Electrocardiography is a transthoracic recording over a period of time. Electrical activity is detected and recorded via electrodes attached to the outer surface of the skin. The recording produced by this noninvasive procedure is termed as electrocardiogram. ECGs are used to measure the rate and regularity of heartbeats as well as the size and position of the chambers, the presence of any damage to the heart, and the effects of drugs or devices used to regulate the heart. is the clearest and most accessible guide available to the application and interpretation of the ECG in clinical practice. The book proceeds from the belief that ECG patterns should not be memorized, but rather must be understood based on how they originate; it is only by achieving this level of understanding that clinicians can make the most informed diagnoses and thus manage patient care with complete confidence. This fully revised 5 edition: