Junk food, desk jobs and sedentary lifestyles all contributed to an American population with less than healthy heartbeats. According to the American Heart Association's site, cardiovascular disease is the country's No. 1 killer, claiming the lives of more than 40 percent of the 2.4 million Americans who die each year. The site offers free access to reports pertaining to heart-related health problems. Free brochures on heart-healthy living can be downloaded in English and Spanish.