Ruya Maeda is a well-known professor in the field of cardiovascular medicine in Japan. He is a dedicated, enthusiastic and patient person in electrocardiogram education. Over the years, he has edited and published nearly twenty books on electrocardiography, and has worked tirelessly to popularize electrocardiogram education. He described his experience as "an electrocardiogram life." The author said in the preface: "Electrocardiography is not difficult to learn" and it is the hope of writing this book to "make readers fall in love with electrocardiography after reading this book".