Although atrial fibrillation can feel weird and frightening, an “attack of AF” usually doesn’t have harmful consequences by itself. The real danger is the increased risk for stroke. Even when symptoms are not noticeable, AF can increase a person’s risks for stroke and related heart problems.
What causes atrial fibrillation?
Sometimes the cause of AF is unknown. Other times, it is the result of damage to the heart’s electrical system from other conditions, such as longstanding, uncontrolled high blood pressure or artery disease. AF is also the most common complication after heart surgery.
Usually, the most serious risk from AF is that it can lead to other medical problems, including:
- Heart failure
- Chronic fatigue
- Additional heart rhythm problems
- Inconsistent blood supply
How does AF lead to stroke?
- The heart quivers. The upper chambers (the atria) of the heart do not produce an effective, regular contraction.
- The contraction fails. Imagine wringing out a sponge. Without a good squeeze, water will still be left in the sponge. In the same way, when a heart contraction is either too fast or too uneven, it doesn’t completely squeeze the blood from the atria into the next chamber.
- Blood pools in the atria. Left over blood remains in the atria and may pool there.
- Risks of clotting go up. When blood has the opportunity to pool, it also has the opportunity to clot.
- Clots can travel and cause blockages. If a blood clot forms in the atria, it can be pumped out of the heart to the brain, blocking off the blood supply to an artery in the brain, causing a stroke. This type of stroke is called an embolic stroke or some doctors call it a cardioembolic stroke.
How does AF lead to heart failure?
Heart failure means the heart isn’t pumping enough blood to meet the body’s needs. AF can lead to heart failure because the heart is beating so fast that it never properly fills up with blood to pump out to the body.
As a result, when the heart can’t pump the blood forward, symptoms develop because:
Blood can “back up” in the pulmonary veins
(the vessels that return oxygen-rich blood from the lungs to the heart.) which can cause fluid to back up into the lungs.
When AF causes heart failure, fluid in the lungs can cause fatigue and shortness of breath.
Oxygen-rich blood is not being delivered to the body and brain, causing physical and mental fatigue and reduced stamina. Fluid also can build up in the feet, ankles, and legs, causing heart-failure related weight gain.
How does AF lead to additional heart rhythm problems?
The heart’s electrical system stops working properly, and fails to keep the heart chambers in rhythm.
Can AF simply go away?
Yes, rarely “spontaneous remission” does happen; it simply goes away. However, it is still something you and your healthcare provider will want to monitor because some people live with AF and do not feel the symptoms. However, the risks are still present.
Overall, most of the risks, symptoms and consequences of AF are related to how fast the heart is beating and how often rhythm disturbances occur.
AF may be brief, with symptoms that come and go. It is possible to have an atrial fibrillation episode that resolves on its own. Or, the condition may be persistent and require treatment. Sometimes AF is permanent, and medicines or other treatments can’t restore a normal heart rhythm.
But for all the reasons listed above, it is important to work with your healthcare provider to determine your treatment needs, and to understand your treatment options. It is also important to maintain a heart-healthy lifestyle and reduce your overall risks as much as possible.
Source: American Heart Association