My watch ECG says inconclusive
Inconclusive or unclassified means the app could not decide. Here is why that happens, how to get a cleaner recording, and why the strip is still worth saving.
From Dr. Kenny Civello, cardiologist and electrophysiologist
A watch ECG app sorts each 30 second recording into a few bins: normal rhythm, AFib, or a bad signal. When a recording does not fit any of them, the app calls it inconclusive or unclassified. It is the app saying it could not decide.
The app only knows a few patterns
It was built to tell normal rhythm from AFib. Many other rhythms, most of them harmless, fall outside what it can name.
The strip is still useful
The label is the app's guess. The tracing is the real data. A doctor can read it and often tell exactly what it shows.
It is a common result
Extra beats, a fast or slow heart rate, and movement all cause it. Many people get one now and then.
Why was mine inconclusive?
Check anything that applies to you or to that recording. Nothing you enter leaves this device.
What each brand calls it
Each app uses its own words. App labels can change with updates.
| Device | Normal | AFib | Could not decide | Bad signal |
|---|---|---|---|---|
| Apple Watch | Sinus rhythm | Atrial fibrillation | Inconclusive, or Low or high heart rate | Poor recording |
| Samsung Galaxy Watch | Sinus rhythm | AFib | Inconclusive | Poor recording |
| Fitbit and Google Pixel Watch | Normal sinus rhythm | Atrial fibrillation | Inconclusive | Inconclusive |
| KardiaMobile | Normal | Possible atrial fibrillation | Unclassified, Bradycardia, or Tachycardia | Unreadable |
Why some apps say high or low heart rate
Each app only reads rhythms within a set heart rate range. When your rate is above or below that range, the app does not try to name the rhythm. Some apps tell you the rate was out of range. Others just say inconclusive. Either way, the recording can still be read by a doctor.
Record a cleaner strip
Most poor and inconclusive recordings from noise can be fixed. Run through this before you record again.
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Why these steps help
A watch ECG picks up a very small electrical signal. Muscle movement, a loose band, dry skin, and nearby electrical noise all add static to it. Too much static hides the shape of each beat, and the app gives up.
Save it and bring it
Keep every recording, including the inconclusive ones.
Save the recording
Do not delete inconclusive strips. They are often the most useful ones for us to see.
Write down what you felt
Note the time, what you were doing, and any symptoms, or that you felt nothing.
Export it
Most apps let you share a recording as a PDF. The watch alert guide shows how on an iPhone.
Bring it to your visit
Have the PDFs on your phone or printed. We read the tracing itself, not just the label.
Common questions
Does inconclusive mean I have AFib?
No. It means the app could not tell. Many inconclusive strips show a normal rhythm with extra beats. Some show AFib or another rhythm. Reading the tracing is how we find out.
I have a pacemaker. Is a watch ECG still worth doing?
It can be. The app will often say inconclusive because paced beats look different from natural ones. The tracing can still show us your rhythm. Ask us whether recordings would help in your case.
My recordings are almost always inconclusive. What does that mean?
Usually something steady about your heart or your signal, like frequent extra beats, a bundle branch block, or a tremor. Bring several recordings to your visit so we can see the pattern.
How is a watch ECG different from the one in your office?
A watch records one view of your heart's electrical signal. An office ECG records twelve views at once. The watch is good for catching a rhythm at the moment you feel it. The office ECG shows more detail.
Should I buy a different device?
Not because of inconclusive results alone. Every app has the same limits. Getting a cleaner recording and having a doctor read it matters more than the brand.
Other guides
My watch says I have AFibLowering your AFib riskGetting ready for your ablationLiving with a pacemaker or ICDLowering your blood pressureEating for your heartSleeping wellLiving with POTSThis page is general education for my patients. It does not replace advice from your own doctor. Watch ECG apps are not a diagnosis. Device names are trademarks of their makers. This page is not affiliated with any of them.
Based on: Joglar JA, et al. 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation. Circulation. 2024.