My physiology professor called them "cartoons".
One of our docs here called them "valentines".
However you refer to them, the diagrams that comprise Congenital Heart Disease, A Diagrammatic Atlas are, without a doubt, indispensable for students and practitioners of pediatric echocardiography. Sadly, according to most online retailers, this atlas is no longer published. If you can find a copy anywhere- grab it and don't let go.
Fortunately for those without a hardcopy, many of the diagrams have been published on the web, with permission from the editors, at the Nevil Thomas Adult Congenital Heart Library. The website is a terrific collection of information, not the least of which is their collection of "CHD Heart Pictures".
Why every abnormal echocardiogram report doesn't include a diagram like those from the atlas is beyond me.
By the way, check out paint.net for a rockin', free image editor.