Cardiac catheterization, developed for clinical use by the German physician Werner Forssmann in the 1930s –when he catheterized himself through his own forearm– remains the gold standard for the investigation — and in some cases, management — of a variety of cardiac and coronary conditions.

While these procedures are primarily performed by cardiologists and supervised cardiology fellows, an appreciation for cardiac catheterization represents a valuable skill for internal medicine residents as well as medical students interested in cardiology.

The CathSource app, developed by Drs. Bilhartz and Mahjoobi (cardiologists from Texas A&M) of ECGsource LLC and sponsored by Scott & White Healthcare, aims to assist healthcare professionals in the understanding and recognition of cardiac pathology via cardiac catheterization multimedia.

ECGsource LLC develops materials to help medical trainees prepare for the cardiology boards, and originally focused on EKG interpretation (their EKG database now features over 500 unique EKG’s).

ECGsource LLC has since expanded to offer materials providing instruction on echocardiograms and catheterizations, developing similar EchoSource and CathSource databases.  Similar to their ECGsource app, the CathSource app is a scaled-down version of (or supplement to) the full database (which costs $99/year for individuals) at

Read below the jump to learn more about how the CathSource app can deepen your appreciation for cardiac catheterization procedures with virtual cath images and videos.

The CathSource app’s user interface is impressively streamlined, offering only two options along the bottom bar—index and images.



The CathSource app includes the following topics via the index (the sections on IVUS and OCT were added with the latest update to Version 1.2):

  • Normal Coronary Anatomy
  • Anomalous Coronary Arteries
  • Coronary Artery Aneurysms
  • Standard Views of Angiography
  • 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


As an example, here we explore aortic coarctation, finding the topic through the searchable index. The page for aortic coarctation includes well-written sections on overview, presentation and prognosis, and evaluation and management, with references cited in the text.

The most intriguing and unique feature of the CathSource app is, of course, the catheterization films.  Note the associated caption explaining what to look for and appreciate on the film.

The catheterization films, as seen here, are solid-quality, include the associated tracing, and can be easily navigated and paused.

As a second example, we show the section on the hemodynamics of aortic stenosis.  This section, while without an associated catheterization film, includes several formulas and other images.  This section discusses the Gorlin and Hakki formulas, the correlation between mean and peak-to-peak valvular gradients, gradient measurement, and aortic valve resistance, including citations where appropriate.


9This section of the hemodynamics of aortic stenosis includes several good-quality images (which cannot, however, be selected or zoomed while viewed via the topic) referenced in the text to help users understand the presented material.

The other aspect of the app facilitates the more convenient searching and viewing of images and films otherwise embedded in the various topics found in the index.  As seen here, the captions for each image are included on the search screen before selecting the particular image or film.

Here we show a representative figure which illustrates a normal right-dominant coronary anatomy, which can be zoomed and panned, unlike when it is embedded in a topic.



And finally, here we show a representative catheterization still-image depicting the left main anatomy, with vessels labeled.


  • The CathSource app costs $3.99 on the iTunes app store.


  • Over 30 high-quality, easily-navigated catheterization videos and 65 images
  • Impressive breadth of cardiac pathology discussed in the app
  • Developed by interventional cardiologists with references cited in the text
  • Customized for both the iPhone and iPad


  • – A quiz or tutor mode featuring cases and films with associated questions may have been a nice feature for the app to consolidate mastery of the presented material (as with the full-fledged CathSource database)
  • – Images and figures cannot be zoomed when viewed via the topic, only via “images”


  • The CathSource app represents a worthwhile purchase for residents or medical students interested in cardiology, as it uses catheterization films and associated figures to help depict and discuss cardiac pathology as seen via cardiac catheterization.
  • The app could potentially be useful for patient education as well, due to the plethora of cardiac cath videos and pictures — helping patients get an in-depth understanding of their upcoming procedure.

iTunes Link: