EP QTc vs QTc Tracker for SSRI & SNRI

This app collects over 30 published formulas for calculating the corrected and predicted QT interval (QTc and QTp). Included are details on each formula and reference links. Results are analyzed statistically and graphed. Published definitions of normal and abnormal QTc intervals are also included. This is no ordinary calculator that just gives you the results of Bazett's formula. If you are interested in this fascinating corner of electrocardiology, this app is for you.

QTc Tracker automatically analyzes your smartwatch ECGs from Apple Health and computes the QT and QTc interval – ideal for keeping an eye on your heart when starting, during and after SSRI therapy or other QT-prolonging medication. • Automatic import of your ECGs from Apple Health – optionally with a notification whenever a new ECG arrives • Precise QT measurement using the tangent method on an averaged, low-noise heartbeat • QTc via Fridericia, Bazett, Framingham and Hodges • Clear trend chart with zones (450 / 470 / 500 ms), baseline and trend line – for 1 month, 6 months, 12 months, the therapy or everything • Therapy start and end: baseline before the start, trend during therapy, recovery afterwards • Import medications and logged doses from Apple Health (iOS 26 or later) • Resting heart rate and HRV (SDNN) trends • Doctor's report as PDF: trend, ECG traces with measurement points, measurement table, medications with dose – in A4 or US Letter • Share cards for social media: “QT normal” – honest even when readings stand out • Measurement reminders, CSV export, light and dark mode, 31 languages • 100% offline: no cloud, no account, your data is never shared How it works: Record an ECG with your smartwatch. QTc Tracker reads it from Apple Health, averages the beats into a clean signal, and detects the QRS onset and T-wave end with the tangent method. From these it derives QT and the rate-corrected QTc values that you can follow over time. Important: QTc Tracker is not a medical device and does not replace a physician's ECG interpretation or diagnosis. The automatic measurement may differ from clinical assessment and is intended solely for your personal tracking. If you have symptoms or a QTc of 500 ms or more, seek medical advice, and never stop an SSRI on your own.