The study of the heart’s structure and function is known as Cardiology. It’s a medical specialty that focuses on the nature and cardiovascular system. A cardiologist is a person who diagnoses and treats coronary artery disease (CAD). Cardiologist treats, Congenital Heart Defects (CHD), arrhythmia (an abnormality of the heart), heart failure, and valvular heart disease. The range of cardiology treatment is from non-invasive office visits to the invasive surgical process.