The term "cardiac conditions" refers to a broad range of medical conditions that have an impact on the heart, an important organ in the body that pumps blood and distributes oxygen and nutrients to different parts of the body. Coronary artery disease, a heart attack, heart failure, and other illnesses that affect the heart are all included under the umbrella phrase of "heart disease." Arrhythmia: An aberrant heart rhythm is one in which the heart beats too quickly, too slowly.