Newly diagnosed with atrial fibrillation: what comes next, what to ask the cardiologist, and what to record until the appointment

After an atrial fibrillation diagnosis comes a phase of clarification. Until the next appointment you can record when you feel symptoms, put together your medication list, and write down your questions. Note the complaints on paper or in the symptom diary in Sam, where you pick palpitations or dizziness with a strength on the day. Which treatment fits you, you decide together with your cardiologist.

This text is not a treatment guide. It says what is usually clarified in the first weeks, which questions are worth asking, and what an Apple Watch can and cannot do.

What the diagnosis means, and what it does not

Atrial fibrillation is a heart rhythm problem. The upper chambers quiver instead of beating steadily, and the heart beats irregularly and often too fast. The British Heart Foundation calls it a common abnormal heart rhythm. The American Heart Association says AFib can lead to blood clots, stroke and heart failure.

That sounds serious, so here is the calm part. The British Heart Foundation calls AFib manageable and says that with the right treatment and lifestyle, you can still live well with it. How that applies to you is for your cardiologist to say. The key is that it raises the risk of stroke over time, so your personal stroke risk belongs in every conversation with your cardiologist. The CDC notes that AFib is linked to about a fivefold higher ischemic stroke risk and causes about 1 in 7 strokes.

The course differs for everyone. It often starts with short episodes that stop on their own, and some people feel little or nothing. Which form you have, your doctor tells you.

What doctors usually clarify next

Once AFib is confirmed, further checks follow. The NHS, the British Heart Foundation and the US National Heart, Lung, and Blood Institute describe these steps:

• In the conversation, it is about your symptoms, other risk factors and conditions, and whether AFib runs in the family.
• A physical check looks at your pulse and blood pressure.
• An ECG records your heart's rhythm and electrical activity. Because episodes come and go, a longer recording with a Holter or event monitor may be used.
• An echocardiogram shows the size and function of the heart chambers and the valves.
• Blood tests can help look for possible causes, such as thyroid problems or the level of potassium.
• A chest X-ray may also be part of the checks.

The NHS says that if a GP thinks you could have atrial fibrillation, they refer you to a heart specialist, a cardiologist. Which steps fit you depends on your situation and your doctor's judgment.

Questions for your next cardiologist visit

Write the questions down first. In the conversation they are easy to forget. These are worth asking:

• What type of atrial fibrillation do I have, and how was it confirmed?
• Is there a cause or other condition we should check, such as blood pressure, thyroid or sleep apnoea?
• How do you assess my stroke risk?
• Might blood-thinning medicine be a topic, and what speaks for or against it?
• Which options exist to ease my symptoms, and which might suit me?
• Do my current medicines fit my new situation?
• Which checks come next, and when?
• What should I watch with alcohol, exercise and daily life?
• From when should I contact you before the next visit?

Also ask for a copy of the clinic letter and the ECG result, so you have both at every later appointment.

What you can record in the meantime

Write symptoms with date and time: when something began, roughly how long it lasted, and what you felt, such as palpitations, a racing heart, breathlessness, dizziness or exhaustion. Add what was going on, such as resting, the stairs or an evening with alcohol. These are observations, not explanations. An example: "Tuesday, 21:40 to about 22:30, first palpitations, then a racing heart. I was on the sofa after a short night." Many episodes pass unnoticed. You record only what you feel.

For medicines, write down everything you take, including over-the-counter products and supplements, and every change since the diagnosis. If you take something differently from prescribed, say so openly. If you already received medicine, for example to prevent clots, do not change anything without speaking to your doctor. Apple gives the same advice for AFib History. For what alcohol, sleep and stress have to do with AFib, see AFib triggers: alcohol, sleep and stress.

Bring the clinic letter, the ECG result and lab values in a folder. Photos or copies are enough for the conversation. If you want context on why resting heart rate matters, see resting heart rate and AFib.

What your Apple Watch can do, and what it cannot

Three Apple features touch the heart rhythm. All three belong to Apple, not to Sam. Availability depends on your country or region, so check Apple's feature availability page.

The ECG app runs on Apple Watch Series 4 and later and all Ultra models, not on the SE. Apple built it for people aged 22 and over. You hold a finger on the Digital Crown for 30 seconds. The result can be "sinus rhythm" or "atrial fibrillation", and you can add symptoms and export a PDF for your doctor. Apple states the ECG app cannot detect a heart attack, blood clots or a stroke, or other heart conditions.

For AFib History, Apple requires a physician diagnosis of AFib and an age of 22 or over, which you confirm during setup in the Health app. For consistent estimates, Apple says to wear the watch at least 12 hours a day on 5 days a week. When enough readings exist, a weekly estimate arrives on Mondays: what share of the previous week your heart showed signs of AFib. It never shows 0%, but "2% or less", and it also exports as a PDF.

Whether a watch recording counts for your clinic is for your doctor to decide. Apple's irregular rhythm notifications are not meant for people already diagnosed with AFib, and Apple turns them off when you set up AFib History. For the setup, see how to set up Apple Watch for AFib and what an Apple Watch can and cannot show about AF.

When you do not wait for the appointment

Not everything waits for a visit. The NHS says to call the emergency number when you have a fast or irregular heartbeat together with chest pain, shortness of breath, sweating, feeling sick, fainting or dizziness, or signs of stroke such as weakness or numbness on one side, blurred vision or trouble speaking. Use your local emergency number (112 in the EU, 999 in the UK, 911 in the US). Do not drive yourself to hospital.

A watch cannot catch a stroke. For everything else that makes you unsure, call your doctor's office (in the UK, your GP). You do not have to sit out the appointment in silence.

Log your symptoms in Sam and bring the monthly report to the cardiologist

You go to the cardiologist with a course of symptoms instead of relying on memory of which days flopped.

• Instead of loose notes: you pick palpitations, a racing heart or breathlessness with a strength on the day, one tap. Your symptom days and top symptoms build the monthly report you can show at the visit.
• Instead of a notes app: the report gathers your symptom days for you, so you do not have to count them by hand.
• There is no program for atrial fibrillation in Sam, and Sam does not show ECG data. For someone without a program, the symptom diary is the honest place.

Your cardiologist decides what any of this means. Sam records what you feel.

Try Sam for free

Sam is a wellness companion, not a medical device. The app does not diagnose, treat, cure or prevent any condition or health state. Always consult qualified professionals for medical decisions.

Related reading

• Resting heart rate and AFib
• AFib triggers: alcohol, sleep and stress
• How to set up Apple Watch for AFib
• Apple Watch AFib History vs rhythm notifications and ECG

Sources

Updated: October 2026

• British Heart Foundation: Atrial fibrillation (published 20 March 2024)
• NHS: Atrial fibrillation (last reviewed 13 January 2025)
• US National Heart, Lung, and Blood Institute: Atrial fibrillation diagnosis
• American Heart Association: Atrial fibrillation
• CDC: About atrial fibrillation (May 2024)
• Apple Support: Take an ECG with the ECG app on Apple Watch (September 2026)
• Apple Support: Track your AFib History with Apple Watch (September 2026)