CathSource vs EP Calipers
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
CathSource
A comprehensive medical reference focused on cardiac catheterization and angiography. It offers a searchable index of specialized topics, a database of videos of common and rare findings, and a collection of images including hemodynamic formulas and tables.
- Searchable index of cardiac catheterization topics
- Database of coronary angiogram, ventriculogram, and aortogram videos
- Image database with hemodynamic formulas and tables
- Covers common and rare cardiovascular pathologies
- Developed by practicing Interventional Cardiologists
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CathSource (from the creators of ECGsource) is an up-to-date medical reference devoted exclusively to cardiac catheterization and angiography. Developed by practicing Interventional Cardiologists for both specialists and trainees in the field of cardiovascular disease, CathSource offers the following content: * Searchable index of specialized topics including: Normal Coronary Anatomy Anomalous Coronary Arteries Coronary Artery Aneurysms Myocardial Bridging Takotsubo Cardiomyopathy Plaque Rupture & Thrombus Standard Views of Angiography Left Ventriculography Coarctation of the Aorta Femoral Artery Access for Angiography Radial Artery Access for Angiography Intravascular Ultrasound (IVUS) Optical Coherence Tomography (OCT) Fractional Flow Reserve (FFR) Hemodynamics: Intracardiac Pressures Hemodynamics: Intracardiac Waveforms Hemodynamics: Cardiac Output Hemodynamics: Intracardiac Shunts Hemodynamics: Aortic Stenosis Hemodynamcis: Aortic Regurgitation Hemodynamics: Mitral Stenosis Hemodynamcis: Mitral Regurgitation Hemodynamcis: Constriction Hemodynamics: Restriction * Searchable database containing more than 30 videos (coronary angiograms, ventriculograms, and aortograms) of both common and rare findings in the cardiac catheterization lab * Searchable database of over 65 images including hemodynamic formulas, tables, and figures CathSource provides a detailed overview of important cardiac catheterization and angiography topics, incorporating educational images/videos as well as reviews of pertinent medical literature. CathSource is the ideal application to assist you in understanding and recognizing cardiovascular pathology in the catheterization lab.
EP Calipers
This medical app allows users to measure intervals and angles on electrocardiogram (ECG) images. It's designed for healthcare professionals to accurately analyze ECGs from photos or PDFs, aiding in calculations like heart rate and QT intervals.
- Measure ECG intervals
- Measure ECG angles
- Calculate mean heart rate
- Determine corrected QT interval
- Analyze ECG photos and PDFs
- Supports Brugada syndrome beta angle measurement
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EP Calipers provides electronic calipers to measure intervals on images of electrocardiograms (ECGs) or electrophysiologic recordings. Doctors, nurses and medical technicians photograph and send ECGs to each other via email and messaging using smart phones and tablets. It is difficult and inaccurate to make measurements on these images with mechanical calipers. EP Calipers can be used to make accurate ECG measurements and do calculations such as determining mean heart rate and corrected QT interval. Angles such as the beta angle in Brugada syndrome can be measured as well. Analyze ECG images you photograph or store on your device, as well as PDF files, such as ECGs generated by the AliveCor Kardia™ device.
Screenshots
Verdict
The clearest difference is price: CathSource at Free against EP Calipers's $1.99. CathSource also leads on ratings volume (23 vs 6). EP Calipers's advantage is rating (2.3 vs 1.6) and chart position (#186 vs unranked). On review sentiment, update cadence, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
CathSource is free to download; EP Calipers costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.
EP Calipers holds the better App Store score, 2.3 against 1.6. Both are backed by a comparable volume of ratings — 23 and 6 respectively. Written reviews point the same way: 43% of CathSource's written reviews are positive against 50% of EP Calipers's.
CathSource ships an update every 2 months, EP Calipers every 3 months. The most recent releases landed on September 18, 2026 and September 13, 2026 respectively.
| Parameter | CathSource | EP Calipers |
|---|---|---|
| Price | Free — better | $1.99 |
| Rating | 1.6 (23 ratings) | 2.3 (6 ratings) — better |
| Positive reviews | 42.9% of reviews | 50.0% of reviews — better |
| Number of ratings | 23 — better | 6 |
| Update frequency | Every 2 months — better | Every 3 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Best chart rank | — | #186 — better |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 18.5 | 14.0 — better |
| Further details — not scored | ||
| Size | 79 MB | 9 MB |
| Age rating | 12+ | 12+ |
| Developer | ECGsource LLC | EP Studios |
Customer experience
CathSource
EP Calipers
In-app purchases
CathSource
No in-app purchases
EP Calipers
No in-app purchases








