ECG Analyzer
Apple Watch ECG AnalysisABOUT
Advanced ECG interpretation for Apple Watch users
ECG Analyzer is a third-party ECG analysis app that goes beyond Apple's basic sinus rhythm / atrial fibrillation classification. It captures your Apple Watch electrocardiogram data and provides detailed heart rhythm interpretation — examining intervals, waveform morphology, and trends over time.
With 1,383 ratings and 4.7 stars on the App Store, it's trusted by users managing conditions like bradycardia, palpitations, and post-procedural monitoring. The app makes Apple Watch ECG data actually useful by translating clinical parameters into plain-language explanations you can understand and share with your doctor.
- Detailed ECG waveform analysis beyond basic rhythm classification
- Heart rate, QRS duration, QT interval, and ST segment tracking
- Historical comparison — track ECG changes over weeks and months
- Plain-language explanations of clinical findings
- Export-ready reports to share with your physician
- Apple HealthKit integration for seamless data access
REVIEWS
What users say
I love this app. I have Bradycardia and this app has saved me on many occasions where I feel very dizzy or extremely drained. I'll check the app and it shows me what I need to see. It helps me keep control of my heart.
I have been suffering from palpitations for around 2 years and got the watch to monitor my heart. The app has been a reliable tool to interpret my data since. Very straightforward display and verified. Plan to continue using the app as found no issue.
FAQ
Frequently asked questions
How do I analyze my Apple Watch ECG results?
Apple Watch records ECG data as a single-lead electrocardiogram (Lead I) by measuring electrical signals between the crown sensor and the back crystal sensor. Apple's built-in ECG app classifies results into basic categories: sinus rhythm, atrial fibrillation, inconclusive, or poor recording. Third-party analysis apps can provide more detailed interpretation — examining P-wave morphology, QRS duration, QT interval, and ST segment — giving you a deeper understanding of your heart's electrical activity beyond the basic classification.
What can a third-party ECG app tell me that Apple's built-in app can't?
Apple's built-in ECG app provides a basic classification (sinus rhythm vs. AFib) and a PDF export. Third-party analysis apps can examine additional parameters: heart rate variability from the ECG trace, QT interval (important for medication monitoring), ST segment changes (relevant for ischemia), P-wave characteristics, and QRS complex duration. They can also track these metrics over time to identify trends, compare readings across different dates, and provide more detailed explanations of what each finding means.
What does sinus rhythm mean on Apple Watch ECG?
Sinus rhythm means your heart's electrical activity is originating from the sinoatrial (SA) node — the natural pacemaker in the upper right chamber of your heart — and following the normal electrical pathway. This is the expected, healthy rhythm for most people. It indicates regular heartbeats with consistent intervals and a normal electrical pattern. However, sinus rhythm alone doesn't rule out all heart conditions; it specifically means the rhythm origin and pattern are normal.
Should I see a doctor after an irregular ECG reading?
If your Apple Watch flags "atrial fibrillation" or "irregular rhythm," you should consult your doctor, but don't panic. A single reading is not diagnostic — movement during recording, poor skin contact, cold hands, or caffeine can cause false readings. Take 2-3 additional readings while sitting still with your arm on a flat surface. If multiple readings show irregular results, or if you're experiencing symptoms like palpitations, dizziness, shortness of breath, or chest discomfort, schedule an appointment promptly. Bring your ECG recordings to show your physician.
How do I export Apple Watch ECG data?
Open the Health app on your iPhone, go to Browse → Heart → Electrocardiograms (ECG). Tap any recording to view it, then tap "Export a PDF for Your Doctor" to generate a clinical-format PDF that you can share via email, AirDrop, or messaging. For bulk export of all ECG data, go to your Health profile icon → Export All Health Data, which creates a ZIP file containing all ECG recordings in XML format. Third-party apps can also access ECG data through Apple HealthKit with your permission.
How accurate is Apple Watch ECG compared to a hospital ECG?
Apple Watch records a single-lead ECG (Lead I), while a hospital ECG uses 12 leads for a comprehensive view of the heart from multiple angles. For detecting atrial fibrillation, Apple Watch has been validated with high sensitivity (98.3%) and specificity (99.6%) in Apple's own clinical study. However, it cannot detect many conditions that require multiple leads, such as ST-elevation myocardial infarction (heart attack), bundle branch blocks from certain angles, or posterior wall events. It's a screening tool, not a diagnostic replacement for clinical ECG.
What does an inconclusive ECG result mean?
An inconclusive result means the algorithm couldn't confidently classify your heart rhythm. Common causes include: heart rate below 50 or above 120 BPM (outside the algorithm's optimized range), movement during recording, poor electrode contact (dry skin or loose watch fit), or certain arrhythmias that don't fit the sinus/AFib classification. Try retaking the reading while sitting still, ensuring the watch is snug, and your finger is firmly on the crown. If you consistently get inconclusive results, it's worth mentioning to your doctor.
What is the relationship between ECG readings and heart rate variability (HRV)?
ECG and HRV are closely related but measure different aspects of cardiac function. An ECG records the electrical activity of your heart — the P-wave, QRS complex, and T-wave that represent each heartbeat cycle. HRV is derived from ECG data by measuring the time intervals between consecutive R-peaks (the tallest spike in each QRS complex), called R-R intervals. These beat-to-beat variations reflect autonomic nervous system function. While Apple Watch's built-in ECG app focuses on rhythm classification (sinus vs. AFib), the same underlying electrical data can be analyzed for HRV metrics like RMSSD and SDNN, giving deeper insight into your cardiovascular and nervous system health beyond simple rhythm detection.
Can Apple Watch ECG data help monitor autonomic nervous system health?
Yes. Although Apple Watch ECG is primarily designed for arrhythmia detection, the underlying electrical data contains rich information about autonomic function. R-R interval analysis from ECG traces reveals the balance between your sympathetic (fight-or-flight) and parasympathetic (rest-and-digest) nervous system branches — the same data used to calculate heart rate variability. Over time, tracking ECG-derived metrics like heart rate variability trends and QT interval variability can provide early indicators of autonomic dysfunction, which is associated with conditions from diabetic neuropathy to elevated cardiac risk. Third-party ECG analysis apps can extract these deeper autonomic metrics from your Apple Watch recordings.