Figure 1.

Hierarchy of preparations and techniques in cardiac electrophysiology. Preparations range from organism (mouse-to-human), isolated heart, multicellular preparations (e.g. slice/wedge or papillary/trabeculae preparations), isolated cardiac cells (e.g. atrial, ventricular, nodal or Purkinje cells) to ion-channel expression systems (e.g. HEK). The associated techniques for measuring cardiac function are shown on the right. Comparable preparations (syncytium and single cell) for stem-cell-derived cardiomyocytes are indicated in a separate panel.