Why AFib Matters

What are the consequences of atrial fibrillation (AFib)?


Although atrial fibrillation can feel weird and frightening, an “attack of AFib” usually doesn’t have harmful consequences by itself. The real danger is the increased risk for stroke. Even when symptoms are not noticeable, AFib can increase a person’s risks for stroke and related heart problems.

What causes atrial fibrillation?


Sometimes the cause of AFib 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. AFib is also the most common complication after heart surgery.

View an animation of atrialfibrillation.

Usually, the most serious risk from AFib is that it can lead to other medical problems, including:

  • Stroke
  • Heart failure
  • Chronic fatigue
  • Additional heart rhythm problems
  • Inconsistent blood supply


Learn about the important connection between atrial fibrillation, high blood pressure and stroke.

How does AFib 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. Leftover 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 AFib lead to heart failure?


Heart failure means the heart isn’t pumping enough blood to meet the body's needs. AFib 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 doesn't efficiently pump the blood forward with strong contractions, 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 AFib 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 AFib lead to additional heart rhythm problems?


Basic answer: The heart’s electrical system stops working properly, and fails to keep the heart chambers in rhythm.

Thorough answer: Every heartbeat is controlled by the heart’s electrical system. To understand why atrial fibrillation is a problem, it is helpful to understand the normal patterns of the heart’s electrical system.

View an animation of a normal heartbeat.

The heart’s normal electrical pattern:

  • The current travels from top to bottom. The heartbeat starts at the top of the heart and – like an electrical wave – the current travels to the lower parts of the heart, signaling the tissue to contract.
  • The sinoatrial (SA) node starts the contraction in the top of the heart. The right atrium (top section of the heart) houses a group of cells called the sino-atrial node. In healthy adults, the SA node fires off between 60-100 heartbeats per minute. The electrical wave moves through the atria to “gatekeeper node."
  • The atrioventricular (AV) node regulates the timing of the lower portion of the heart. The AV node serves as a "gatekeeper" for all of the electrical pulses going through the atria (top sections) to the ventricles (bottom sections). The electrical pulses are delayed at the AV node before they are allowed to move into the ventricles. The delay gives the ventricles extra time to finish filling with blood before contracting.
  • The ventricles contract and pump blood out to the lungs and the body.

Electrical problems in atrial fibrillation:

  • In AFib, the SA node may not start the contraction. Instead, the contraction might start randomly in other areas of the atria or even in the pulmonary veins.
  • In AFib, the electrical current doesn’t flow in an organized top-to-bottom fashion. Instead, contractions are rapid and disorganized.
  • In AFib, the AV node often can’t regulate the chaotic current. It does its best to protect the ventricle from extra electrical impulses, but it can’t stop all of them. As a consequence, the ventricle beats more often than it should – giving rise to the noticeable symptoms of breathlessness and fatigue.
  • When the beat is off, the blood supply can be unpredictable. So, even though the ventricles may be beating faster than normal, they aren't beating as fast as the atria. Thus, the atria and ventricles no longer beat in a coordinated way. This creates a fast and irregular heart rhythm. In AFib, the ventricles may beat 100 to 175 times a minute, in contrast to the normal rate of 60 to 100 beats a minute.


The amount of blood pumped out of the ventricles to the body is based on the randomness of the atrial beats.

The body may get rapid, small amounts of blood and occasional larger amounts of blood. The amount will depend on how much blood has flowed from the atria to the ventricles with each beat.

Can AFib 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 AFib and do not feel the symptoms. However, the risks are still present.

Overall, most of the risks, symptoms and consequences of AFib are related to how fast the heart is beating and how often rhythm disturbances occur.

AFib 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 AFib 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.

 

Recent Discussions From The Newly Diagnosed Forum
yollicsa avatar

I went to the ER at approx. 8:00 PM Friday, 7/13/18 with an odd feeling in my chest and a heart rate averaging 164 BPM up to 189, per my Polar HRM.  Diagnosed as being in AFib VERY quickly by ER staff.  I converted to sinus rhythm about 4.5 hrs later (12:30 AM) and then went back into AFib about 17 hours later for a short time.  I was released from the hospital around noon on Sunday and was sent home on Eliquis (5 mg, 2X) and Cardizem.  On Tuesday, my cardiologist deleted the Cardizem and put me on Sotalol (1/2 80 mg tablet, 2X).

I am 66 years old and am quite active.  I exercise regularly, play softball and, most importantly, played hockey 3 plus times a week in the winter.  I am VERY concerned about the impact AFib and the associated medications will have on my activity.  I know "contact sports" are not recommended for people on blood thinners but our hockey is mostly "old guy" hockey where checking is not permitted.  Unfortunately, contact is not totally unavoidable so I am looking for input on people's experiences in this area.  My cardiologist was clearly leary of me playing hockey but did not say "no."  The cardiologist in the hospital felt it wasn't a big problem given that is not highly competitive and I wear a helmet with a face mask.  Additionally, I have been talking to some of my leaguemates and already know of several that have been on blood thinners for some time.  All words of wisdom will be appreciated!

Thanks,

Steve

Lockhart07 avatar

When is a heart rate too fast? I was just sitting on the couch reading a book when suddenly I had shortness of breath. I check my Apple Watch and my heart rate was 98 bpm. But what’s too high? I’m on 50 mg of Metoprolol. 

SinusRhythm avatar

I have on and off AFib now for 6 months.  I converted with Sotalol (200mg) each dose.  Would not convert on 160mg so they bumped it up to 200mg.  Was in NSR for 4 days on Sotalol 200mg and then had a breakthrough atrial flutter 30 minutes after taking the Sotalol.  Pulse was in the 130's, 140's and I even saw 152. Thought it was a reaction to Sotalol.  The flutter lasted 3 hours.  12 hours later I took the next Sotalol 200mg dose.  Had another breakthrough atrial flutter 30 minutes after the dose.  Lasted 3 hours.  Went to the ER.  I was admitted and kept on Sotalol (was told about the breakthrough flutter since i thought it was a reaction to Sotalol).  They kept me for 5 days while still taking 200mg Sotalol.  Since the breakthrough flutter Sotalol lost it's effectiveness.  In and out of AFib for the 5 days in the hospital.  Pulse would be in the 60's and 70's while sitting and when I would walk across the room to the restroom it would go up into the 120's and 130's.  After seeing my pulse dip into the low 40's one night they stopped Sotalol (it wasn't working anyway since the breakthrough flutter).  I've been home since 5/27.  I'm continuing to take Diltiazem (240mg ER) and Metoprolol (50mg ER).  I purchased a Kardia EKG device.  Really cool.  App on my phone.  You can email results.  Since I've been off Sotalol I've been in normal rhythm every day (all day) except for 3 days since 5/27.  It seems that if I have AFib early in the day I will have it all day long.  Now to talk about Tiksyn.  I've read that Tikosyn is reserved for AFibber's that are very symptomatic, (the drug is dangerous).  I've never had an ablation.  I had a sleep study last week and I'm waiting for the results.  I'm dieting and losing weight (13 pounds lost 47 to go).  I'm thinking that I'm not a candidate for Tikosyn.  What is the definition of very symptomatic?  Could anyone please give me thoughts on this? 

Thanks

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