What can anatomy teach the electrophysiologist for diagnostic procedures?

Even for a basic study, the electrophysiologist needs to have a clear mental picture of cardiac anatomy when positioning the diagnostic catheters. This review highlights some of the features of the four cardiac chambers relevant for translating anatomic knowledge into an understanding of fluoroscopy images and electrograms. Integration of images from real cardiac anatomy into three-dimensional mapping based on electrograms and "virtual" anatomy is crucial for the success and safety of diagnostic and therapeutic electrophysiological procedures.