A Cardiologist is an Internal Medicine, or for children - a Pediatric, medical doctor with additional qualifications enabling specialization in the evaluation and management of disorders involving the cardiovascular system. Cardiac diseases include common conditions such as irregular heart rhythms, high blood pressure, angina (chest pain) or coronary artery disease, and congestive heart failure. Cardiologists administer tests like EKGs, echocardiograms and treadmill tests (exercise electrocardiogram) that assess a person's heart structure and function.