Atrial fibrillation is a condition that disrupts your heartbeat. A glitch in the heart’s electrical system makes its upper chambers (the atria) beat so fast they quiver, or fibrillate. This causes the lower chambers (the ventricles) to beat out of sync.
AFib can be dangerous because it raises your risk of stroke and heart failure.
Not a Normal Heart Rhythm or Rate
Usually, the atria and ventricles work together so the heart pumps blood in a steady rhythm. But in AFib, they don't. The irregular beats can cause a fast, fluttering heart rate -- 100-175 beats per minute -- instead of the normal 60-100 beats per minute.
For many people, AFib doesn't cause obvious symptoms. But when there are, they'll often include:
- An uneven pulse
- A racing or pounding heart
- A feeling that your heart is fluttering
- Chest pain
- Feeling short of breath
- Lightheaded or dizziness
When your heart is in AFib, your blood doesn't move well throughout your body. You may feel:
- Dizzy or faint
- Weak and fatigued
When It's an Emergency
AFib isn't always a cause for alarm. But you should call 911 if you have:
- Severe chest pain
- Uneven pulse and feel faint
- Signs of a stroke, such as numbness or slurred speech
- And let your doctor know whenever something doesn't feel right.
Greater Risk of Stroke
When your heart isn't pumping as it should, the slow-moving blood can pool inside, which makes it easier for clots to form.
If that happens, and a clot travels through the bloodstream to your brain and gets stuck, you could have a stroke.
People with AFib are five times more likely to have one.