Cardiovascular Nurses work in many different environments, including coronary care units (CCUs), cardiac catheterization, intensive care units (ICUs), operating theaters, heart rehabilitation centers, clinical research, cardiac surgery departments, and cardiovascular intensive care units. Cardiac nursing is a special nursing field which works with patients who suffer from different conditions of the cardiovascular system. Cardiac nurses help treat and care conditions such as unstable angina, cardiomyopathy, coronary artery disease, congestive heart failure, infarction of myocardium and cardiac arrhythmia under the direction of a cardiologist. Cardiac nurses perform post-operative treatment on a surgical unit, stress test evaluations, cardiac monitoring, vascular monitoring, and health evaluations. Cardiac nurses work in various kinds of environments, involving coronary care units (CCU), catheterization of heart, intensive care units (ICU), operating theatres, cardiac rehabilitation centers, clinical research, wards for cardiac surgery, cardiovascular intensive care units (CVICU), and cardiac medical wards.