be considered more often for rate control in patients with AF.
- Beta blockers
- Angiotensin-converting enzyme (ACE) inhibitors
- Other procedures:
- Cardioversion uses electric shock treatments or medicines to restore your heart back to a normal rhythm
- Surgical Maze procedures
- Preventing blood clots with blood thinners:
- Warfarin (Coumadin). Coumadin is a powerful medication that can have dangerous side effects. You'll need to have regular blood tests to monitor whether you take too much or too little Coumadin.
- Dabigatran (Pradaxa). Dabigatran is as effective as warfarin at preventing blood clots that can lead to strokes but doesn't require special blood tests
There are some things can be done to try to prevent recurrent spells of atrial fibrillation, such as reduce or eliminate caffeinated and alcoholic beverages from your diet, because they can sometimes trigger an episode of atrial fibrillation.
(From: Atrial fibrillation, http://www.mayoclinic.com/health/atrial-fibrillation/DS00291)