What does "electrocardiogram" mean and what does it detect?

An electrocardiogram, abbreviated ECG or EKG, is a recording of the electrical activity of the heart over time. The term breaks into electro meaning electrical, cardio meaning heart, and gram meaning a record. Electrodes placed on the skin detect electrical impulses generated by the heart as it contracts and relaxes. An ECG detects arrhythmias, myocardial infarction, chamber enlargement, electrolyte imbalances, and effects of cardiac medications.