One of the most immediate ways to understand aortic stenosis, and how it affects blood pressure and the heart, is by watching a Transcatheter aortic valve implantation (TAVI) procedure. Catheters are placed in both the left ventricle (LV) and the aorta. The measuring of pressures in the left ventricle overlaid on the pressure in the aorta is telling. Especially seeing how they are equalised after getting a new aortic valve that restores free flow through the LV outflow tract.
Below, you’ll see the left ventricle pressures in yellow, and aortic pressures in red (colors represented both in the graph tracings and the numbers left of them).
Above: Pre-TAVI deployment you can see the effects of the stenotic aortic valve: Pressures in the left ventricle reach much higher levels than in the aorta. The heart is squeezing hard to try to get enough blood moving into the aorta to maintain blood pressure and cardiac output.
You can also see how the LV pressures increase abruptly and are not eased by the opening of the stenotic aortic valve. Rather, the pressure in the aorta is rising more slowly, as the blood squeezes through the narrow valve.
LV pressure 215/7, Aortic pressure 140/60. These very high pressures generated in the left ventricle makes the ventricle hypertrophic, and will eventually make it dilated as in end stage dilated cardiomyopathy. This heart is still only at the hypertrophic stage.
Above: Post TAVI deployment: There is now free flow over the aortic valve, as shown by the systolic pressures equalised between the left ventricle and the aorta. It also shows how the pressure in the left ventricle falls to zero as the aortic valve closes, and it is the myocardium contracting that generates the blood pressure, and as it meets and surpasses the diastolic pressure in the aorta, the aortic valve opens, and the LV and aortic pressures rise simultaneously over the now non-stenotic, open aortic valve.
LV pressure 156/6, Aortic pressure 156/39.