Review of the anatomy and physiology of the heart, focusing on the circulatory system and the electrical activity of the heart. Topics: how to transport and prepare a patient for electrocardiogram; EKG paper and measures; cardiac rate determination; cardiac cycle; EKG waves and intervals; interpretation of waves and problems which may occur while taking an EKG; special recording of EKG; the EKG and the most common cardiac arrhythmias: the EKG in the myocardial infarction.