An EKG can show how fast your heart is beating, whether the rhythm of your heartbeats is steady or irregular, and the strength and timing of the electrical impulses passing through each part of your heart. You may have an EKG as part of a routine exam to screen for heart disease. This test also is used to detect and study heart problems such as heart attacks, arrhythmia or irregular heartbeat, and heart failure. Results from this test also may suggest other heart disorders.