#282 How Do You Diagnose Atrial Fibrillation?

How Do You Diagnose Atrial Fibrillation?

If your heart isn’t beating right, you want it diagnosed quickly.  Sometimes it can take years before your doctor can make the correct diagnosis.  If you suspect that you might have atrial fibrillation, this article is for you.  In this article, I will teach you how to diagnose atrial fibrillation.

Melanie’s Experience

Every time Melanie’s heart raced uncontrollably, she rushed to the hospital.  She knew that if she could get to the hospital in time, her doctors could finally make the diagnosis. But they never could.

Instead, they merely diagnosed her with panic attacks.  Despite being labeled with panic attacks, Melanie still knew there had to be something wrong with her heart—something that her doctors couldn’t find.

Melanie isn’t alone.  Many people suffer from atrial fibrillation for years because it never seems to show up on an EKG.

Can an EKG Diagnose Atrial Fibrillation that Comes and Goes?

The problem with the standard EKG is that it is only about a 10-second snapshot of what your heart is doing.  If atrial fibrillation happens to be occurring during those exact 10 seconds, then the diagnosis is easy to make.  However, if you are like most of my patients, atrial fibrillation never seems to happen when the doctor’s EKG machine is running.

What is an Event Monitor?

The key to finally making Melanie’s diagnosis was a much longer EKG—an EKG that continued for an entire month.  This one month long EKG is also known as an event monitor.

An event monitor is a small electronic device that monitors your EKG for prolonged periods of time.  You wear it under your clothes.  You even wear it while you are sleeping.  The only time you take it off is when you shower or go swimming.

Event Monitor vs. Holter Monitor: Which is Best?

Perhaps you have heard of a Holter monitor.  The Holter monitor is usually much larger than an event monitor.  Also, the Holter monitor is taped to your chest for 24 to 48 hours.  During this period, you can’t even shower.

The benefit of a Holter monitor is that it is only 24 to 48 hours.  If your atrial fibrillation happens during this short period, then you are golden.  If, however, nothing happens then it was a waste of time and money.  This is why I generally prefer the event monitor over the Holter monitor.

Besides being stuck with the monitor for a month, the only other drawback of the event monitor is the cost.  Event monitors generally cost much more than a Holter monitor.

If cost is an issue, talk with your doctor about using the Alivecor system described below.  While the Alivecor system probably isn’t covered by your insurance, the $99 you’ll pay is likely much less than the co-pay on an event monitor.

What if the Event Monitor Doesn’t Show Anything?

For some of my patients, a month-long EKG may still not be a long enough period to detect atrial fibrillation.  For these people, more advanced technologies are needed.  Two such possibilities include an implantable loop recorder or a smartphone EKG app.

What is an Implantable Loop Recorder?

An implantable loop recorder is a small chip that cardiologists inject under the skin on your chest.  This chip continuously monitors your EKG for the life of its battery which is generally about three years.

This technology is especially helpful in that any episodes of atrial fibrillation you may be having, even if you are asleep, are automatically recorded and sent to your physician.  All of this happens without you having to do a thing.

The implantable loop recorder automatically communicates with your transmitter at home once a day.  If you are having symptoms, you can do a manual transmission of your EKG to your doctor’s office.

One thing to remember is that while the implantable loop recorder goes in quickly, there is usually a bigger scar getting it out three years later.  Thus, if you don’t want a half inch scar on your chest, then this technology is not for you.

What is a Smartphone ECG app?

The second approach to prolonged EKG monitoring is to turn your smartphone into an EKG machine. This is done through Bluetooth enabled electrodes and a smartphone app.  The best-studied device is the FDA-approved Alivecor system.

If you really want to go high tech on this, you can get it on your Apple Watch.  Hundreds of my patients have used this system with excellent results.  Indeed, studies show that the Alivecor system is one of the best ways to diagnose atrial fibrillation.

Practical Tips

If you think you may be suffering from atrial fibrillation, you need to get it diagnosed.  And you need an EKG to diagnose atrial fibrillation.  Only then can you be appropriately treated.  Knowledge is power, and you have to capture your symptoms on an EKG.

How you do the EKG doesn’t matter.  The key is to document the rhythm.

Of course, don’t try to diagnose atrial fibrillation without the help of your doctor.  Unless you are an EKG master, there will be mistakes. As the stakes are high with heart issues, work with your doctor to correctly diagnose atrial fibrillation.

Disclaimer Policy: This website is intended to give general information and does not provide medical advice. This website does not create a doctor-patient relationship between you and Dr. John Day. If you have a medical problem, immediately contact your healthcare provider. Information on this website is not intended to diagnose or treat any condition. Dr. John Day is not responsible for any losses, damages or claims that may result from your medical decisions.

  1. What are your thought on using alive or post ablation to monitor recurrence of afib…and if no a fib in 30 days no more anticoagulant?

    • Hi Pam,

      Great question!

      According to the guidelines, anticoagulants (blood thinners) are given based on risk factors for stroke. They don’t take ablation status in consideration at all. Personally, I think this approach is wrong.

      Many studies have shown that people who have been successfully ablated have a low long-term risk of stroke. In fact, we have published many studies on this subject. Here is a review article we wrote: https://www.ncbi.nlm.nih.gov/pubmed/29362904

      I also suspect that if you did even more intense Afib monitoring after an ablation, like a daily Alivecor EKG check like you suggested in your question, that you could drive this risk substantially lower.

      Sadly, the Afib guidelines have turned a blind eye to all of the studies showing a low stroke risk in ablated patients. Thus, due to medical-legal issues, I can’t recommend this approach to my patients. However, if my patients choose the approach you are suggesting, then I will definitely support their decision.

      Hope this helps!


  2. I do have Afib and my doctor wants me to do one of two things or both if the first is not successful. I believe it is called cardio-inversion (?) by chemical and 3 day stay in the hospital and if that fails, then shocking the heart back into regularity. What is your opinion on each one and on both? Please tell me the downside of each one. Thank you

    • Hi Gordon,

      I’m guessing the 3-day hospital stay is from starting the drug Tikosyn (dofetilide). As long as the QT interval on your EKG doesn’t prolong, Tikosyn is a well tolerated and safe medication.

      This sounds like a reasonable approach. Try the drug first as in my experience there is about a fifty-fifty chance the drug will put your heart back in rhythm. If the drug fails to cardiovert you, then a shock would be necessary.

      The benefit of this approach would be sinus rhythm for a period of time. Unfortunately, drugs and shocks aren’t usually permanent solutions for atrial fibrillation. In my experience, permanent solutions typically involve significant lifestyle optimization, including weight loss, and an ablation performed at a top-notch atrial fibrillation center.

      The main downside of cardioversion is the risk of stroke. However, if your blood thinners have been appropriately managed this risk is low. Other big risks include the possibility of a cardiac arrest from the drug Tikosyn (dofetillide). Fortunately, this is a very rare event provided your QT interval doesn’t prolong.

      I wish you all the best!!!


  3. Thank you for sharing all your valuable knowledge. Do you have any published notes on extended use of warfarin and the depletion of vitamin k. Does it negatively affect any other organs and bodily functions.
    Thank you.

    • Hi Dorothy,

      This is a great question. I briefly covered this topic in a previous blog post: https://drjohnday.com/9-signs-you-may-have-vitamin-k2-deficiency/

      As warfarin is a vitamin K blocker, there are some studies suggesting that it increases coronary artery calcification and osteoporosis. Personally, I’m not a big fan of this blood thinner. Whenever possible, I prefer one of the newer blood thinners over warfarin.

      Hope this helps!