Holter monitoring is a non-invasive diagnostic test used to assess and monitor the electrical activity of the heart over an extended period, typically 24 to 48 hours. Named after its inventor, Dr. Norman J. Holter, this portable device records the heart's rhythm continuously, providing a comprehensive analysis of cardiac activity during a person's daily activities. Small electrodes are attached to the chest, and the Holter monitor, a lightweight device, is worn inconspicuously on a belt or shoulder strap. This monitoring method is particularly valuable in detecting irregularities or abnormalities that may not be evident during a brief visit to a healthcare facility. Holter monitoring is commonly employed to diagnose arrhythmias, evaluate the effectiveness of anti-arrhythmic medications, and investigate unexplained symptoms such as palpitations, dizziness, or fainting episodes. The data collected by the Holter monitor allows healthcare professionals to analyze the heart's electrical patterns and make informed decisions about appropriate treatments or interventions. This continuous monitoring plays a crucial role in understanding and managing cardiac conditions, contributing to improved patient care and overall cardiovascular health.