The heart is a muscle, about the size of a fist, whose main job is to pump blood to all parts of the body, bringing needed nutrients and oxygen and delivering waste products to other organs for removal. The heart has four chambers. The upper two are the atria (the right and the left atrium) and the lower two are the right and left ventricles. These chambers contract in a regular sequence, or rhythm (the heartbeat), and these contractions enable the heart to pump blood. "Heart disease” is any disease or condition that negatively impacts the heart's function. Common forms of heart disease are congestive heart failure, coronary artery disease and arrhythmia. heart disease affects more than 20 million Americans, and family history is not the only risk factor. Heart Disease is one of the most-covered and discussed topics among Second Opinion doctors and patients.