In this chapter, ECG changes in different types of cardiac diseases have been included. The typical findings of ECG in these diseases have been discussed in a systematic way so that students can get familiar with all variations of ECG. Related questions and answers are also provided so that any student or busy practitioner can quickly have a comprehensive knowledge about a disease without going through voluminous text books. In some common diseases, basic management has been provided as well. The chapter is precise and to the point in giving informations and does not overburden its readers with unnecessary details that is not relevant in a clinical setup.