A Primer on Atrial Fibrillation: Causes, Treatments, Stroke Prevention, and Monitoring

Atrial fibrillation occurs when the normal, regular, synchronous action of the upper chambers of the heart becomes chaotic, rapid, and inefficient.

Some who go into atrial fibrillation know it right away because they feel bad-they feel what we doctors term palpitations: a sensation that their heart is beating rapidly or irregularly (like a fluttering.) They may have other symptoms associated with this such as dizziness, chest pain, anxiousness or shortness of breath.

Many, however, go into atrial fibrillation and are not aware of it (aka they are asymptomatic.)

For those who are asymptomatic, the first symptom felt may be due to a stroke from a clot developing in the (now dysfunctional) left atrium, or upper chamber of the heart, dislodging and going down an artery to the brain. For others, especially if the heart rate is high, heart failure may develop, causing shortness of breath and prompting medical evaluation.

It is natural to wonder “Why Did I Go Into Atrial Fibrillation?” For some individual cases, specific triggers can be identified but for many, we never identify a particular cause.

For most patients persistently in atrial fibrillation, I recommend utilizing a combination of medications and cardioversions to restore the normal rhythm (normal sinus rhythm.) This is termed a “rhythm” management strategy. For decades we did not have solid evidence supporting this strategy over a “rate” strategy.” A rate strategy is a conservative approach in which the patient is left to permanently be in atrial fibrillation but heart rate and stroke risk are controlled by medications.

I discussed in detail why I recommended the rhythm strategy in “Why I Favor The Restoration and Maintenance of Sinus Rhythm For Most Patients With Atrial Fibrillation.” Since I wrote that strong evidence has emerged supporting this position beginning with the 2020 Eastnet-AF trial I discuss below.

Whether you choose a rhythm or a rate strategy, the second major decision for AF patients is whether to take an anticoagulant to reduce the risk of atrial clot formation and resulting stroke. A good starting point for this discussion is “Blood Thinners (Oral Anticoagulants) For Atrial Fibrillation: Who Should Take Them and Which One To Take.

Diagnosing Atrial fibrillation

Atrial fibrillation is identified in myriad ways. Some patients feel very sick when they first go into it and end up in the emergency room. Others note the marked increase or irregularity in their heart beat alone and have it diagnosed by ECG in a doctor’s office. Irregular pulse or heart beat can be detected by many wearables and home BP devices which can alert users to the possibility of atrial fibrillation.

You can even take your own pulse and prevent a stroke by identifying atrial fibrillation.

There are thousands of patients now with permanent pacemakers and implanted defibrillators, devices which continuously monitor the heart rhythm. Brief, transient, and silent episodes of AF are often detected by these devices. Such episodes of “subclinical” atrial fibrillation are regularly detected with long-term monitors and loop recorders. I discuss current uncertainty around what to do with subclinical atrial fibrillation in “Subclinical Atrial Fibrillation: Seek and Ye shall Find, But What Then?

Sometimes strokes present in unusual ways, like the inability to differentiate a spade from a diamond when playing bridge (described in TIAs and silent atrial fibrillation.) and afib can be the cause.

Using Personal ECG Devices To Diagnose Atrial Fibrillation

I’ve written extensively on the value of personal ECG devices to detect and monitor atrial fibrillation. There are two that I have considerable patient experience with and highly recommend:

  1. AliveCor’s Kardia

Using a Smart Phone Device and App To Monitor Your Pulse for Atrial Fibrillation (AliveCor)

AliveCor Is Now Kardia and It Works Well At Identifying Atrial Fibrillation At Home And In Office

    2. Apple Watch 4 and higher

           Apple Watch posts (here, here and here)

Devices/Apps I do not recommend for AF detection

Do NOT Rely on AF Detect Smartphone App To Diagnose Atrial fibrillation

Sonohealth’s EKGraph 


Stroke Risk and Stroke Prevention

The most serious adverse consequence of having atrial fibrillation is stroke. Since we have safe and effective ways of preventing afib-related stroke with oral anticoagulant drugs (blood thinners), a major decision for the newly diagnosed patient with atrial fibrillation is “should I take a blood thinner?”

To answer this question the afibber should engage in a lengthy discussion with his/her health-care provider which results in a shared and informed decision. Such discussion must cover your risk of stroke, the benefits of blood thinners in preventing stroke, the bleeding risks of blood thinners, and the pros and cons of the various anticoagulants available to prevent stroke.

As background for these physician discussions, I highly recommend reading my post on “Which Patients Should Take Blood Thinners” which discusses stroke risk, anticoagulant risk, and the lack of efficacy of aspirin in this area.

Estimating Stroke Risk in Patients With Atrial Fibrillation You can estimate your stroke risk using an app that utilizes the CHAD2DS2-VASc score. I prefer to call the Lip score. This post was written in 2015 but the CHADS2 score is still the primary tool for assessing afib related stroke risk.

Why Does the TV Tell Me Xarelto Is A BAD Drug? Anticoagulant drugs that prevent the bad clots that cause stroke also increase bleeding risk. A bleeding complication is not a valid reason to sue the manufacturer.  The lawsuits are strictly a money-making tactic for sleazy lawyers.

All patients with afib do not need anticoagulant therapy chronically. For some, we offer a pill-in-the-pocket approach, something I’ve touched on a few times on my blog.

Procedural alternatives to anticoagulant therapy have been developed including closure or obliteration of the left atrial appendage at the time of open heart surgery and closure using a catheter-based technology without surgery (left atrial appendage occlusion.) I have only referred rare patients for the FDA-approved catheter-based closure devices. For a good discussion on this area see Dr. Mandrola’s article entitled “Left atrial appendage occlusion should be offered only to select atrial fibrillation patients.

Treatment Of Atrial Fibrillation

        Lifestyle Changes

Eight Lifestyle Changes to Prevent Atrial Fibrillation


How Obesity Causes Atrial Fibrillation in Fat Sheep and how Losing Weight can reduce the recurrence of atrial fibrillation.

More recently we have solid evidence that sustained weight reduction can significantly reduce the recurrence of AF from the Australian LEGACY study 


Acute and Chronic Influences of Alcohol on Atrial Fibrillation

The alcohol AF trial published in NEJM showed abstinence from alcohol significantly reduced symptomatic episodes and hospitalizations for AF

-Fish Oil Supplements

Omega-3 Fatty Acids, Fish Oil Supplements and the Risk of Atrial Fibrillation discussed evidence that high-dose omega-3 supplements may cause atrial fibrillation.


The most compelling evidence for the independent role of exercise in reducing AF comes from a Norwegian study of 51 patients with AF who were randomized either to aerobic interval training (AIT) or to their regular exercise habits. The exercise arm had a lower burden of Afib

An accompanying editorial provides this graphic on the benefits of exercise training in AF

Drug Therapy: Rate Control and Anticoagulation

Foxglove Equipoise. When William Withering began treating patients suffering from dropsy in 1775 with various preparations of the foxglove plant he wasn’t sure if he would help or hurt them. After 240 years of treatment, we are still unsure if the drug obtained from foxglove is useful.

Should Digoxin Still Be Used in Atrial Fibrillation? The answer is it still has a minimal role in chronic outpatient therapy. In hospitalized patients we use it frequently intravenously to aid in slowing heart rate in hypotensive patients with rapid afib.

Drug Therapy: Antiarrhythmic Drugs for Maintenance of Sinus Rhythm

If lifestyle changes alone can’t control atrial fibrillation, I am an advocate of enlightened use of medications (antiarrhythmic medications or AADs) that can safely restore and maintain the normal sinus rhythm long term.

The most recent study supporting drug therapy for suppressing atrial fibrillation, EAST-NET AF

My three-part series on “enlightened medical management of AF”:

Part I: Amiodarone. Kardia and Cardioversions

Part II: The Pill-in-Pocket Approach

Part III: Flecainide for Chronic AF Suppression

There are other medications one can utilize for maintenance of sinus rhythm but I utilize them much less commonly than amiodarone and flecainide.

I discuss sotalol (Betapace) and beta-blockers here. Dofetilide (Tikosyn) is another alternative for the suppression of atrial fibrillation. Both of these drugs should be started in the hospital with the patient on an ECG monitor for 72 hours to monitor for ventricular tachycardia and QT prolongation.

I don’t recommend Multaq (aka amiodarone light) and have a post pending on this topic.

Cardioversion and Ablation

We can shock (cardiovert) the heart back to normal rhythm with little risk and a very high success rate when performed by experienced and enlightened cardiologists. Keeping the rhythm normal after successful cardioversion is a bigger challenge (see above) and when medications and lifestyle changes fail an invasive procedure (ablation) is an option for some patients. Ablation should not be considered a cure for AF as recurrence is common and successful ablation has not been shown to lower stroke risk thus anticoagulants are still recommended lifelong after the procedure.

Cardioversion: How Many Times Can You Shock The Heart?

Ablation: Cautionary Words From Dr. John Mandrola and The Wisdom of a Team Approach

Catheter Ablation of Atrial Fibrillation: Will it Reduce Your Risk of Death, Serious Bleeding or Stroke? 

Ablation For Atrial Fibrillation: One Patient’s Experience


What Happens If You Go Into Atrial Fibrillation On A Cruise?

Apple watch versus Kardia to monitor atrial fibrillation from home: A case study

Antifibrillatorily Yours,



9 thoughts on “A Primer on Atrial Fibrillation: Causes, Treatments, Stroke Prevention, and Monitoring”

  1. I had 2 ablations in 2001 at Cleveland Clinic and have been free of AF since! I am not on anticoagulants and check my heart EKG on my Apple Watch. A past cardiologist wanted me on an anticoagulant after all those years, I refused. In asked her to order my calcium artery test, it showed 0%. I am 73 year old female retired RN, I am not on any meds, except for BP.

    • Vicky,
      How often do you check your AW EKG?
      When AFIB recurs after ablations it is often silent.
      If your only CHADS2 risk factors are age and gender female then the balance of risk and benefit for anticoagulation is about the same.
      But, the coronary artery calcium test does factor into that risk. CAC is looking for risk of MI , stroke related to atherosclerotic CV disease an entirely different entity from afib.
      Dr. P

  2. Too little attention and research is focused on paroxysmal AF. Patients that spend less than 10% of life in AF are not the same as those with a larger “burden” of AF. Drugs/cardioversion/ablation trials should INDEPENDENTLY assess efficacy in PAF vs AF.

      • Guidelines don’t differentiate recommendations based on paroxysmal versus persistent.
        I take a patient-by-patient approach to anticoagulation. in addition to evaluating the standard CHADS2 risk score I look at what factors have triggered AF, duration, ability of patient to self-monitor or recognize when they are in AF, bleeding risk factors, and patient preference.
        After reviewing all these factors and presenting options to patient in some cases of PAF we utilize a “pill-in-the-pocket” approach which means no anticoagulation unless patient recognizes they are in AF. They have a prescription for apixaban which they begin upon recognition of AF.
        Dr. P

  3. Thank you so much for this description of Afib and treatments. 4 to 9 episodes a month. Always self convert.
    On eliquis and diltiazem. Wish I could take a rate control drug, but have had lousy side effects from them.

  4. I wonder about the necessity of taking an anti coagulant after a successful ablation.

    I was on warfarin and required two trips to the emergency room for very severe nose bleeds.

    I have been in NSR for the past 18 months and am in excellent health although I am I am 79 years old.

    • Richard,
      It would be great if we had studies showing under what conditions you could stop oral anticoagulants after catheter ablation of atrial fibrillation.
      Guidelines recommend continuing them indefinitely.
      This paper found in a large US national registry that patients were being taken off anticoagulants post ablation and found no different from patients treated with medications “in adjusted rates of cardiovascular or all-cause death between patients treated with AF catheter ablati: on and antiarrhythmic medications only. Notably, discontinuation of OAC after ablation remains relatively common despite guideline recommendations for continued stroke prevention therapy in patients at risk of stroke.”


Please leave your comments. The skeptical cardiologist loves feedback. He reads all and replies to all that warrant a reply.