A Cardiologist diagnoses and treats many cardiovascular conditions, including coronary heart disease, arrhythmia, angina, heart failure, heart defects and heart disorders. They also provide care for people who have suffered heart attacks and strokes. When they perform their job duties proficiently, Cardiologists can reduce the risk of premature death for people suffering from diseases that affect the cardiovascular system and allow them to lead fuller lives. Their duties and responsibilities directly impact the overall quality of care that a health care facility provides as well as patient satisfaction rates. In addition, they can limit the liabilities of their employers by following established standards of care.