Atrial Fibrillation – AFib

South Denver Cardiology is home to six cardiac electrophysiologists (EP) who specialize in the prevention and treatment of abnormal heart rhythms. Sri Sundaram, MD, is one of the EP doctors who specializes in AFib and shares some facts on what AFib is and how it is treated.


What is Atrial Fibrillation? What is AFib?

AFib is an unorganized, chaotic rhythm that originates from the pulmonary veins in the left atrium (the top left chamber of the heart). The cells in the pulmonary veins ordinarily do not have any electrical activity, but in those with atrial fibrillation, they gain electrical activity and start firing in a rapid, irregular pattern. A-fib is described as an irregularly irregular rhythm in which the heart beats without a regular pattern.

The exact cause of atrial fibrillation is unknown.  As scientists, we are still determining what causes this chaotic rhythm.  We do know there is an association with hypertension, sleep apnea, thyroid abnormalities, and excess alcohol and caffeine intake. However, about 50% of patients that have AFib don’t have one of the factors with a strong association.

As scientists, we have not identified a specific gene responsible for AFib, so we cannot say if you will get it when another family member has it. That being said, I have taken care of multiple families that have three generations with atrial fibrillation.

AFib is a progressive disease.  Unless there is an underlying cause that can be corrected, it always gets worse over time.  It initially starts as paroxysmal atrial fibrillation when it comes and goes.  Over time, the episodes start increasing in length and severity.  Patients start having more and more events to the point that they are now in it all the time.  That’s when it progresses and is called persistent atrial fibrillation.  Inside the heart, that usually means that it has spread beyond the pulmonary veins. The success of the treatment is lower, the longer a patient has A-fib, and the more it progresses.

Afib Treatment

Treatment for AFib is divided into two approaches –  rate vs. rhythm control.

Rate control is the usual first step and is used when fibrillation is not as severe, or the episodes are rare. This approach consists of using medications to keep the HR from getting too fast or too slow.   Simple high blood pressure drugs are the most commonly used.   As the atrial fibrillation progresses, rhythm control is the next step.  This approach involves treatment with anti-arrhythmic medications.  These are drugs specifically meant to treat AFib.  The success of these drugs is limited, and the stronger the drug, the more the side effects.

If the drug approach doesn’t work or is not tolerated well by the patient, the next step is catheter ablation.  That approach consists of placing wires from the groin that are advanced into the pulmonary veins in the left atrium.  There is a burning (Radiofrequency) and a freezing (Cryoablation) method that is used to electrically isolate the pulmonary veins so that the atrial fibrillation electricity from the pulmonary veins cannot get into the heart.  Success rates for this procedure can vary from 50-80%, depending on the individual patient.  The ablation can be done several times. Finally, if the ablation fails, there is a surgical option called the surgical maze.

Aside from treatment for the rhythm, most patients will need treatment with blood thinners.  Atrial fibrillation is the number one cause of stroke in the United States as the left atrium beats irregularly, blood pools, and eventually forms a clot.  If the clot breaks off and goes to the brain, it causes a stroke.  Blood thinner options can be aspirin for someone that it is a low risk of a stroke.  For patients at higher risk of a stroke, more potent blood thinners such as Warfarin/Coumadin may be needed.

Additionally, there are newer blood thinners that have recently been introduced, and as a group is called the DOACs (Direct Oral AntiCoagulants). For patients that have failed blood thinners, there is an alternative to occlude the left atrial appendage.  The appendage is the part of the Left atrium where the clots form.  Occluding devices can be placed that cover the appendage and have been shown to be the equivalent of taking blood thinners.


Dr. Sundaram discusses Left Atrial Appendage (LAA) Closure and new Pacemaker technology


Learn more about the treatment of LAA closure here on our Structural Heart Clinic page.


A-Fib Symptoms

The symptoms of atrial fibrillation are quite variable.  Some patients have no symptoms while others have severe, disabling symptoms.   Fatigue and shortness of breath with ordinary activity is the most common symptoms.  Palpitations (“like a fish flopping in my chest”), lightheadedness, passing out, chest pain, chest discomfort, headaches, not thinking as clearly and chest burning are common descriptions.

In the long term, Atrial Fibrillation has also recently been linked to having higher rates of dementia, more hospitalizations, increased stroke rate and even higher incidence of heart attacks.  Researchers are currently evaluating if there is a change in lifespan associated with afib.

South Denver Cardiology is a leader in the treatment of Afib and we may be able to help you or a loved one who has A-fib. If you would like to schedule an appointment with any of our Afib specialists click here, or feel free to call us at 303-744-1065