 The last decade of the 19th century saw the emergence of a new era in which doctors began using technology such as x-rays and electrocardiograms alongside traditional methods like physical exams and medical histories to diagnose heart diseases. This was followed by a series of breakthroughs in the early 20th century, including the development of the 12-lead electrocardiogram, which has become an essential part of the initial evaluation of patients with cardiac issues. Healthcare professionals at all levels use electrocardiograms to quickly identify potential problems and make informed decisions. Understanding the underlying causes of electrocardiogram patterns can help reduce errors and improve patient outcomes. This article was authored by Joseph Lindsay and Mad Al-Ghatrif.