This chapter is written in the question and answer format, which gives the description on the cardiology. Chest pain is a common symptom of cardiac disease. However, it can be due to noncardiac causes such as anxiety, disease of the respiratory, musculoskeletal or gastrointestinal systems. This chapter covers the heart sounds, murmurs, conduction system of the heart, electrocardiogram (ECG), apical impulse, ischemic heart disease (IHD), coronary artery disease, acute coronary syndrome, hypertension, rheumatic heart disease, valvular heart disease, infective endocarditis, heart failure, cardiac arrhythmias, diseases of the myocardium, congenital heart diseases, diseases of the pericardium, pulmonary hypertension, sudden cardiac death (SCD), cardiac arrest, Cor pulmonale, diseases of vessels, Raynaud’s phenomenon and Raynaud’s disease, circulatory failure, pulmonary embolism and venous thrombosis, disorders of blood lipids and lipoproteins, lipodystrophy, straight back syndrome (SBS), cardiac tumors, and digoxin. Ischemic heart disease (IHD) is a group of heart diseases in which there is an imbalance between myocardial blood supply and its oxygen demand. IHD is the leading cause of death in both males and females. Angina pectoris is clinical syndrome that presents as paroxysmal and recurrent attacks of substernal or precordial chest discomfort due to transient myocardial ischemia, which falls short of inducing necrosis of myocardial cell.