Article

What to Write Down When You Have an AFib Episode

Published 5 August 2026 · 6 minute read · by Bryan, developer of My AFib Companion

Your doctor said “keep a diary.”

Then the appointment ended, and nobody told you what goes in it.

So you write “AFib, Tuesday, felt bad.” Three weeks later that line tells you nothing, and you quietly stop. That’s the normal outcome, and it’s almost never because the person wasn’t trying.

An AFib symptom diary dies because nobody specified the fields.

Here are the fields.

If it is happening right now

You are not going to fill in seven fields while your heart is doing this. Nobody does.

Do this instead. Fifteen seconds.

1. Chest pain, fainting, or trouble breathing? Call 911. Stop reading.
2. Write the time. Just the time. 2:40pm.
3. One word for how it feels. Fluttering. Pounding. Winded.
4. What you were doing. Three words is plenty.
5. Put the phone down.

That’s the entry. It isn’t a good entry. It’s a real one, and a real one beats the good one you never wrote.

Text this to yourself, or say it into a voice memo:

The rest of this page is for afterwards, when you feel like a person again.

The seven things, once you can think

An AFib episode log needs seven fields. You won’t fill all seven every time — get the first three and you’re ahead of most people who walk into a cardiology appointment.

1. When it started — and how sure you are

Write the time. Then write how you know.

“Woke at 3:10 and it was already going” is a completely different data point from “felt it start at 3:10.” Only one of those is a start time. Nobody expects precision; they expect honesty about the precision. Started overnight, noticed 3:10am is a perfectly good entry.

2. When it stopped

Same rule. If you fell asleep and it was gone by morning, write still going at 11pm, gone by 6am. If it hasn’t stopped, write ongoing and come back. An open entry you close later beats a closed entry you invented.

Forums argue endlessly about a 48-hour mark. Don’t take your number from a forum. Ask your cardiologist: “How long is too long for me before I should call you?” Write the answer at the top of your log, where you’ll see it at 3am.

3. Heart rate, at three moments

Before, during, after. Roughly is fine — if you wear an Apple Watch, glance and write the number down. Three numbers beat one, because the shape of the change is what makes a log readable to somebody who does this for a living.

4. What you were doing in the thirty minutes before

Not the whole day. The half hour.

“Stood up off the couch.” “Second coffee.” “Just finished dinner.” “Arguing on the phone.”

This is the field that feels pointless now and becomes useful later. Write it anyway. Patterns turn up months on, when there are finally enough entries to compare.

5. What it felt like — in your words first

People describe AFib in ways that appear on no medical form, and the descriptions are better than the form. A fish flopping around in the chest. Butterflies. Like when you’re exercising and you can’t breathe. Any cardiologist would rather read one of those than the word “palpitations.”

Tag it afterwards if you want. The standard checklist:

palpitations · racing heart · shortness of breath · dizziness · chest discomfort · fatigue · anxiety · lightheadedness · weakness · confusion

Then rate the whole thing 1 to 5. Not clinically bad. Bad for you. Your 4 is a valid measurement of your 4, and the trend in your own numbers is the part worth anything.

Don’t skip anxiety because it feels like it shouldn’t count. “Is this AFib or a panic attack” comes up constantly in every AFib community there is. Recording both is more honest than picking one.

6. What you did — and whether it stopped on its own

Did you take something, lie down, wait it out? Did it stop by itself, or did something stop it? That’s a distinction your doctor cares about and almost nobody records.

7. The boring context

One line: sleep, alcohol, caffeine, large meal, dehydration, illness, stress, heat, cold, exertion.

Honest beats flattering. A log that never mentions the second glass of wine is a log that can’t find the second glass of wine.

The two rules that make a diary worth keeping

Rule one: log the days you’re fine.

Everybody skips this, and skipping it is what makes trigger-hunting impossible.

If you only log bad days, every entry has coffee in it — because you drink coffee every day. Coffee looks guilty. Log the good days too and you find out you drank coffee on eleven good days and two bad ones, and coffee is off the hook. Good days are the control group.

Rule two: log the same way every time.

A messy log with the same six fields every time beats a beautiful log with different fields each time. If you have to choose between complete and consistent, choose consistent.

“Do I bother logging a twenty-minute one?”

Yes.

Not because twenty minutes is significant — I have no idea whether it is, and neither does anyone who doesn’t know your history. Log it because the rule has to be simple enough to survive a bad week. “Log everything I notice” is a rule you can follow at 3am. “Log the ones that seem important” becomes “log none of them” by the end of the month.

What to bring to the appointment

Don’t hand your cardiologist forty pages. Bring the summary: how many episodes since the last visit, the shortest and the longest, the two or three things that keep turning up beforehand, anything that changed, and your three questions written down in advance.

Appointments are short. A summary respects that; a binder doesn’t. Offer the detail if they ask.

Two ways to do this

On paper. A pocket notebook is a perfectly good AFib episode log. So is the Notes app. Copy the seven headings above onto a card, make a stack of them, and keep some by the bed — the 3am episode is the one that never gets recorded.

On your phone. This is what I build, so discount it accordingly. My AFib Companion runs a timer when you tap “I’m having an episode,” so the start time and duration record themselves while you add symptoms and severity. There’s an optional daily check-in — rule one, handled. And it builds a five-section report for your cardiologist, pulling heart rate, resting heart rate, HRV and AFib burden out of Apple Health so you’re not copying numbers off a watch. $9.99/month or $59.99/year after a 30-day free trial, no free tier after that.

The paper version is free and it works. If you’ll be more consistent with a notebook, use the notebook. Consistency is the whole thing; the rest is convenience.

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