Not all atrioventricular blocks occur in the atrioventricular node. Understanding the physiological concept behind the various blocks makes recognizing the relevant ECG indications easier. Furthermore, the implications to patients are clear when healthcare providers understand the level of the block and the dangers the block may impose. Until a more accurately descriptive classification system of conduction blocks becomes universally accepted, the current labels will continue to be used. It is imperative that nurses, particularly those caring for cardiac patients, recognize and understand the ECG indications of various degrees of block.