The PAF medical abbreviation most often means paroxysmal atrial fibrillation, a type of irregular heart rhythm that starts suddenly and stops on its own, usually within hours or a few days. Paroxysmal comes from a word for a sudden attack or fit, which matches the way episodes switch on and off.
Between episodes the heart often beats in a normal pattern, so a routine EKG in the clinic may look fine. PAF turns up in cardiology letters, emergency department notes, monitor reports and problem lists. In lab science and neurology the same three letters have other meanings, covered below. This guide explains the rhythm, how it is classified against other kinds of atrial fibrillation, and how to read the shorthand that tends to sit next to it.
At a glance
Stands for
Paroxysmal atrial fibrillation (most common use)Other meanings
Platelet activating factor (lab science); pure autonomic failure (neurology)Plain meaning
AF that starts and stops on its own, usually within 7 daysSpecialty
Cardiology and electrophysiologyDo not confuse with
Where you see it
Problem lists, monitor reports, discharge summaries
What the PAF medical abbreviation means in heart care
In atrial fibrillation, often written AF or AFib, the upper chambers of the heart quiver with chaotic electrical signals instead of squeezing in a steady rhythm. The lower chambers then beat irregularly and often fast. People may feel a fluttering or pounding heartbeat, shortness of breath, tiredness, dizziness or chest discomfort, while some notice nothing at all.
The word paroxysmal tells you about the pattern over time. In PAF, episodes end without needing a shock or ongoing treatment to stop them, generally within seven days and very often within 48 hours. Episodes can be rare or frequent, and the pattern can change over the years.
How PAF fits among the types of atrial fibrillation
| Type | Usual description |
|---|---|
| Paroxysmal (PAF) | Stops on its own or with treatment within 7 days |
| Persistent | Lasts longer than 7 days, often needs treatment to restore normal rhythm |
| Long standing persistent | Continuous for more than 12 months |
| Permanent | Patient and clinician agree to stop trying to restore normal rhythm |
These labels describe behavior, not severity alone. A person with PAF can still have a stroke risk similar to someone with persistent AF, which is why stroke prevention is judged by risk factors rather than by type.
Decoding a sample note
From a cardiology note: "PAF, CHA2DS2-VASc 3, on apixaban, rate control with diltiazem." The patient has atrial fibrillation that comes and goes. The score of 3 estimates stroke risk from factors such as age, high blood pressure and diabetes. Apixaban is a blood thinner from the DOAC group, and diltiazem slows the heart rate during episodes.
From an emergency note: "Known PAF, presents in AF with RVR, HR 142." Here an episode has started and the heart is racing; RVR means rapid ventricular response.
Other meanings of PAF
Outside the heart clinic, PAF can stand for platelet activating factor, a signaling molecule studied in allergy, inflammation and blood clotting research. It mostly turns up in lab science papers or immunology courses rather than in a patient's chart.
In neurology, PAF means pure autonomic failure, an uncommon condition in which the nerves that control automatic functions such as blood pressure stop working well, often causing a drop in pressure on standing. A neurology clinic letter that mentions orthostatic hypotension and PAF is using this meaning. As always, the setting and the author settle which one is meant.
How episodes are caught and treated
Because PAF comes and goes, catching it can take time. Clinicians may use a wearable monitor for a day or several weeks, an event monitor that records when symptoms occur, or an ILR, an implantable loop recorder placed under the skin. Some consumer watches flag possible AF, but a medical test confirms it.
Treatment notes often fall into three groups: blood thinners for stroke prevention when risk is high enough, rate control medicines such as metoprolol or diltiazem, and rhythm control, which can include antiarrhythmic medicines, a cardioversion written as DCCV, or catheter ablation. Ablation is often discussed earlier for symptomatic PAF.
Charting tips for students
Write the AF type when it is known, because it guides decisions and coding. Note the date and length of the last episode, the stroke risk score, and the current blood thinner. Avoid writing PAF in a neurology or lab context without spelling it out. AF terms sit with other heart rhythm conditions on the diagnosis abbreviations hub for quick comparison.
This page gives general information about chart wording. If your records mention PAF, whoever manages your heart care, a cardiologist or family physician, can talk through your rhythm, stroke risk and any next steps.
Frequently asked questions
What does PAF mean on a heart report?
On a heart report PAF almost always means paroxysmal atrial fibrillation. It is an irregular rhythm that starts suddenly and stops on its own, usually within a week.
Is paroxysmal AFib less serious than other types?
Not necessarily. Episodes may be shorter, but stroke risk depends mainly on factors such as age, blood pressure, diabetes and heart failure, not just on how long episodes last. Your clinician weighs those factors.
Can PAF turn into persistent atrial fibrillation?
It can. Over time some people have longer and more frequent episodes, and the label may change to persistent AF. Others stay in the paroxysmal pattern for many years.
What other meanings does PAF have?
In lab science PAF can mean platelet activating factor, a molecule involved in inflammation and clotting. In neurology it can mean pure autonomic failure, a disorder of the nerves that control blood pressure.