EP Diagram is available for the Mac or iPad. Use it to draw electrocardiographic ladder diagrams for didactic purposes. The app includes various editing tools to make drawing these diagrams as easy as possible. The resultant diagrams are saved as files and can be exported as images for publication. Diagrams can be scrolled and zoomed and can display interval measurements in milliseconds after calibration.
Here is a YouTube video on basic operation of EP Diagram. A video on advanced use and a blog post on the app are coming soon.
Here is a tutorial on using app preferences with EP Diagram.
Here is how to edit diagrams.
How to add atrial fibrillation to a diagram.
How to repeat a pattern.
Here is a screenshot from the Mac version: