Atrial fibrillation, or AFib, is a heart condition causing an irregular rhythm. There are two different types of atrial fibrillation: valvular and nonvalvular.
Prior to treating you for atrial fibrillation, your doctor will consider the type you have, as the course of treatment varies. Nonvalvular atrial fibrillation is characterised by a patient who has either a prosthetic heart valve, or a heart valve disorder, but their atrial fibrillation is caused by something else, such as stress or high blood pressure.
Between 4 and 30 percent of those with atrial fibrillation are believed to have valvular atrial fibrillation, however there is disagreement over the exact definition of the valvular form. This extremely wide range in estimates is a result of the inability to agree on a clear distinction between which causes of atrial fibrillation should be considered valvular.
It's possible to experience no symptoms of atrial fibrillation. The condition can go undiagnosed for years, only being discovered during a physical examination, or in the event you require an electrocardiogram (EKG).
That being said, atrial fibrillation can present many symptoms.
It's possible that your condition may be intermittent, with you experiencing phases as you go in and out of atrial fibrillation. This is called paroxysmal atrial fibrillation. If your atrial fibrillation lasts for longer than a 12 month period it is considered to be persistent atrial fibrillation.
While there is not yet a standard and widely accepted definition for valvular atrial fibrillation, there are some causes that are generally accepted.
Mitral valve stenosis occurs when your mitral valve isn't as wide as it should be. When your mitral valve (the valve connecting your heart's left atrium and left ventricle) is too narrow, your blood flow to your left ventricle is irregular, causing your heart to beat irregularly.
The most frequent cause of mitral valve stenosis is rheumatic fever, a condition that is no longer common among the population of the United States, though it does still occur elsewhere in the world, especially throughout developing countries.
Another common cause of valvular atrial fibrillation is the use of artificial heart valves. These are used as replacements when your natural heart valves are diseased, damaged, or scarred.
The valve is comprised of a mechanical heart valve along with valve tissue from both a human and animal donor.
If you are not experiencing symptoms of atrial fibrillation your doctor could still discover the condition during the course of examining you for other reasons.
If a doctor suspects you have atrial fibrillation, they will physically examine you, and consider your medical and family history, before carrying out further tests. These will include an EKG, as well as an echocardiogram, chest X-ray, stress echocardiography, and blood tests.
There are several treatments your doctor may choose to use to control the rhythm and rate of your heartbeat, and prevent the formation of blood clots.
Anticoagulation medication is helpful in reducing the possibility of blood clots. If you have had an artificial heart valve fitted, anticoagulant medication will be vital to ensuring clots don't form on the flaps of your artificial valve.
Common forms of anticoagulants include vitamin K antagonists, like Coumadin (warfarin), which block the use of vitamin K throughout your body. Vitamin K is required to form a blood clot.
There are new alternative anticoagulants, like Xarelto (rivaroxaban) and Pradaxa (dabigatran), however, these aren't suitable for patients with valvular atrial fibrillation, particularly if they have a mechanical heart valve.
It's possible to reset a patient's heart rhythm using a procedure called cardioversion, which delivers an electric shock directly to your heart, effectively resetting the electrical activity within.
Medications like Tikosyn (dofetilide), Rythmol (propafenone), and Betapace (sotalol) can also be used to maintain the rhythm of your heart. Beyond medication, there are more invasive treatments, like the use of a catheter ablation, which can successfully restore your heart’s rhythm.
Your doctor will look at your overall health before recommending ablation and will usually begin by using anticoagulants in the first instance.
If you have an artificial heart valve or mitral valve stenosis you are at a higher risk for blood clots. Atrial fibrillation makes the risk of blood clotting even higher, and those with valvular atrial fibrillation are at an even higher risk of blood clots than those with nonvalvular heart disease.
It's important to properly manage the condition using anticoagulants, as well as interventions that will control your heart rate, as this will help reduce the risk of clots, stroke, and heart attack.