this article from NY times discusses the affect exercise has on heart health and preventing heart diseases. you don't have to be a fitness fanatic to make efforts toward a healthier future. prevention is always better than cure!
Heart failure, sometimes known as congestive heart failure, occurs when your heart muscle doesn't pump blood as well as it should. Certain conditions, such as narrowed arteries in your heart (coronary artery disease) or high blood pressure, gradually leave your heart too weak or stiff to fill and pump efficiently. Heart failure develops over time as the heart's pumping action grows weaker. The condition can affect the right side of the heart only, or it can affect both sides of the heart.
Causes And Diagnosis Of Congestive Heart Failure. "About 5 million Americans suffer from heart failure, of them die each year" according to Medline Plus (National Institutes of Health & Human Services.
Preload is the stretch. The amount of volume being returned to the right side of the heart from systemic circulation. Afterload is the squeeze. The amount of resistance the left side of the heart has to overcome in order to eject blood.