An electrocardiograph or ECG machine is a non-invasive device for recording the electrical activity of the heart. Leads are affixed to the patient's chest with an adhesive gel that promotes transmission of electrical impulses to the ECG machine, which then translates the heart's electrical activity into line tracings on paper. ECG machines allow for the diagnosis of specific cardiac abnormalities, such as cardiac dysrhythmia, myocardial infarction and pulmonary embolism. The standard ECG machine is a 12-lead, which uses six electrodes on the chest and one on each limb for a total of 10 electrodes. Smaller ECG machines with just two or three leads are also available and are particularly useful in mobile or resource-poor settings.