An electrocardiogram (ECG) is a medical test that detects heart problems by measuring the electrical activity generated by the heart as it contracts. A doctor may recommend an ECG for people who may be at risk of heart disease because there is a family history of heart disease or because they smoke are overweight have diabetes high cholesterol or high blood pressure. A doctor may also recommend an ECG for people who are displaying symptoms such as chest pain breathlessness dizziness fainting or fast or irregular heartbeats.The ECG is a safe and non invasive procedure with no known risks.