Cardiac investigations often need to be performed in patients with symptoms suggestive of heart disease. Cardiac investigations may also be appropriate for people with no symptoms but who have risk factors for heart disease. The most common cardiac investigation that is performed is the ECG or electrocardiogram. This is the most basic test and provides information on the general health of the heart and the conduction system and whether the patient has had a previous heart attack. Information on other specialized cardiac investigations, such as the exercise treadmill test, echocardiogram, coronary angiogram and electrophysiological (EP) study is provided below.