Heart is undoubtedly the most important organ of the body. It pumps blood to all the organs, and carries away carbon dioxide and other waste products. When the arteries and blood vessels around our heart are damaged, their functioning is affected and the heart is not able to pump blood properly. These issues are collectively known as heart diseases.
As we age, our heart also ages with us. The natural pacemaker in our heart controls the heartbeat. With age, it loses few cells resulting in slower heart rate. Some people also experience arrhythmia (abnormal rhythm). Baroreceptors monitoring the blood pressure become less sensitive. As a result, elders experience dizziness. Production of red blood cells reduces, hence there is slower response to blood loss, resulting in anemia. Immunity also goes down due to reduction in white blood cells.
Watch this video which explains what exactly happens with your heart as you age.