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ECG on Apple Watch | Features & Guide to Setup and Measure

ECG is the main health indicator to test cardio abnormalities. It measures the timing and strength of the electric signals of the heart when it contract. Basically, it looks after the heart rate, rhythm, and electrical activity. Apple Watch has got an electrical heart sensor on Apple Watch Series 3, Series 4 Series 5, and Series 6. It will note the heart rhythm and atrial fibrillation. Apple Watch has got preinstalled ECG app to aid you with the ECG process. Let us look at how to do ECG on Apple Watch with the ECG app.

ECG on Apple Watch

ECG can be measured with the help of the electrical heart sensor in the Apple Watch. There is various stuff you should know before going for the ECG and interpreting the results. ECG app is available on the Apple Watch, and it comes preinstalled. It will help you with the process of monitoring or checking your heart rate. Now follow along to know the process and how does it actually work.

How Does ECG App Work?

Apple Watch has got Electrical Heart Sensor that will read the functioning of the heart. ECG app uses the sensor to study the heart and provide you with the appropriate results (to an extent). In other words, it has got electrodes with which you can measure the heartbeats.

(1) Usually, in hospitals, doctors use 12-lead ECG. Your series 3-6 Apple watches produce results similar to single-lead ECG.

(2) 12-lead ECG measures the electrical signals from the different angles of the heart as 12 waveforms.

(3) Single-lead ECG considers one of these 12 waveforms that is enough to measure the heart rate, rhythm, and classify Atrial Fibrillation or AFib.

(4) It mainly classifies ECG recording into AFib (99.6% accurate) and Sinus rhythms (98.3% accurate). It was tested with 600 subjects in a clinical trial under *ideal conditions in a controlled environment*.


(1) Ensure that the ECG app is available in your country. Click here to check where the ECG app is available.

(2) Ensure your age is 22 years or above because ECGs are intended for older people.

(3) Update your iPhone and or Apple Watch to the latest OS version as not to miss any enhanced features.

(4) Install and setup the ECG app on your Apple Watch. The app will be installed on your watchOS while setting up the Health app on Apple Watch using iPhone.

(5) If not, you can download the app on your watchOS from the Apple Watch app store. Or you can add the app on Watch app on your iPhone.

Related: All you need to know about Activity On Apple Watch

Ideal Conditions to Take ECG

(1) Check if your watchOS is on the right fit on your wrist. It is to note that the back of your watch is touching the wrist.

(2) And the wrist and watch should be clean and dry.

(3) Keep your hand on a flat surface like on a table or lap.

(4) Stay calm and relaxed for an accurate result. Your mood swing can interpret the result largely.

(5) Stay away from the electronics that are active to avoid signal interference.

Setup ECG App on Apple Watch

Set up ECG on Apple Watch
Set up ECG on Apple Watch

Step 1: Install the ECG app on your Apple Watch. In most cases, the app will get installed when you have set up the Health app on your iPhone. You shall get the app from the App Store on Apple Watch.

Step 2: Open the Health App on your iPhone. Follow the on-screen instruction prompts to complete the setup. When ECG app is not shown on Apple Watch, open the Health app >> Browse >> Heart >> Electrocardiograms (ECG) >> Set up ECG App.

Step 3: Open the ECG app after setting up and proceed with taking the ECG.

How to Activate ECG on Apple Watch?

Take ECG on Apple Watch
Take ECG on Apple Watch

Step 1: Tie the Apple Watch around your wrist in a tight fit. The Apple Watch you use is snug and the same as that of the watch you selected in the app. (To check: General >> Watch Orientation).

Step 2: Open the ECG app on your Apple Watch. Make sure that you fulfilled the above-mentioned conditions.

Step 3: Press and hold the Digital Crown with another hand.

Step 4: Release the finger. And wait for up to 30 seconds for the app to finish the whole ECG process.

Step 5: After the ECG process is over, you will receive any one of the classifications. Then you can add symptoms to view and share the result.

View and Share the Results

View and Share ECG results
View and Share ECG results

Step 1: After completing the ECG process, the Apple Watch will provide any classification. You can add or choose the symptoms to your classification. Then tap Done to save the symptoms.

Step 2: Open the health app on your iPhone.

Step 3: Tap the Browse tab. Then choose Heart >> Electrocardiograms (ECG).

Step 4: Tap the chart to get your ECG result.

Step 5: Then tap the Export a PDF for your Doctor. Click on the Share icon on the top-right corner.

Choose the means by which you want to share the result and proceed.

Related: Learn to Close Apps on Apple Watch

Results and Interpretation

You may receive any of the following results or classifications after the ECG.

Result Interpretation
Sinus Rhythm Uniform pattern of beats between 50 BPM and 120 BPM. Both upper and lower heart chambers are in sync.
Atrial Fibrillation The heart is beating in an irregular pattern between 50 BPM and 120 BPM. It indicates irregular rhythm or serious Arrhythmia.
Low or High Heart Rate The app cannot detect the heart rate under 50 BPM or over 120 BPM.
Low – Medicines or improper electrical signals.
High – Physical activities, or dehydration, infection, alcohol, AFib or Arrhythmia.
Inconclusive The recording cannot be classified. Which means either the conditions are not fulfilled or constant inconclusive results may indicate various other features.

Keep in Mind

  • All the above results are true only to a certain extent. Consult with a doctor for a better interpretation.
  • Do it in supervision and share the results with a doctor for the correct result and further procedure.
  • If your result is Sinus rhythm, but you have any discomforts and symptoms, contact the doctor.
  • AFib and Inconclusive doesn’t mean you are having health issues. So don’t panic.
  • The app cannot detect a heart attack, so if you have any chest pain or pressure, or tightness or any other symptom, call emergency.
  • No blood clots or stroke can be detected, or any other-heart related conditions like BP, cholesterol, failure, or Arrhythmia.

The results are accurate only to a certain extent, with ECG on watchOS. Consult a doctor for a better perspective or to know your heart health. Do not conclude results on your own and take any medications.