An EKG shows how fast the heart is beating and shows its rhythm (steady or irregular) in 12 different places on the body at the same time. It also records the strength and timing of the electrical signals as they pass through each part of the heart. 

An EKG can help reveal a number of heart problems. This is especially true if doctors can compare a current EKG recording to an older one. EKG recordings can also reveal. An EKG can help doctors diagnose: 

• A Heart attack, whether it is happening now or has happened in the past.
• Lack of blood flow to the heart muscle
• An irregular heartbeat
• A heart that does not pump forcefully enough 
• Disease in the heart valves between the different heart chambers 
• Birth defects in the heart.