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.
HCM is the second most common form of cardiomyopathy. If you have HCM, it means that the walls of your heart are thicker than they should be. Some thickening is normal for healthy people who exercise or who play competitive sports. But with HCM, the thickening becomes extreme. In time, the thickening of the heart muscle can cause the heart to get bigger, or enlarge.