Living with Atrial Fibrillation (AFib)
Take care of your heart.
Sam keeps your resting heart rate, sleep and the symptoms you log. You take that history to your next cardiology appointment.
Step by step: where atrial fibrillation plays out, how a regular heartbeat starts, what changes with atrial fibrillation and how it shows day to day. The model shows the heart and its large vessels without the heart valves.
The heart
Atrial fibrillation is a heart rhythm disorder in the atria, the two upper chambers of the heart. Below them, the ventricles pump blood to the lungs and the body.
Atria / Ventricles
A human figure, seen from the front at an angle. The view moves towards the chest, where the heart turns rose: the two atria on top and the ventricles below. The heart beats at a calm resting pace, the atria a moment before the ventricles.
Heartbeat
Normally, each heartbeat starts in the sinus node, in the wall of the right atrium. The signal spreads across both atria, which contract first; the ventricles follow a moment later.
Sinus node (approx.) / Ventricles / Atria
Close-up of the heart in rose. With each beat a white band starts at the top of the right atrium and spreads across both atria; the atria contract, and a moment later the ventricles below them.
In atrial fibrillation
In atrial fibrillation, fast and disorganised electrical signals run through the atria, so they quiver instead of contracting in a regular rhythm. The ventricles keep pumping, but irregularly and often too fast.
Sketch, not an ECG
Regular rhythm
Even gaps between beats
Atrial fibrillation
Irregular gaps between beats
Disorganised signals / Irregular beat
Same view, slightly closer. Instead of one band, small deep rose rings appear and fade all over the atria, and the atrial walls ripple slightly. The ventricles below keep beating, now at uneven intervals. A sketch compares evenly spaced beats with irregularly spaced ones.
Day to day
Some people notice a racing or pounding heartbeat, skipped beats, tiredness, breathlessness or dizziness; others notice nothing. Atrial fibrillation is confirmed with an ECG, a recording of the heart's electrical activity.
Worth discussing with your doctor.
New or severe symptoms need a doctor. Chest pain, fainting or sudden breathlessness: call emergency services.
Chest area
The view pulls back to the upper body. The heart returns to a neutral grey and keeps beating at uneven intervals, and a soft rose area marks the front of the chest.
Own simplified illustration based on the sources above.
The model shows the heart's atria and ventricles and, for orientation, the large vessels at the heart. The sinus node and the rest of the heart's conduction system are not in the model; the label marks the sinus node's approximate place. The white band stands for the electrical signal of a regular heartbeat; it spreads far more slowly than in the body, so it is still crossing the atria when the heart contracts. The scattered rings stand for the disorganised signals in atrial fibrillation; their number and speed are not true to life. The atrial walls are shown slightly bulged and rippling so the quivering is visible; this is slowed down and exaggerated and is not a change in the size of the atria. Heart valves and the inside of the heart are not shown. The tempo of the heartbeat is an example, not a measured rate, and the soft area on the chest marks where a racing or pounding heartbeat is often felt. Adult male reference model; close-ups and the sketch are not to scale, and the sketch shows only the spacing of beats, not an ECG.
What Sam keeps for you
For people living with atrial fibrillation who want a record for their appointments. Sam is not a medical device. It keeps what you log, plus your resting heart rate and sleep from Apple Health, in one place.
Your Apple Watch, Oura, Whoop or Garmin already records them, and you add what you log. Sam reads them from Apple Health and shows you how they shift against your personal baseline.
Check in on most days, and once a month it becomes a PDF for your appointment.
Heart rhythm is a matter for your cardiologist and for the regulated rhythm features on your Apple Watch. Sam keeps resting heart rate, sleep and what you log.
Sam reads the data your wearable already writes to Apple Health and compares it to your personal baseline - understandable, not a wall of numbers.
Resting heart rate differs a lot from person to person. Sam shows your Apple Health numbers next to your own history, not population norms.
You see sleep, activity and resting heart rate side by side, week by week. What matters for you is something to discuss with your cardiologist.
The free monthly report shows in a PDF what your last weeks looked like. You don't have to report from memory.
Sam is a wellness companion, not a medical device. The app does not diagnose, treat, cure, or prevent any illness and does not replace medical advice. Consult a qualified healthcare professional for medical decisions.
Sam shows your values next to your entries. What they mean is something to talk through with your doctor.
You ask a question, Sam answers with your own numbers. For example:
The monthly report sums up your weeks - for appointments, applications, or simply your own record.
Monthly Report - June
Your Health Overview
Resting heart rate
Activity
Example values. Your report is based on your own data.
Further reading: what wearable data can show about everyday life with Atrial Fibrillation (AFib) - and where its limits are.
The Apple Heart Study puts real numbers on how accurate Apple Watch rhythm detection actually is. What the irregular rhythm notifications and ECG app can actually do - and where they fall short.
A guide to understanding Apple Watch irregular rhythm notifications and ECG for AFib, and how Sam provides context around daily heart patterns - all without replacing medical care.
Alcohol, sleep apnea, and stress are potential triggers for atrial fibrillation. Here's what current ESC guidelines recommend and how wearable data can help you track patterns at home.
A wearable can't detect heart rhythm like an ECG. Here's what resting heart rate and HRV can show if you have atrial fibrillation - and where wearables hit their limits.
The Apple Watch has the ECG app for a 30-second ECG and AFib History with a weekly estimate in percent. Both are Apple features. They show what they record. Whether it is atrial fibrillation is for your cardiologist to say. Sam keeps a symptom diary of the days you had symptoms, plus resting heart rate and sleep.
In Apple's Health app, with its PDF export. Take it to your appointment from there. What your heart rhythm means is something to discuss with your cardiologist. In Sam you log the days you had symptoms in a symptom diary and see resting heart rate and sleep.
The ECG app runs on Apple Watch Series 4 and later, excluding the SE models, and on all Ultra models. Apple lists AFib History for Series 4 and later. Both are intended for people aged 22 or older, AFib History for people with doctor-confirmed atrial fibrillation. Last updated: October 2026.
That's best discussed with your cardiologist. Many people with AFib keep an eye on resting heart rate, sleep, and activity - and those are exactly the signals Sam presents in an easy-to-read way. They arrive without any manual entry, and you can log symptom days alongside them when you want something on the record.
No. Sam is not a medical device and doesn't replace ECGs or checkup appointments. The monthly report can, however, help you prepare for those appointments with concrete everyday data.
That depends on your individual situation and is a decision for your cardiologist. The current ESC guideline names physical inactivity as a risk factor for atrial fibrillation, so staying active generally makes sense. The intensity and type of exercise that suits you is for you and your care team to decide.
You export your AFib History and your ECG as PDFs from Apple's Health app. Sam compiles sleep, stress, activity, sick days and symptom days into a monthly PDF report. For that you log on at least half of the days whether you were sick or well. You also allow notifications and Apple Health access and answer the conditions question.
Help with everyday habits such as enough sleep and going easy on alcohol (more for family members). Call your local emergency number (112 in the EU, 999 in the UK, 911 in the US) immediately for chest pain, severe shortness of breath, fainting or signs of a stroke such as sudden weakness on one side, or trouble speaking or seeing. Sam does not replace medical advice.
Yes, in the symptom diary you log per day what you noticed, such as racing heartbeat, skipped heartbeat, dizziness or shortness of breath. You can add drinking days and sick days. Sam does not record the time or length of an episode. Sam also shows resting heart rate and sleep from Apple Health.
Download Sam for free, connect Apple Health, and see what your data says about everyday life with Atrial Fibrillation (AFib) - compared to your own baseline.
Sam is a wellness companion, not a medical device. Sam does not diagnose, treat, cure, or prevent any illness and does not replace medical advice. For health questions or concerns, always consult a qualified medical professional.