The left ventricle is the chamber of the heart that pumps oxygenated blood to the entire body. The aorta is the main artery leading from the heart to the entire body. It causes resistance to the forward ejection of blood from the left ventricle. It is generally a progressive process, meaning the amount of narrowing and obstruction may increase with time. The effects of the obstruction are also progressive and may not cause symptoms initially but may cause problems as time goes by.
Symptoms develop when the heart can no longer overcome or compensate for the obstruction.
Resistance to forward blood flow out of the left ventricle will increase the work the heart has to do to pump blood forward. This also causes the pressure inside the left ventricular cavity to start to climb. Unlike a thick arm muscle however, a thick ventricle is not desirable and may get stiff and not work properly. A thick, stiff ventricle over a long period of time may not be able to maintain a vigorous squeeze and can then dilate and fail. The coronary arteries that feed the heart muscle with blood and oxygen arise just beyond the aortic valve and may not get enough blood to adequately supply the heart muscle.