Our hearts are vital pumps. Just like any pump they work best at the pressures for which they are designed. But unlike most mechanical pumps, the heart does adapt to working under pressures for which it was not necessarily designed. It does this by thickening to accomplish work at a higher pressure, just as other muscles in our body thicken when we are forcing them to do heavy labor on a chronic basis. Just think of the thick and heavy arms of the weight lifter. But there is a problem with this...