Why is an ECG used? β It is used to diagnose many common heart problems in people of all ages and is also used to identify and detectπ Irregular heartbeat If blocked or narrowed arteries in your heart (coronary artery disease) cause chest pain or a heart attack If you have had a previous heart attack How successful some heart disease treatments are β You may need an EKG if you have any of the following signs and symptoms; Chest pain Dizziness, lightheadedness, or confusion Heart palpitations β Rapid pulse Shortness of breath β Weakness, fatigue, or decreased ability to exercise.