Holter monitor is an continuous electrocardiogram monitors and analyzes the change of heart rate under active and quiet state. It helps record and monitor abnormal waves. It is often use to assess all types of abnormal heart rhythm, detects if myocardial ischemia or silent ischemia occurs within 24 hours, it provides accurate and reliable data to diagnose heart disease. It shows that there is a higher detection rates of coronary artery disease in clinical applications