The aim of this book is to guide the students and doctors about the basic concepts in ECG, its interpretation and recognition of cardiac abnormalities. It is also my intention to include common abnormalities in ECG and common cardiac problems that will help the students in any specialty of medicine, especially those who will appear in any examination. There is no doubt that basic concept of ECG is unchangeable. Only during discussion of ECG changes in different cardiac diseases, new informations investigations and management have been added.