Automatic ECG import
Reads your ECGs directly from Apple Health. If you like, the app lets you know as soon as a new ECG arrives.
New in 1.1: share cards, therapy timeline & Health medications
Your QTc, at a glance.
Your QTc, at a glance.
Automatically from your ECGs.
SSRI QT Tracker measures QT and heart-rate-corrected QTc from the ECGs in Apple Health – for example from your Apple Watch. Ideal when you start an SSRI or another QT-prolonging medication and want to share your trend with your doctor.
One-time purchase · no subscription · no ads
- iPhone & iPad · iOS 15.1+
- ECGs from Apple Health
- 31 languages
- 100% offline
Trend with risk zones at 450 · 470 · 500 ms
Scan with your iPhone camera
4QTc correction formulas
31languages in the app
100%analysis on your iPhone
0accounts, cloud or tracking
How it works
From your wrist to a trend chart – in three steps
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1
Record an ECG
Take a 30-second ECG as usual, for example with your Apple Watch. It lands in Apple Health automatically.
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2
Automatic analysis
QT Tracker averages all beats into one low-noise beat and finds QRS onset and T-wave end with the tangent method.
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3
Track your trend
Every value lands in your trend chart – with risk zones, baseline and therapy markers. If you like, the app tells you about new ECGs on its own.
In action
The real app – uncut
Two short screen recordings of QT Tracker 1.1, made with sample data.
Interactive
Where exactly does the app measure?
Tap a section of the averaged heartbeat – or play the measurement as an animation.
QT interval
From QRS onset to T end: the complete electrical work of the ventricles. Typical values are about 350 to 450 ms.
QTc calculator
Why QT has to be corrected
The faster your heart beats, the shorter QT gets. QTc converts the value to 60 beats per minute – only then do measurements become comparable. Try it:
ms
bpm
Corrected QTc
For illustration only, not a diagnosis. Limits as in the app: men 450 / 470 / 500 ms, women 460 / 480 / 500 ms.
Live demo
Your trend – just like in the app
Switch range and formula, tap the points. The data is made up, the chart works like the one in the app.
Tap a point for details
Features
Everything you need for your QTc trend
Precise QT measurement
Averaged beat, QRS onset and T end via the tangent method – every measurement with visible measuring points.
Four QTc formulas
Fridericia, Bazett, Framingham and Hodges side by side. You decide which one is your reference.
Therapy timeline
Therapy start and end in the chart, a day axis from the start and a four-week recovery phase after stopping.
Medications from Apple Health
Imports your medications including logged doses from Apple Health (iOS 26 or later). Doses appear as fine ticks in the chart.
Share cards
Status, trend, streak, therapy or badges as an image for story, square or wide format – without raw data.
PDF doctor report
Summary, charts, ECG beats and measurement table – in A4 or as an English US report in Letter format.
Heart rate & HRV
Resting heart rate and HRV (SDNN) from Apple Health as a trend right below your QTc.
Baseline & ΔQTc
Your value before medication – and how far your QTc moves away from it. Alerts at +30 and +60 ms.
Measurement reminders
Gentle reminders so your trend gets enough data points.
CSV export
All measurements as a spreadsheet – for your own analysis or your clinic.
Light, dark, 31 languages
Follows your iPhone's appearance and runs on iPhone and iPad.
Doctor report
A report your clinic can actually work with
One tap turns your trend into a print-ready QTc report. Hand it to your doctor – or keep it with your records.
- Summary with median, baseline, limits and therapy period
- Mean values before, during and after therapy
- QTc, resting heart rate and HRV trends with therapy markers
- ECG beats with measuring points and a complete measurement table
- A4 or US Letter – also as an English clinical report
Page 1 of 3 · Tap to turn the page
Sample with made-up dataBackground
Why the QT interval matters on SSRIs
The QT interval is the time the heart's ventricles need to discharge and recharge electrically. Because it naturally shortens when the heart beats faster, it is normalised to 60 beats per minute – this gives the corrected QT interval, QTc.
Some SSRIs – above all citalopram and escitalopram – can prolong the QT interval in a dose-dependent way. A markedly prolonged QTc raises the risk of a rare but serious heart rhythm disorder called torsades de pointes. That is why prescribing information advises caution, dose limits and, for patients at risk, ECG checks. Regular self-recorded ECGs make a personal trend visible early – and bring real data to your appointment.
Risk zones (men)
- Normal< 450 ms
- Borderline450–469 ms
- Prolonged470–499 ms
- Markedly prolonged≥ 500 ms
For women the limits are 460 / 480 / 500 ms. The app also watches the rise compared with your baseline (ΔQTc ≥ 30 ms or ≥ 60 ms).
Fridericia
QTc = QT / RR1/3The standard – robust across a wide heart-rate range.Bazett
QTc = QT / RR1/2The classic formula, the most widely used in clinics.Framingham
QTc = QT + 0.154 · (1 − RR)Linear correction from the Framingham Heart Study.Hodges
QTc = QT + 1.75 · (HR − 60)Linear correction based on heart rate.Important – please read: SSRI QT Tracker is not a medical device and does not replace a physician's ECG interpretation or a diagnosis. Automatic measurements may differ from clinical assessment and are intended solely for your personal trend monitoring. If you have symptoms such as palpitations, dizziness or fainting – or if your QTc shows 500 ms or more – seek medical advice promptly. Never stop an SSRI or change its dose on your own.
Privacy
Your heart data stays on your iPhone. Period.
100% offline
All analysis runs on the device. The app never connects to a server.
No account
No sign-up, no login, no email address. Install and go.
No data collection
No analytics, no ads, no tracking SDKs. Apple's privacy label: Data Not Collected.
For healthcare professionals
Information for professionals →
Treating patients on SSRIs?
Methodology, sample report, limitations and references – a concise overview for physicians and pharmacists.
FAQ
Frequently asked questions
What does SSRI QT Tracker do?
The app reads ECG recordings from Apple Health, averages the heartbeats into one low-noise beat, measures the QT interval with the tangent method and calculates the heart-rate-corrected QTc using Fridericia, Bazett, Framingham and Hodges. All values appear as a trend with risk zones, baseline and therapy markers.
Which devices does it work with?
With any single-lead ECG in Apple Health – for example from an Apple Watch Series 4 or later. The app runs on iPhone and iPad with iOS 15.1 or later and is available in 31 languages.
Are new ECGs imported automatically?
Yes. The app syncs with Apple Health whenever you open it. You can also turn on a notification that appears as soon as a new ECG arrives – one tap and it is analysed.
Can I import my medications from Apple Health?
Yes, on iOS 26 or later. The app imports medications including start, end and logged doses. You can of course also set the therapy start by hand.
How accurate is the automatic measurement?
QT Tracker averages many beats of a recording and applies the tangent method – the same approach used in clinical QT studies. Still, a measurement from a single-lead ECG can differ from a 12-lead ECG read by a physician. Treat the values as your personal trend, not as a diagnosis.
Is my health data uploaded anywhere?
No. The app works 100% offline on your device. No server, no cloud, no account, no analytics. Share cards and PDF reports are created on your iPhone and only go where you send them.
What do the share cards show?
Only a summary: status, trend, streak, therapy day or badges – optionally with your first name. No raw data or ECG curves are included.
How much does it cost?
A small one-time purchase on the App Store, for example $0.99 in the US. No subscription, no ads, no in-app purchases. Demo mode lets you explore the app even without your own ECGs.
Can the app replace my doctor?
No. SSRI QT Tracker is not a medical device and does not replace a physician's ECG interpretation or a diagnosis. If you have symptoms or a QTc of 500 ms or more, seek medical advice – and never stop an SSRI on your own.
Start your QTc trend today
One-time purchase · no subscription · 100% offline and private
Scan with your iPhone camera