The quad cab has a smaller back seat and a larger bed, the crew cab has a larger back seat and a smaller bed. To compare them you can go to http://www.ramtrucks.com/en/2011/ram_150... and select the Build My Own option from the bottom of the page.
Heart muscle thickening (called cardiac hypertrophy) can be a healthy response to exercise and pregnancy; however, it often occurs in people with high blood pressure, diabetes, heart failure and certain genetic conditions.
The second most common form of heart muscle disease is hypertrophic cardiomyopathy. This disease is characterized by the abnormal growth and arrangement of muscle fibers in the heart (myocardial disarray), leading to excessive thickening of the heart walls.