The bradycardias, like the tachycardias, can be attributed to abnormalities in impulse formation and/or to abnormalities in impulse transmission. In the bradycardias, the rate of impulse formation is slowed abnormally or impulse transmission is blocked. This results in a slowing of the rate, the presence of abnormal pauses and the emergence of escape beats and rhythms. In this chapter, we will discuss the electrocardiographic presentations of the bradycardias and group beating. We will also illustrate how the use of ladder diagrams contributes to arriving at the correct diagnosis of the rhythm disturbance.