An electrocardiograph is the machine that records the heart’s electrical activity. It is the box, the cables, and the screen; what it prints or shows is the electrocardiogram. The ending -graph here means “the thing that writes.” A technician wheels it to the bed, sticks on the pads, and runs the test. Hospitals usually say ECG for the machine and the test alike, so you may never hear the long word at the bedside. It is a technical, medical word, more at home in a catalogue or a textbook than in a patient’s mouth. Though actually, it is easy to mix with the electrocardiogram because both shorten to ECG, and even doctors are not always careful. It is not an ultrasound machine, which uses sound to make a picture, and it is not a pacemaker, which sits inside the body and helps the heart beat. The electrocardiograph stays outside, looks, and writes.

心電圖機