Guest post: Types of atrial fibrillation

By Howard Rodenberg, MD, MPH, CCDS

Some words are just fun. Fun to say, fun to spell, fun to use. One of those words, in my opinion, is quiver. Say it out loud. “Quiver, quiver, quiver.” You can’t help but smile.

Because I’m a huge fan of the word quiver, I’m delighted when I get to talk about atrial fibrillation (AF), for fibrillation is simply the clinical word for “quiver.” Fibrillation is, technically speaking, the rapid, irregular, and unsynchronized contraction of muscle fibers. While we most often think about fibrillation in terms of cardiac muscle, fibrillation can happen in any kind of muscle tissue. We may give it different names; in skeletal muscle we tend to call it fasciculation because the contraction occurs at the level of the muscle bundle rather than the individual muscle fiber, but it’s quivering just the same.

A quick note: AF’s cousin is atrial flutter, in which there is coordinated atrial tachycardia mediated by delayed conduction within the atrioventricular (AV) node. The coordinated contractions look like “shark fins” in between the normal QRS complexes (a combination of the Q wave, R wave and S wave). So, when I see an EKG with atrial flutter, my first reaction is to put the EKG down on the desk, hold my hand out flat perpendicular to the tracing, make sure my thumb points skyward, and move my little finger up and down while I murmur the words of Mack the Knife. The other thing I’ve done is to hold the EKG above my head, crouch down close to the floor, and sneak up behind a nursing student going, “Duh duh. Duh duh. Duh duh duh duh duhduhduhduhduhduhduhduh DAAAAA!” They hate that.

AF is pretty ubiquitous—at least enough to be the subject of television commercials. And because it’s so common, there are a number of terms used to describe it. Most traditional definitions of AF have been time-based. Is the arrhythmia intermittent or is it always there? How long has it been around? But, in the era of aggressive electrophysiologic interventions, such as ablative therapy, there’s a new layer of definition that involves intent to treat.

It’s important to clarify what we mean by “intent to treat.” AF is clinically addressed in many ways. Medications are given to keep the ventricular rate under control. Others are given to prevent complications such as a stroke. However, these are not really treating AF, trying to correct the problem; they are instead managing the disease. Treatment of AF itself means stopping the arrhythmia through pharmacologic or electrical means. So, while a patient may be receiving a beta-blocker and an antiplatelet agent to prevent the recurrence or complications of the AF, if there is no intent to restore the normal sinus rhythm, there is no intent to treat the AF.

The concept of “intent to treat” helps us to understand the four classes of AF, as used in current electrophysiology practice:

• Paroxysmal AF (PAF): Intermittent AF with episodes lasting less than seven days at a time.
• Persistent AF: AF is present most or all of the time, with intermittent episodes lasting more than a week.
• Longstanding Persistent AF: Persistent AF for more than a year with intent to treat at some point and restore normal sinus rhythm.
• Permanent AF: Persistent or longstanding persistent AF where no further attempt to maintain sinus rhythm is planned.

There are a few important caveats here. One is that the terms “acute” and “chronic” AF don’t exist in practice. They have no real meaning as they convey no information regarding the duration of the arrhythmia nor the intent to treat.

The second is that there is really no way, short of reading a narrative, that a coder or CDI specialist is able to determine intent to treat without the proper terminology, as the clinical indicators (specifically medications) for most types of AF are essentially the same.

Finally, intent to treat is fluid. A patient with persistent AF may not be a treatment candidate while undergoing chemotherapy for cancer, and at that time may be considered to have permanent AF. Once the cancer is in remission, however, circumstances may change sufficiently that the patient may be a candidate for treatment once again under the label of longstanding persistent AF.

Like everything in coding world, these differing definitions have implications. And, like many things in coding world, these implications have absolutely no similarities to clinical practice. Patients with all forms of AF may be on aggressive medical therapy, including anti-arrhythmics to control heart rate and anticoagulants/antiplatelet agents to prevent atrial clot formation and decrease the risk of stroke.

(On a personal note, the principal diagnosis for anyone on an anticoagulant or antiplatelet agent should get an automatic MCC because nothing good happens when a patient on one of these medications is hospitalized. Nothing.)

But the coding world only recognizes persistent AF as worthy of assignment as a CC. Clinically, this makes no sense. If all these patients are on similar medications, then all are at similar risk (those with permanent AF even more so than the group with persistent disease). Despite the clinical contradiction, understanding that persistent AF “counts” as a CC and the other forms of AF do not make specificity in the documentation of AF a key part of ensuring that the record best reflects the patient’s severity of illness and needs for care.

Editor’s note: Rodenberg is the adult physician advisor for CDI at Baptist Health in Jacksonville, Florida. Contact him at howard.rodenberg@bmcjax.com or follow his personal blog at writingwithscissors.blogspot.com. Advice given is general. Readers should consult professional counsel for specific legal, ethical, clinical, or coding questions. Opinions expressed are that of the author and do not represent HCPro or ACDIS.