On the left you see what a healthy human heart should look like. On the right is an enlarged human heart. Alcohol consumption, tobacco use, and high blood pressure contribute to an enlarged heart. People with an enlarged heart often suffer more health ailments, a lower quality of life, and premature deaths. In this case, a bit of self-discipline and a few hours of cardiovascular exercise could have saved this persons life.
Above is a cross-section of heart disease. As you can see, the artery is almost completely closed due to plaque build up. The buildup of plaque is a classic symptom of cardiovascular disease, a condition that is the number one killer of Americans today. A high-fat, unhealthy diet combined with a sedentary lifestyle are two key components to developing arteries that look like the one above.
For those that lead a sedentary lifestyle and pay little attention to their diet, there are two options for you down the road; a heart transplant, or death. Needless to say, the overwhelming majority do not get the needed heart and simply die from a highly preventable cause. The above is not something you want to ever have to rely on.
The valves of the heart are very delicate in appearance, but actually very tough. They pump almost a litre of blood through your body each day. The blood follows a 60,000 mile long track of arteries and blood vessels to supply your entire body with a constant supply of oxygenated blood. When these valves become weak from disease, blood flow is impeded resulting in terrible consequences.
Finally, we see what a healthy heart should look like. This image was taken during an angiogram. Doctors inject an opaque fluid which shows a very detailed view of the arteries and blood vessels in the heart. Notice how there are no blockages or plaque buildup forming in this heart. Odds are very likely this person engages in physical fitness multiple times a week.