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May 29, 2006
Atrial Fibrillation Treatment
by SirGan
 Atrial fibrillation is very common heart rhythm disorder which is caused by a rhythm disturbance of the atria that results in irregular, chaotic, ventricular waveforms varying from slow to extremely rapid heart beating. What happens during this condition? Well, during atrial fibrillation, the heart's two small upper chambers called the atria quiver instead of beating effectively. That’s why- blood isn't pumped completely out of them, so it may pool and clot. If a piece of a blood clot in the atria leaves the heart and becomes lodged in an artery in the brain, it can lead to a stroke.IncidenceAtrial fibrillation is the most common cardiac arrhythmia. More than 2 million Americans have this condition, which can cause palpitations, shortness of breath, fatigue and stroke. The condition is increasingly common with advancing age. It affects less than 1 percent of Americans younger than 60, but as many as one in 10 people older than 80. Overall, approximately 15-25% of all strokes in the United States can be attributed to atrial fibrillation.
Risk factorsKnown risk factors include:
Additional risk factors, such as advanced age and prior history of stroke, diabetes, and hypertension, place patients with preexisting atrial fibrillation at even higher risk for further complications such as stroke.
Signs and symptoms of atrial fibrillationIt is logical to assume that a heart in atrial fibrillation simply doesn't beat efficiently which means that it may not be able to pump an adequate amount of blood which leads to the drop of blood pressure!
Although some people with atrial fibrillation have no symptoms, other people experience:
Some people with atrial fibrillation have no symptoms and are unaware of their condition until their doctor discovers it during some regular physical examination.
Normal anatomy of the heart and mechanism of conditionHeart normally consists of four chambers, two upper chambers called atria and two lower chambers called ventricles. Within the upper right chamber there is a specific group of cells called the sinus node which represent a natural heart's pacemaker. The sinus node produces the impulse that starts each heartbeat. During a normal rhythm, the impulse travels first through the atria, then through a connecting pathway between the upper and lower chambers called the atrioventricular node.
What happens in atrial fibrillation? In atrial fibrillation, the atria are affected by chaotic electrical signals. As a result, normally- they quiver. Another result is that the ventricles also beat rapidly, but not as rapidly as the atria. This leads to the irregular and fast heart rhythm that affects both atria and ventricles. The heart rate in atrial fibrillation may range from 100 to 175 beats a minute. The normal range for a heart rate is 60 to 100 beats a minute.
Possible causes of atrial fibrillationThe most common cause of atrial fibrillation is defiantly some abnormality in the heart's structure. Many diseases that could affect the heart's valves or pumping system also are likely causes, as is long-term high blood pressure. However, some people who have atrial fibrillation don't have underlying heart disease, in which the cause is unknown.
Other possible causes of atrial fibrillation include:
Classification of atrial fibrillationsThe American Heart Association have proposed the following classification system based on simplicity and clinical relevance:
Any patient newly diagnosed with atrial fibrillation fits in this category, as the exact onset and chronicity of the disease is often uncertain.
Any patient with 2 or more identified episodes of atrial fibrillation is said to have recurrent atrial fibrillation. This is further classified into paroxysmal and persistent based on when the episode terminates without therapy.
Atrial fibrillation is said to be paroxysmal when it terminates spontaneously within 7 days, most commonly within 24 hours.
Persistent or chronic atrial fibrillation is atrial fibrillation established for more than seven days. Differentiation of paroxysmal from chronic or established atrial fibrillation is based on the history of recurrent episodes and the duration of the current episode of the condition.
Lone atrial fibrillation is defined as atrial fibrillation in the absence of clinical findings. Patients with this condition who are under 65 have the best prognosis.
Risk factorsThere are several risk factors that could be linked to atrial fibrillation and the most common are:
The older you are, the greater your risk of atrial fibrillation. As you age, the electrical and structural properties of the atria can change. This may lead to the breakdown of the normal atrial rhythm.
Anyone with heart disease faces an increased risk of atrial fibrillation.
It is proven that people with thyroid problems, diabetes and high blood pressure have an elevated risk of atrial fibrillation.
It is considered that obesity also may play an important role in the development of atrial fibrillation.
Diagnosis of atrial fibrillationElectrocardiogramAtrial fibrillation is best diagnosed with an electrocardiogram, an investigation performed routinely whenever irregular heart beat is suspected. Characteristic findings are:
Holter monitor testingThis is a portable version of an ECG which is being used to monitor patient’s heart activity for 24h! It's especially useful in diagnosing rhythm disturbances that occur at unpredictable times. Patient wears the monitor under clothing.
EchocardiogramThis is very good and effective diagnostic tool. In this test, sound waves are used to produce a video of patient’s heart. Sound waves are directed at heart from a wand-like device called transducer that's held on patient’s chest. The sound waves that bounce off patient’s heart are reflected back through your chest wall and processed electronically to provide video images of heart in motion.
Blood testsThese blood tests can help a doctor rule out thyroid problems or blood chemistry abnormalities that may lead to atrial fibrillation.
Possible complications of atrial fibrillationThere are two possible and very dangerous complications of atrial fibrillation! These are:
The fact is that the chaotic rhythm may cause blood to pool in your atria and form clots. These blood clots could dislodge from heart and travel to brain. There it might block blood flow, causing a stroke. A blood clot can also lodge in other blood vessels, such as those supplying the kidneys or legs.
Atrial fibrillation alone may weaken the heart, leading to heart failure.
Treatment of atrial fibrillationTreatments for atrial fibrillation include medications and procedures to regulate heart rhythm. The most important goals of treating atrial fibrillation include:
Restoring the heart to a normal rhythmIn order to correct atrial fibrillation doctors often perform a procedure called cardioversion which can be done on two ways:
Medications called anti-arrhythmics, which are designed to stop the atria's quivering and restore normal sinus rhythm, are commonly used medications. Some of the most common are: amiodarone (Cordarone, Pacerone), propafenone (Rythmol), procainamide (Procanbid), sotalol (Betapace) and dofetilide (Tikosyn).
In this short procedure an electrical shock is delivered to patient’s heart through patches placed on his or hers chest. The fact is that the shock stops heart's electrical activity for a split second. And when it begins again, it may resume normal rhythm.
Slowing the heart rateIn the situations when atrial fibrillation can't be converted, the goal is to slow the heart rate and in order to do that- doctors are prescribing the medication digoxin (Lanoxin). It can control heart rate at rest but not as well during activity.
Preventing blood clotsWhen someone is at especially high risk of stroke doctor may prescribe blood-thinning medications called anticoagulants, such as warfarin (Coumadin) or aspirin.
Non-drug treatment
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